807 Focus Four: Caught-In/Between Hazards

Glossary

#

• 5-Why Analysis. A method of root cause analysis that involves asking "why" five times to drill down into the causes of a problem.

A

• Absorption. The process by which hazardous substances, such as chemicals, enter the body through the skin, eyes, or mucous membranes. Absorption can lead to systemic health effects, and protective measures like gloves, goggles, and barrier creams are essential to minimize exposure. OSHA and NIOSH recommend regular monitoring of workplace chemicals to mitigate absorption risks.
• Acceleration Hazards. Workplace hazards related to rapid speed changes or force, which can result in injuries such as whiplash, fractures, or sprains. These hazards often occur in workplaces with moving machinery, conveyor systems, or vehicles. For example, sudden stops can lead to dangerous impacts or falls. Prevention strategies include securing machinery with appropriate braking systems, training workers on safe handling, using seatbelts and safety harnesses, and conducting regular maintenance to prevent malfunction.
• Accident. An unplanned and unexpected event that results in injury, illness, property damage, or environmental harm. OSHA requires reporting of certain accidents to monitor and prevent workplace hazards, while NIOSH may conduct research to understand underlying causes and develop prevention strategies.
• Accident Investigation. A systematic process of identifying the root causes and contributing factors of an accident to prevent recurrence. OSHA requires employers to conduct accident investigations for significant incidents, documenting findings, corrective actions, and changes in procedures. The CDC and NIOSH also support research into accident trends to help develop industry-wide safety improvements.
• Accident Costs. The total financial impact of an accident, including direct costs (medical expenses, workers' compensation) and indirect costs (lost productivity, training replacements, and repair). OSHA highlights accident costs as part of its workplace safety evaluations to underscore the economic impact of workplace injuries and illnesses.
• Accountability. The responsibility of individuals and organizations to uphold safety standards, follow regulations, and ensure corrective actions are taken. OSHA holds employers accountable for maintaining safe workplaces, while NIOSH provides resources to help organizations implement effective accountability systems for hazard prevention.
• Acids. Corrosive substances that pose significant health risks, causing burns, respiratory issues, and eye injuries upon contact. OSHA and NIOSH provide guidance on handling acids, including the use of PPE, proper ventilation, and emergency procedures to manage accidental exposure. Safety Data Sheets (SDS) for acids must be available in workplaces to inform workers of specific hazards and precautions.
• Administrative Controls. Policies and procedures aimed at reducing exposure to hazards through changes in how tasks are performed rather than physical changes to the work environment. Administrative controls include job rotation to prevent repetitive stress injuries, scheduling work in non-peak hours to reduce exposure, providing safety training, and enforcing safety protocols. Although not as effective as engineering controls or elimination, administrative controls are crucial when other controls are not feasible.
• Analysis. The process of examining data, incidents, or trends to identify patterns, causes, and effects of workplace hazards. OSHA and NIOSH use analytical processes, including quantitative risk assessments and root cause analysis, to improve safety protocols and develop evidence-based prevention strategies.
• Asbestos. A hazardous, fibrous mineral known for causing serious respiratory diseases, including asbestosis, lung cancer, and mesothelioma, upon inhalation of fibers. OSHA and the CDC regulate asbestos exposure in the workplace, requiring specific protective measures, regular air monitoring, and safe removal practices to minimize health risks. Asbestos-related diseases are often long-term and may take decades to develop, highlighting the importance of strict exposure limits.

B

• Benchmarking. A process of comparing safety performance, practices, or standards against industry peers or best-in-class organizations. Benchmarking helps companies identify areas for improvement, adopt best practices, and set achievable safety goals. OSHA and NIOSH recommend benchmarking as a way to continuously improve workplace safety programs.
• Biohazards. Biological agents, such as bacteria, viruses, fungi, and parasites, that can pose serious health risks to workers, particularly in healthcare, laboratory, and agricultural settings. Exposure to biohazards can lead to infections, diseases, and even pandemics. Prevention strategies include proper sanitation and hygiene practices, using personal protective equipment (PPE) like gloves, masks, and gowns, and vaccination or health monitoring for workers in high-risk settings.
• Biological Monitoring. The measurement of toxic substances or their metabolites in biological samples, such as blood or urine, to assess worker exposure to hazardous chemicals. OSHA and NIOSH support biological monitoring as part of exposure assessment in workplaces handling dangerous substances, providing early detection of potential health risks.
• Biosecurity. Procedures and measures taken to protect workers and the public from exposure to infectious agents or biohazards. In laboratories and healthcare settings, biosecurity protocols help prevent unauthorized access to harmful biological agents, reducing risks of accidental release or contamination. CDC and OSHA guidelines address biosecurity in various occupational settings.
• Blame. The act of assigning responsibility for a fault or error to an individual or group. In safety investigations, modern practices focus on "no-blame" approaches to foster a culture of safety and learning rather than punishment, encouraging hazard reporting and open communication about safety concerns.
• BLEVE (Boiling Liquid Expanding Vapor Explosion). A violent explosion that occurs when a vessel containing pressurized liquid (often a flammable substance) ruptures, causing the liquid to vaporize rapidly. BLEVEs are extremely hazardous and can cause severe damage, injuries, or fatalities. OSHA emphasizes proper storage, handling, and emergency procedures to prevent such incidents.
• Blasting Safety. Procedures and regulations to ensure safety when handling explosives, particularly in construction, mining, and demolition. OSHA requires specialized training, PPE, and clear communication protocols to minimize risks from blasting operations. Blast plans are developed to prevent injuries from flying debris, pressure waves, and accidental detonations.
• Bodily Reaction. Injuries resulting from free body movement or holding a strained or unnatural position, such as twisting or bending awkwardly. Common in tasks that require repetitive or sudden movements, this can lead to sprains, strains, or muscle injuries. Prevention includes ergonomic design, task rotation, and training on safe body mechanics.
• Brainstorming. A collaborative problem-solving technique in which team members generate numerous ideas without criticism or judgment to encourage creative solutions. In hazard identification and risk assessment, brainstorming can be used to identify potential hazards, evaluate risks, and develop control measures.
• Burn Hazard. A risk of injury from exposure to heat, flames, chemicals, electricity, or radiation. OSHA mandates protective measures, such as PPE, fire prevention systems, and training, to control burn hazards in workplaces where there is potential for thermal or chemical exposure.
• Business Continuity Plan (BCP). A proactive plan to ensure that operations continue and critical functions are restored following an emergency, such as a natural disaster or industrial accident. OSHA and the CDC recommend BCPs to safeguard both worker safety and business operations, addressing hazard control, emergency preparedness, and crisis management.

C

• Caught-between Accident. When a person becomes trapped between two objects, often moving or closing together. This hazard occurs frequently with heavy equipment or when workers are in confined spaces. Preventative steps include setting up exclusion zones and using appropriate machine guards.
• Contact-by Accident. An injury that occurs when a person comes into unintentional contact with a harmful substance or material. Examples include exposure to chemicals, electricity, or hot surfaces. Prevention involves hazard communication, protective barriers, and personal protective equipment (PPE).
• Caught-in Accident. An incident where a person, or part of them, becomes trapped or otherwise caught within an opening or enclosure. Examples include trench cave-ins or getting caught in a confined space. Safety measures include proper shoring in trenches, adherence to confined space procedures, and training.
• Caught-on accident. A scenario where a person or part of their clothing or equipment becomes caught on an object, whether moving or stationary. This can cause loss of balance, falls, or entanglement in machinery. Prevention includes wearing fitted clothing, using machine guards, and securing loose items.
• Contact-with Accident. An incident where a person initiates contact with a harmful substance or material, such as intentionally handling corrosive chemicals without PPE. Preventative actions include hazard awareness training, PPE, and safe handling procedures.
• Cause. An event, action, or condition that directly leads to an accident, incident, or unsafe situation. In accident investigations, identifying the root cause is critical for implementing effective corrective actions.
• Cause-Effect Diagram. A visual tool, also known as a fishbone or Ishikawa diagram, used to systematically identify and display all potential causes of a specific problem or accident. It is useful for analyzing complex incidents by categorizing contributing factors.
• Caution Signs. OSHA-mandated signage used to alert workers to potential hazards or risks, such as slippery floors or moving machinery. These signs use standard colors and symbols to ensure hazard recognition and encourage safe practices.
• Chemical. Any substance with a distinct molecular composition that may be used in industrial, manufacturing, or laboratory processes. OSHA and NIOSH regulate the safe handling, storage, and disposal of chemicals to protect workers from harmful exposure.
• Chemical Reactions. Reactions between substances that result in chemical changes, often releasing heat, gas, or light. Hazardous chemical reactions can cause explosions, fires, or toxic releases. Common hazards include acids mixing with bases, flammable liquids near open flames, and oxidizers combined with fuels. Prevention involves storing incompatible substances separately, proper labeling, employee training on chemical safety, and having spill control measures and fire suppression systems in place.
• Checklist. A tool commonly used in safety inspections, audits, and procedure compliance to ensure all steps are completed. OSHA encourages using checklists to verify hazard control and regulatory compliance in workplaces.
• Closed Question. A question that limits answers to specific choices, such as "yes" or "no," or to a factual response. Closed questions are often used in safety surveys or incident investigations to obtain clear, concise information.
• Common Sense. Practical, straightforward judgment based on experience or basic reasoning. In workplace safety, common sense is often emphasized for recognizing and addressing obvious hazards, though it must be paired with formal training and guidelines.
• Common Sense Hazard Recognition. The identification of obvious or immediately apparent hazards based on practical reasoning and experience. While useful, it should complement, not replace, formal hazard assessments and safety training.
• Communication. The exchange of information among workers, management, and regulatory bodies. Effective communication is essential for ensuring safety protocols are understood and followed, especially regarding hazard information, emergency procedures, and safety expectations.
• Component. An individual part of a larger system, structure, or process. In safety and hazard analysis, identifying each component's function and its potential failure modes helps prevent accidents and improve system reliability.
• Confined Space. An area that meets OSHA's criteria for limited entry and exit, large enough for worker access, and not designed for continuous occupancy. Confined spaces, such as tanks or silos, often require permits and special safety protocols due to risks of entrapment, toxic atmospheres, or oxygen deficiency.
• Consensus. General agreement among stakeholders, such as safety committees, workers, and management, often required for implementing changes in workplace safety practices. Consensus helps ensure that new safety measures have buy-in from all parties involved.
• Continuous Improvement. An ongoing effort to improve safety processes, training, equipment, and protocols. Continuous improvement is part of OSHA's recommended practices and helps organizations prevent incidents by regularly evaluating and enhancing safety systems.
• Control Measures. Actions taken to reduce or eliminate risks associated with workplace hazards. Control measures follow the hierarchy of controls, starting with elimination and substitution, then engineering controls, administrative controls, and, lastly, personal protective equipment (PPE). OSHA emphasizes implementing effective control measures as part of a comprehensive safety management system.
• Corrective Action. Steps taken to eliminate the causes of an identified nonconformity, hazard, or incident to prevent its recurrence. OSHA often requires corrective actions following inspections, incidents, or identified violations. Corrective actions might include engineering changes, updated procedures, or additional training.
• Corrective Maintenance. Maintenance performed to repair identified issues or defects and restore equipment or systems to proper working condition. OSHA emphasizes corrective maintenance for ensuring equipment operates safely and preventing malfunctions that could lead to accidents.
• Critical Control Point (CCP). A specific step in a process where hazards can be prevented, eliminated, or reduced to an acceptable level. Identifying CCPs is essential in industries where process safety is critical, and OSHA may evaluate CCPs during investigations to ensure proper controls were applied.
• Critical Incident. An event that causes or could cause severe injury, fatality, or significant property or environmental damage. OSHA requires that critical incidents be reported and investigated to determine root causes and implement preventive measures to avoid recurrence.

D

• DART Rate (Days Away, Restricted, or Transferred Rate). A key safety metric used to calculate the number of work-related injuries or illnesses per 100 full-time employees that result in days away from work, restricted duties, or job transfers. The DART rate provides insight into the frequency of incidents impacting workers' abilities to perform their regular job duties and is essential for identifying areas for safety improvement.
• De Minimis Violation. A violation of OSHA standards that has no direct or immediate relationship to employee safety or health, often relating to minor regulatory infractions. De minimis violations do not result in citations, fines, or required corrective actions, though OSHA inspectors may document them in inspection records.
• Decibel (dB). A unit of measurement used to express the intensity of sound. OSHA sets permissible exposure limits for noise levels in the workplace, with prolonged exposure to high decibel levels posing risks to hearing. Employers are required to implement hearing conservation programs if noise levels exceed certain thresholds.
• Decontamination. The process of removing or neutralizing hazardous substances from employees, equipment, and work areas to prevent contamination and minimize health risks. Decontamination procedures are essential in industries dealing with hazardous chemicals or infectious agents and are required by OSHA and CDC guidelines.
• Deficiency Analysis. A systematic review process used to identify gaps in safety protocols, equipment, or compliance with OSHA and NIOSH standards. Deficiency analyses help organizations pinpoint specific areas requiring improvement to enhance workplace safety and ensure regulatory compliance.
• Designated Area. A location within the workplace identified for specific activities or tasks that may involve hazardous materials or risks. OSHA standards may require designated areas for processes involving hazardous chemicals, allowing employers to isolate risks and provide targeted safety controls.
• Discipline. The practice of training employees to follow safety rules, standards, and codes of conduct through reinforcement or corrective measures. Effective discipline in a safety context includes education, positive reinforcement, and, when necessary, corrective actions to ensure compliance and minimize risks.
• Disinfection. The process of using chemicals to kill or deactivate pathogens on surfaces and equipment, essential for infection control in workplaces with biological hazards. Disinfection procedures are mandated by OSHA and CDC guidelines to protect employees from infectious agents, particularly in healthcare and laboratory settings.
• Distracted. A state in which an employee's attention is diverted from tasks, potentially leading to accidents and errors. OSHA encourages employers to minimize distractions, especially in high-risk environments, to reduce incidents caused by lack of concentration. Examples include mobile phone usage policies and environmental noise controls.
• Dose-Response Relationship. A concept used in hazard assessment that describes the correlation between the level of exposure (dose) to a substance and the severity of the health outcome (response). OSHA and NIOSH use dose-response relationships to establish safe exposure limits for chemicals and physical hazards in the workplace.
• Drill. A planned safety exercise used to test and improve employee response to emergency situations, such as fire, chemical spills, or evacuation procedures. OSHA and NIOSH recommend regular drills to ensure preparedness and identify areas for improvement in emergency response protocols.
• Dust Control. Measures implemented to minimize dust emissions in the workplace, which can pose respiratory hazards or explosion risks. OSHA and NIOSH require effective dust control practices, such as ventilation, wetting, and enclosure, particularly in industries like mining, construction, and agriculture.

E

• Economic Feasibility. An analysis of the cost-effectiveness of a proposed solution or project, weighing the financial benefits against the costs. In occupational safety, economic feasibility considers the financial impact of implementing controls or safety programs to determine if they provide a reasonable return on investment in terms of risk reduction.
• Education. The process of receiving or delivering structured learning and instruction, often in a formal setting, aimed at increasing knowledge and skills. In safety and health, education focuses on informing workers and employers about risks, regulations, and safe practices as required by OSHA, NIOSH, and CDC guidelines.
• Electric Shock. A physiological response or injury resulting from electric current passing through the body. Electric shock can lead to severe injury or death, depending on the current's intensity and path. OSHA provides guidelines to protect workers from electric shock, including proper grounding, insulation, and use of personal protective equipment (PPE).
• Electrical Hazards. Hazards stemming from exposure to electricity, which can lead to electric shock, burns, electrocution, or fires. Risks are particularly high when working with electrical wiring, outlets, circuit breakers, or energized equipment. Prevention includes grounding equipment, maintaining safe distances from electrical sources, using personal protective equipment (e.g., insulated gloves), enforcing lockout/tagout procedures to prevent accidental energizing of equipment, and conducting regular inspections of electrical systems.
• Elimination. The most effective control in the hierarchy of controls, elimination involves removing a hazard entirely from the workplace, making exposure impossible. For example, automating a hazardous task removes the need for workers to perform it. This strategy requires planning in the design phase of a project but is the most reliable way to ensure worker safety.
• Elimination Controls. Safety measures that remove a hazard entirely from the workplace. Elimination is the most effective form of hazard control in the hierarchy of controls, as it permanently eliminates the risk rather than relying on mitigation. Examples include substituting a less hazardous material for a toxic one or automating a process to remove workers from a dangerous task.
• Emergency Action Plan (EAP). A documented plan required by OSHA, outlining procedures for reporting emergencies, evacuating the facility, providing medical assistance, and ensuring employee safety in case of a workplace emergency. EAPs are essential for preparedness and must be regularly reviewed and practiced to ensure worker safety.
• Employee. A person who works for an organization in exchange for wages or salary, typically performing non-executive or operational roles. Employees are entitled to workplace protections and training to ensure their safety and health under OSHA regulations.
• Employer. An individual or organization that hires workers and is responsible for ensuring their safety and health in the workplace by following OSHA standards and other applicable regulations. Employers are accountable for providing a safe working environment, proper training, and necessary safety equipment to prevent workplace injuries and illnesses.
• Engineering Controls. Physical modifications to equipment, processes, or environments designed to reduce or eliminate hazards at their source. Examples include ventilation systems to remove contaminants, machine guarding to prevent contact with moving parts, and noise dampening enclosures. Engineering controls are prioritized over administrative and PPE measures, as they do not rely on worker behavior to be effective.
• Engineering Controls. Physical changes to the work environment or processes that minimize exposure to hazards, including ventilation systems, machine guards, soundproofing, or isolation of hazardous materials. Engineering controls are highly effective because they address hazards at the source, reducing the need for employee reliance on personal protective equipment (PPE) or behavioral controls. Examples include chemical fume hoods, enclosed laser systems, and noise barriers.
• Environmental Health. A field of public health concerned with factors in the environment that can affect human health. In the workplace, environmental health focuses on managing exposures to physical, chemical, and biological agents that could harm workers, ensuring compliance with OSHA and CDC standards.
• Environmental Exposure. Contact with potentially harmful agents present in the surrounding environment, such as pollutants, chemicals, or biological agents. Workers may face environmental exposures due to air quality, chemical spills, or biological hazards. Proper hazard assessment, ventilation, and PPE help minimize these risks in occupational settings.
• Equipment. The machinery, tools, and devices required to perform a job or task. In occupational safety, equipment must be properly maintained, regularly inspected, and used according to manufacturer guidelines to prevent accidents or injuries. OSHA mandates specific safety standards for equipment, including machine guarding and lockout/tagout procedures.
• Ergonomics. The study and design of work tasks and environments to fit the physical abilities of workers, reducing strain and the risk of musculoskeletal injuries. Ergonomic hazards, such as repetitive motions, awkward postures, or excessive force, can lead to conditions like carpal tunnel syndrome, tendonitis, and lower back pain. Prevention includes redesigning workstations, adjusting tools and equipment, using mechanical aids for heavy lifting, and training workers on safe lifting and postures.
• Evaluation. The systematic assessment of processes, practices, or equipment to determine effectiveness, safety, and compliance with standards. In workplace safety, evaluations include hazard assessments, safety audits, and reviews of training effectiveness to ensure ongoing compliance with OSHA and industry regulations.
• Explosives and Explosions. Hazards associated with materials or reactions that release large amounts of energy quickly, potentially causing blasts, fires, and flying debris. These hazards are present in industries involving chemicals, mining, fireworks, and munitions. Prevention strategies include proper storage of explosive materials, adherence to safety protocols, restricting access, regular employee training on handling and emergency response, and having containment systems like blast walls.
• Exposure. The condition of being subjected to a hazardous substance, physical agent, or environment without adequate protection, such as chemical vapors, loud noise, or extreme temperatures. Exposure assessments are essential to evaluate the risk level, determine required controls, and ensure compliance with OSHA exposure limits for various substances.
• Exposure Limit. The maximum amount of a hazardous substance or agent to which a worker can be exposed over a specific period, as defined by regulatory bodies like OSHA, NIOSH, and the CDC. Exposure limits are designed to protect workers' health and are based on scientific research about the effects of long-term or high-dose exposure.

F

• Failure Mode and Effect Analysis (FMEA). A systematic method for evaluating processes or equipment to identify potential failures, assess the likelihood and impact of each failure, and prioritize corrective actions to improve reliability and safety. FMEA is commonly used to preemptively address hazards and is part of comprehensive risk management practices.
• Failure to Abate. OSHA's term for an employer's failure to correct a hazard after being cited in an initial inspection. A Failure to Abate violation results in additional penalties and often triggers further inspections. It highlights the importance of timely and effective hazard mitigation in maintaining workplace safety.
• Fall Arrest. Systems designed to stop a falling worker safely before they hit the ground or any surface below. These systems typically include full-body harnesses, shock-absorbing lanyards, and secure anchor points. Fall arrest is crucial for preventing serious injuries when working at heights, and OSHA mandates specific guidelines for fall arrest equipment and training.
• Fall Positioning. Safety equipment used to hold a worker in place, preventing them from moving into areas where a fall might occur. Fall positioning systems allow workers to perform tasks hands-free while staying securely in place, helping reduce fall risks in elevated work areas.
• Fall Protection Equipment Components. Parts and accessories used in fall protection systems, including full-body harnesses, shock-absorbing and self-retracting lanyards, lifelines, and anchor points. These components are designed to work together to either prevent falls or arrest falls in progress, ensuring worker safety at heights. OSHA requires that each component is properly rated, inspected, and maintained.
• Fall Restraint. Safety systems that restrict a worker's movement to prevent them from reaching an area where a fall could occur. Fall restraint includes anchor points and harnesses connected with non-adjustable lanyards, effectively keeping workers within a safe zone. Fall restraint is considered a proactive form of fall protection and can eliminate the need for arrest systems if implemented properly.
• Fall-To-Below Accident. A fall resulting in a person landing on a surface below where they initially stood, such as falling from a ladder or scaffold. Prevention methods include guardrails, personal fall arrest systems, and proper ladder and scaffold setup.
• Fall-To-Same-Surface Accident. An event where a person falls to the same level or surface on which they were standing, often due to slips, trips, or balance loss. Prevention includes using non-slip flooring, regular cleaning to prevent spills, and ensuring that walkways are clear.
• Fatigue. Extreme tiredness, either mental or physical, that reduces alertness, concentration, and decision-making ability. Fatigue can significantly increase the risk of accidents and injuries in the workplace. NIOSH and OSHA recommend fatigue management programs, including shift scheduling, adequate rest breaks, and worker education to mitigate fatigue risks.
• Feasible. In the context of OSHA regulations, this term refers to safety solutions or controls that are practical and achievable given technological, economic, and operational considerations. OSHA requires employers to implement the most feasible control measures to reduce hazards and protect workers.
• Fishbone Diagram. Also known as an Ishikawa or cause-and-effect diagram, this tool helps identify and analyze root causes of problems by visually mapping out factors contributing to an issue. Often used in incident investigations and hazard assessments, fishbone diagrams allow safety teams to brainstorm potential causes and address underlying issues.
• Flammable. Describes materials that ignite easily and burn quickly. OSHA and the CDC classify flammable substances by flash point, and workplaces must store, label, and handle flammable materials following specific guidelines to prevent fires and explosions.
• Flammability. The ability of a material to ignite and burn. Flammable materials, such as certain gases, liquids, and solids, present risks of fires and explosions, especially when exposed to heat or sparks. Prevention includes proper labeling, storage in ventilated areas, keeping ignition sources away from flammables, using flame-retardant materials, and training workers on fire hazards and emergency response. Fire extinguishers and emergency exits should be readily accessible.
• Foreseeable Hazard. A potential risk or condition that a reasonable person should anticipate, given certain actions, environments, or procedures. OSHA requires employers to assess foreseeable hazards as part of a comprehensive safety program, identifying risks that may not be immediately obvious but could reasonably lead to injury or illness if not controlled.
• Form Observation. The structured examination and documentation of workplace practices, conditions, and behaviors. Form observations are often used to identify and address hazards, ensure compliance, and provide data for incident investigations. OSHA encourages regular form observations to detect and mitigate unsafe practices before they result in injuries.
• Friction. The resistance encountered when two surfaces move against each other. In safety, friction is relevant to slip, trip, and fall prevention. OSHA considers friction a key factor in safe footwear, flooring, and matting, as it affects traction, helping prevent slips on various surfaces.
• Formaldehyde. A highly flammable and toxic substance used in various industrial applications. Formaldehyde exposure can cause respiratory issues and is a known carcinogen. OSHA and NIOSH set strict exposure limits, requiring employers to control formaldehyde concentrations through ventilation, personal protective equipment (PPE), and employee monitoring.
• Fit Testing. The process of verifying that a respirator fits a worker's face properly, creating an effective seal. OSHA requires fit testing for workers who must wear tight-fitting respirators to protect against inhalation of hazardous substances. Fit testing is critical for preventing exposure to airborne contaminants in hazardous environments.

G

• Gap Analysis. A method used to assess the differences between current safety performance, practices, or controls and desired or regulatory standards. In occupational safety, gap analysis helps organizations identify areas where safety programs, training, or equipment may fall short, guiding improvements to enhance workplace safety and compliance.
• Gases. Substances that exist in a gaseous state at room temperature and pressure, which can present various health and safety risks, such as toxicity, flammability, or asphyxiation. In workplaces, hazardous gases are often monitored and controlled using gas detection systems, proper ventilation, and personal protective equipment (PPE) to prevent exposure. OSHA and NIOSH provide exposure limits and guidelines for managing gases, particularly those that pose significant health risks, like hydrogen sulfide (H2S) or carbon monoxide (CO).
• General Duty Clause. A section of the Occupational Safety and Health (OSH) Act that mandates employers to provide a work environment free from recognized hazards that are likely to cause death or serious physical harm. OSHA can issue citations to employers under the General Duty Clause if there is no specific regulation addressing a particular hazard but a recognized hazard exists. It serves as a fundamental requirement for workplace safety.
• Good Housekeeping. A safety practice that involves keeping work areas clean, organized, and free of hazards. Good housekeeping reduces slip, trip, and fall risks, minimizes fire hazards, and contributes to an overall safe work environment. OSHA recommends good housekeeping practices as part of comprehensive safety programs to prevent accidents and improve workplace efficiency.
• Good Laboratory Practices (GLP). Standards and guidelines established by regulatory agencies, including OSHA, CDC, and NIOSH, for conducting experiments and tests safely and accurately. GLP includes practices for handling chemicals, maintaining lab equipment, and implementing protocols to prevent contamination, ensure accurate results, and protect worker health.
• Good Sense. Practical judgment regarding everyday safety matters. In occupational settings, good sense emphasizes cautious, attentive behavior that aligns with safety practices, contributing to a culture of proactive hazard awareness and accident prevention. Although not a formal OSHA term, good sense is encouraged as part of situational awareness training to minimize risks.
• Ground Fault Circuit Interrupter (GFCI). A safety device designed to protect against electrical shock by quickly disconnecting a circuit when it detects an imbalance in electrical current. GFCIs are especially important in wet or damp work environments, as they can prevent serious injuries or fatalities from electric shock. OSHA mandates GFCI use in specific hazardous environments where electrocution risk is elevated.
• Guarding. A safety control measure that involves using physical barriers, enclosures, or devices to protect workers from hazardous equipment, moving parts, or dangerous areas. OSHA requires machine guarding on equipment with exposed moving parts to reduce injury risks, such as cuts, entanglements, or amputations. Proper guarding is essential for meeting OSHA machine safety requirements.
• Guidelines for Hazard Evaluation Procedures. A set of guidelines developed by organizations such as OSHA and NIOSH to help employers identify, evaluate, and control workplace hazards systematically. These guidelines support employers in implementing effective safety programs, conducting thorough hazard assessments, and making informed decisions about risk mitigation and controls.

H

• Hands-on Training. Practical instruction where individuals actively perform tasks to learn procedures, correct techniques, and safe practices. Hands-on training is widely recommended by OSHA, NIOSH, and the CDC as an effective way to reinforce safety skills, particularly for tasks that involve equipment use, handling hazardous materials, or responding to emergencies.
• Hazard. Any source of potential harm, injury, or adverse health effect on a person or persons. Hazards are categorized by OSHA and NIOSH as anything that could lead to physical, chemical, biological, ergonomic, or psychological harm in the workplace, and their identification and control are critical components of workplace safety programs.
• Hazard Analysis. The process of examining each identified hazard to assess its severity, potential for causing harm, and likelihood of occurrence. Hazard analysis helps organizations prioritize risks and determine effective control measures, and is a key part of OSHA's Job Hazard Analysis (JHA) methodology.
• Hazard Categories. Classifications of hazards based on their characteristics and nature, as defined by OSHA and NIOSH. These categories include chemical hazards (e.g., toxic substances), physical hazards (e.g., noise, radiation), biological hazards (e.g., viruses, bacteria), ergonomic hazards (e.g., repetitive motion), and psychosocial hazards (e.g., workplace stress). Categorizing hazards allows for targeted safety and health controls.
• Hazard Communication (HazCom). An OSHA-mandated program that requires employers to inform and train employees on the hazards associated with chemicals they may be exposed to at work. HazCom includes the use of labeling, Safety Data Sheets (SDS), and training to ensure that employees understand the risks and know how to protect themselves when working with hazardous materials.
• Hazard Identification. The systematic process of recognizing and documenting hazards in the workplace. This involves surveying the work environment, analyzing tasks, and consulting with employees. Hazard identification is the first step in developing control measures and is central to OSHA's safety protocols.
• Hazard Tracking. The organized approach to documenting, monitoring, and managing identified hazards to ensure they are controlled over time. Hazard tracking often includes regular inspections, updates, and verification of corrective actions, which OSHA and NIOSH recommend to maintain an ongoing record of workplace hazards.
• Hazardous Condition. A physical or environmental condition in the workplace that, if not managed, can result in injury, illness, or property damage. OSHA standards require employers to identify hazardous conditions and implement necessary controls to mitigate them. Examples include wet floors, exposed wiring, and insufficient ventilation.
• Hazardous Energy. Any form of energy–such as electrical, mechanical, hydraulic, pneumatic, or chemical–that could cause harm if released unexpectedly. OSHA's Lockout/Tagout (LOTO) standard requires controlling hazardous energy sources during equipment servicing and maintenance to prevent injuries.
• Hazardous Materials. Substances that can pose risks to health, safety, or the environment due to their chemical, physical, or biological properties. Hazardous materials include flammable, toxic, corrosive, or reactive substances, and OSHA mandates that employers follow strict storage, labeling, and handling protocols to minimize exposure risks.
• Hazardous Work Environments. Workplaces with conditions that significantly increase the risk of injury or illness, such as confined spaces, construction sites, chemical plants, and manufacturing facilities. Hazardous work environments often expose workers to multiple types of hazards. Employers should perform risk assessments, implement engineering controls, provide adequate PPE, and offer training to minimize these risks.
• Hazardous System. A system that has the potential to cause harm due to the nature of its design, operation, or the materials used. Examples include high-pressure systems, chemical processing equipment, and electrical networks. OSHA requires regular inspection and maintenance of hazardous systems to prevent accidents.
• Health and Safety Plan (HASP). A comprehensive document outlining specific safety protocols, hazard assessments, and protective measures for a workplace or project. OSHA often requires HASPs for high-risk work environments, and they include emergency response procedures, PPE requirements, and health monitoring practices to protect workers from identified hazards.
• Health Hazard Evaluation (HHE). An investigation conducted by NIOSH to assess potential health hazards in a workplace, typically in response to requests from employers, employees, or OSHA. HHEs help determine if conditions pose health risks and recommend preventive measures to reduce worker exposure to identified hazards.
• Hierarchy of Controls. A systematic approach to hazard control that prioritizes methods based on effectiveness. The hierarchy includes: 1) Elimination, 2) Substitution, 3) Engineering Controls, 4) Administrative Controls, and 5) Personal Protective Equipment (PPE). This approach helps organizations apply the most effective safety measures first and reserve PPE as a last resort.
• High-Pressure Gas and Liquid Hazards. Dangers associated with handling gases and liquids under high pressure, such as explosions or leaks. High-pressure hazards are common in chemical processing, manufacturing, and HVAC systems. Prevention includes using pressure relief valves, regular equipment inspections, safety enclosures, and thorough employee training on safe handling and emergency response procedures.
• Hot Work. Any work activity that involves the use of open flames, heat, or sparks, such as welding, cutting, or grinding. Hot work can pose fire and explosion risks, particularly in environments with flammable materials. OSHA requires hot work permits, proper ventilation, and fire prevention measures to ensure safe working conditions.
• Housekeeping. The routine practice of keeping a workspace clean, organized, and free of hazards. Good housekeeping reduces accident risks by removing potential tripping hazards, maintaining clear exits, and ensuring that tools and materials are stored safely. OSHA includes housekeeping as a key element in workplace safety and accident prevention programs.

I

• IDLH (Immediately Dangerous to Life and Health). Conditions where exposure to airborne contaminants poses an immediate threat to life, would cause irreversible or delayed adverse health effects, or would impair a worker's ability to escape from a dangerous environment. These levels are established by NIOSH and are crucial in determining safe respiratory protection in emergency situations.
• Illumination. The provision and maintenance of adequate lighting in a workplace to improve visibility, reduce the risk of accidents, and enhance productivity. OSHA has specific standards for illumination in various work environments to ensure safe and comfortable working conditions.
• Immediately Dangerous to Life and Health (IDLH). A designation for situations or environments that pose an immediate or imminent danger to life or health due to toxic exposure or hazardous conditions. Exposure to IDLH conditions can cause irreversible health effects or prevent self-rescue. Proper respiratory protection and quick response measures are required in IDLH environments.
• Imminent Danger. A situation where there is reasonable certainty that a hazard exists that could cause death or serious physical harm immediately or before it can be eliminated through regular enforcement procedures. OSHA may issue an immediate citation for imminent danger conditions, requiring employers to take swift corrective action.
• Incident. An unplanned event that could potentially lead to an accident or injury, or result in property damage or environmental harm. Incidents may include near-misses and are carefully documented and analyzed to identify root causes and prevent recurrence.
• Incident Investigation. A thorough process for examining and analyzing the circumstances and causes of an incident to identify root causes and implement corrective actions. OSHA often requires incident investigations following significant workplace incidents to ensure prevention of similar events.
• Incident Rate. A metric used to calculate the number of recordable incidents per a standard number of hours worked, typically per 100 full-time employees. Incident rates allow organizations to assess the frequency of workplace injuries and illnesses and are a key performance indicator in OSHA reporting and compliance.
• Industrial Hygiene. The science dedicated to anticipating, recognizing, evaluating, and controlling workplace conditions that may cause workers' injury or illness. Industrial hygiene professionals work to control hazards related to chemical, physical, biological, and ergonomic risks in the workplace.
• Infectious Agent. A biological agent, such as a virus, bacteria, or fungus, that can cause disease. In workplaces where infectious agents are present, OSHA and CDC guidelines are used to implement effective hazard controls, such as PPE and exposure prevention protocols, to protect employees.
• Ingestion. The process of taking substances into the body through the mouth, which can lead to health risks if hazardous materials are accidentally consumed. Industrial hygiene practices aim to minimize ingestion risks through proper hygiene and housekeeping measures.
• Inhalation. The process of breathing in airborne hazardous substances, such as dust, fumes, vapors, or gases. Respiratory protection programs and air quality monitoring are critical in controlling inhalation hazards in workplaces.
• Injection. The process by which a hazardous substance enters the body through the skin via punctures, cuts, or abrasions. Common in environments where workers handle sharp, contaminated tools or equipment, injection hazards are mitigated by using PPE and safe handling practices.
• Inspection. A systematic and regular examination of the workplace to identify unsafe conditions, potential hazards, and to ensure compliance with OSHA standards. Inspections may be performed by internal safety personnel or by OSHA inspectors as part of regulatory compliance efforts.
• Inspection Report. A formal document summarizing the findings of a workplace inspection. The report identifies hazards, notes areas of non-compliance, and recommends corrective actions. OSHA often requires these reports to ensure that employers address workplace safety concerns in a timely manner.
• Instruction. Detailed information and training provided to employees on how to perform tasks safely and efficiently. Instruction may cover proper equipment use, hazard controls, and emergency procedures, and is essential in fostering a safe work environment. OSHA requires employers to provide adequate instruction on specific hazards and controls in the workplace.
• Ionizing Radiation. Radiation with enough energy to ionize atoms, creating ions by removing tightly bound electrons. Exposure to ionizing radiation can damage living tissue and increase cancer risk, so OSHA sets exposure limits and mandates protective measures in workplaces where ionizing radiation is present.
• Isolation. A control measure that involves physically separating hazards or dangerous processes from workers to reduce exposure. Isolation techniques include using barriers, enclosures, or remote controls and are integral to effective hazard control in environments with significant risks. OSHA often emphasizes isolation as a preferred control measure within the hierarchy of controls.

J

• Job Hazard Analysis (JHA). A systematic technique used to identify the dangers associated with specific job tasks to minimize risks and reduce the likelihood of worker injury. During a JHA, each step of a task is evaluated to uncover potential hazards, and appropriate controls are established to ensure safe operations. JHAs are often reviewed and updated to reflect changes in work processes or to address newly identified risks.
• Job Safety Analysis (JSA). A process that incorporates safety and health principles into specific tasks or job operations by identifying hazards, assessing risks, and developing safe procedures. JSA involves breaking down tasks into steps, analyzing each step for potential hazards, and implementing control measures. OSHA, NIOSH, and CDC recommend JSA as a proactive approach to improve workplace safety.
• Job Safety Observation (JSO). An observational technique used to monitor workers as they perform tasks, assessing compliance with safety protocols and identifying unsafe practices. JSOs help organizations reinforce safe behaviors and identify areas where additional training or safety measures may be needed. OSHA and NIOSH encourage frequent JSOs as part of comprehensive safety programs.
• Job Exposure Matrix (JEM). A tool used to evaluate and document workers' exposure to various hazards over time, based on job title, work environment, and task specifics. JEMs are often used in health and safety research by NIOSH and CDC to assess correlations between workplace exposures and health outcomes, contributing to evidence-based hazard control strategies.
• Job Transfer Option (JTO). A safety provision allowing workers who are at risk from specific hazards to transfer to another role with lower exposure levels, helping to protect them from adverse health effects. OSHA regulations may require JTOs in certain situations, particularly where workers have developed sensitivities or health conditions related to workplace exposures.
• Just-in-Time (JIT) Training. A training approach where safety information, hazard awareness, and job-specific training are provided immediately before a task or activity is performed. JIT training is especially useful for high-risk or infrequent tasks, ensuring workers have the necessary knowledge to manage hazards safely. OSHA highlights JIT training as an effective means to reinforce safe practices in dynamic work environments.

K

• Key Control. A security measure that involves tracking and managing the use of keys to access hazardous areas, equipment, or materials. OSHA and CDC regulations emphasize key control to limit unauthorized access, especially in environments handling biohazards, hazardous chemicals, or machinery, thereby reducing the risk of unauthorized exposure and potential incidents.
• Key Hazard. A primary hazard in a workplace with the potential to cause significant harm if not properly managed. OSHA requires key hazards to be addressed in safety plans and included in training programs, so employees are aware of and prepared to control these primary risks. Key hazards often involve high-risk processes, such as confined spaces, electrical systems, or hazardous materials.
• Key Performance Indicator (KPI). A measurable value used to assess the effectiveness of an organization's safety and health programs. In OSHA compliance and safety programs, KPIs track metrics such as incident rates, hazard correction timelines, and safety training completion rates to ensure continuous improvement and identify areas needing attention.
• Kickback. A sudden and forceful recoil of equipment, such as a power tool, that can cause severe injuries. OSHA emphasizes awareness, proper tool selection, and training to manage kickback hazards, especially in industries like construction and manufacturing where power tools are frequently used.
• Kinetic Hazards. Hazards that result from motion or energy in a workplace, which could cause injuries such as cuts, bruises, fractures, or worse. OSHA standards address kinetic hazards through engineering controls, safe work practices, and protective equipment, especially in environments involving machinery or moving objects.
• Kneeling Pad. A type of personal protective equipment (PPE) designed to reduce strain on the knees during work tasks performed in a kneeling position. OSHA encourages the use of kneeling pads in ergonomic hazard control to protect workers in roles that require extended kneeling, such as maintenance, construction, and plumbing.
• Knowledge, Skills, and Abilities (KSA). The attributes required to perform a job effectively, typically used in assessing a worker's qualifications and readiness for specific tasks. In OSHA and NIOSH standards, KSAs are relevant to employee training and development, ensuring workers are well-equipped with the knowledge and skills needed to operate safely and respond to workplace hazards.
• Knowledge Transfer. The process of sharing safety knowledge, procedures, and skills between experienced and new employees to maintain continuity and improve workplace safety. OSHA and NIOSH promote knowledge transfer as part of hazard awareness training, ensuring that institutional safety knowledge is retained and reinforced over time.
• Known Hazard. A hazard that has been identified and documented, often through hazard assessments, workplace inspections, or incident reports. OSHA requires known hazards to be addressed promptly, with corrective measures implemented to prevent accidents and reduce risks. Recognizing and managing known hazards is a core component of effective hazard control programs.

L

• Laboratory Safety Standards. Regulations and guidelines designed to protect workers in laboratory environments from exposure to hazardous materials, pathogens, and chemicals. OSHA, NIOSH, and CDC have specific laboratory safety standards covering proper handling, storage, and disposal of hazardous substances, as well as required PPE and emergency procedures.
• Lagging Indicator. A metric used to measure the occurrence of past incidents, such as injuries, illnesses, or safety violations, often used to assess the effectiveness of safety programs. OSHA and NIOSH encourage using lagging indicators alongside leading indicators to provide a comprehensive view of workplace safety performance.
• Lagging Safety Indicators. Performance metrics that reflect past safety incidents, such as injury rates, lost workdays, and reported illnesses. OSHA recommends using lagging indicators along with leading indicators to assess overall workplace safety and identify areas for improvement.
• Lag Time. The delay between identifying a hazard or safety issue and taking corrective action. Reducing lag time is essential in hazard control to prevent workplace injuries and ensure rapid response to emerging risks, as recommended by OSHA and NIOSH for an effective safety management system.
• Leader. A person who guides or influences others within an organization to achieve specific goals, such as fostering a safe work environment. In the context of workplace safety, leaders play a critical role in establishing a culture of safety by modeling safe practices, promoting hazard awareness, and ensuring compliance with OSHA and CDC guidelines.
• Leadership. The act of guiding, motivating, and directing a group of people or an organization toward achieving shared objectives. In workplace safety, effective leadership involves promoting hazard identification, supporting preventive measures, and ensuring that employees adhere to OSHA, CDC, and NIOSH standards to maintain a safe and healthy work environment.
• Leading Indicator. A proactive measure used to predict and prevent potential workplace hazards by monitoring conditions, behaviors, or activities that may lead to future incidents. Leading indicators include metrics like near-miss reports, safety training attendance, and equipment inspection frequencies, which OSHA promotes as part of an effective safety program.
• Legal Obligation. A duty or responsibility enforced by law that must be carried out by individuals or organizations. In the context of OSHA, employers have a legal obligation to provide a workplace free from recognized hazards and to comply with safety and health standards. Failure to meet these obligations can lead to penalties, fines, and liability.
• Liability. The legal responsibility for one's actions or inactions, particularly in the context of workplace safety. Employers may be held liable for workplace injuries or illnesses if they fail to provide adequate safety measures in line with OSHA, NIOSH, and CDC guidelines. Liability emphasizes the importance of hazard identification, control measures, and training to prevent workplace incidents.
• Lifting Techniques. Safe methods of lifting that reduce the risk of musculoskeletal injuries. OSHA recommends training workers on proper lifting techniques, using assistive devices when necessary, and recognizing the importance of body mechanics to avoid strain and overexertion.
• Local Exhaust Ventilation (LEV). A ventilation system designed to capture and remove airborne contaminants at their source before they spread into the workplace. OSHA and CDC recommend LEV systems in environments where toxic substances, dust, or fumes are generated, as they help control exposure to hazardous substances and maintain air quality standards.
• Lockout/Tagout (LOTO). A safety procedure required by OSHA that involves isolating energy sources and securing machinery or equipment in an "off" position to protect workers during maintenance or repair activities. Lockout/Tagout procedures help prevent accidental startup and release of hazardous energy, reducing risks of injury from moving parts, electricity, or pressurized fluids.

M

• Machine Guarding. Safety devices or barriers designed to protect workers from contact with moving parts or other dangerous areas of machines. OSHA requires proper machine guarding as part of its machine safety regulations to prevent injuries such as amputations, lacerations, and crush injuries. Guards may include fixed, interlocked, or self-adjusting mechanisms depending on the equipment and hazard type.
• Materials. Substances, chemicals, or components used in the production, processing, or manufacturing of goods. OSHA and NIOSH provide guidelines on safe handling, storage, and disposal of materials, especially those that pose chemical, biological, or physical hazards. Materials used in the workplace are often accompanied by Safety Data Sheets (SDS) to inform workers of associated risks and protective measures.
• Mechanical Hazards. Hazards created by moving parts, machinery, or mechanical processes that pose risks of injury, such as cuts, crush injuries, or amputations. Mechanical hazards require control measures, including machine guarding, lockout/tagout procedures, and regular maintenance, to prevent workplace accidents and ensure compliance with OSHA standards.
• Medical Surveillance. A program of ongoing health monitoring to detect early signs of illness or injury related to workplace hazards. OSHA mandates medical surveillance for workers exposed to certain toxic substances or hazardous environments to identify and prevent work-related health issues before they become severe. Programs may include physical exams, respiratory testing, and recordkeeping to track long-term health outcomes.
• Mental Health Risks. Psychological hazards in the workplace that can affect employee well-being, such as stress, fatigue, or harassment. Both OSHA and the CDC recognize the importance of addressing mental health risks through supportive work policies, stress management programs, and access to mental health resources to improve overall worker safety and productivity.
• Metals. Elements or alloys that are typically hard, conductive, and malleable, often used in manufacturing and construction. Metals such as lead, cadmium, and mercury can pose health risks through inhalation, ingestion, or skin contact, especially if workers are exposed to metal dust, fumes, or shavings. OSHA and NIOSH recommend exposure limits, proper ventilation, and PPE for handling hazardous metals.
• Mind-Mapping. A visual tool that organizes information, often used to explore multiple aspects of a topic or issue. In hazard identification and control, mind mapping can help in brainstorming potential hazards, sources, and mitigation strategies, providing a structured approach to comprehensive risk assessment.
• Mist. Tiny liquid droplets suspended in the air, often resulting from spraying or atomization processes. Certain types of mists, such as oil or chemical mists, can pose inhalation hazards. OSHA provides exposure limits and recommends ventilation and respiratory protection to reduce inhalation risks associated with toxic mists.
• Monitoring. The systematic process of observing and measuring workplace conditions to identify potential hazards and ensure compliance with health and safety standards. OSHA requires monitoring of hazards such as noise, air quality, and radiation, often using specific instruments to measure exposure levels. Regular monitoring helps detect changes in the work environment and guides the implementation of control measures.
• Motivation. The internal drive or external incentives that influence individuals to take action, such as following safety protocols or participating in training. OSHA emphasizes the role of motivation in fostering a positive safety culture, where workers are encouraged and incentivized to engage in safe practices, report hazards, and participate in safety programs.
• Musculoskeletal Disorders (MSDs). Injuries or disorders affecting the muscles, nerves, tendons, joints, or cartilage, often caused by repetitive motions, poor ergonomics, or heavy lifting. OSHA and NIOSH emphasize ergonomic assessments and preventive practices to reduce MSD risks, which are common in various industries and can lead to chronic pain or mobility issues.

N

• Near Miss. An unplanned event that could have resulted in injury, illness, or property damage but did not due to timely intervention or good fortune. Near misses are critical in hazard identification, as analyzing them provides valuable insight into workplace risks. OSHA encourages employers to track and investigate near misses to improve safety practices and prevent future incidents.
• Needlestick Injury. An injury involving puncture of the skin by a needle or other sharp medical instrument, which poses a risk of exposure to bloodborne pathogens such as hepatitis B, hepatitis C, and HIV. OSHA's Bloodborne Pathogens Standard outlines requirements to prevent needlestick injuries, including the use of engineering controls, safer needle devices, and proper training for healthcare workers.
• NIOSH Certified. A designation given to products, particularly respiratory protective equipment, that meet NIOSH's rigorous testing and certification standards. NIOSH-certified equipment, such as N95 respirators, is essential for protecting workers from airborne hazards. OSHA often requires the use of NIOSH-certified PPE in industries where respiratory protection is necessary.
• NIOSH (National Institute for Occupational Safety and Health). A federal agency responsible for conducting research and making recommendations for the prevention of work-related injuries and illnesses. NIOSH is part of the CDC and provides essential guidelines, standards, and training resources to improve workplace safety and health. NIOSH collaborates closely with OSHA in setting exposure limits and developing safety protocols.
• Nitrosamines. Chemical compounds, some of which are carcinogenic, that may be found in certain industrial environments, especially where rubber or chemical manufacturing occurs. OSHA and NIOSH recommend control measures, including ventilation and PPE, to reduce worker exposure to nitrosamines and other potentially harmful chemicals.
• Noise. Unwanted or disruptive sound that can interfere with normal work activities, concentration, and communication. Prolonged exposure to high levels of noise can lead to hearing loss and stress-related health issues. OSHA has established permissible noise exposure limits to help protect workers from harmful noise levels, and NIOSH provides additional recommendations for noise control and hearing conservation.
• Noise Exposure. The degree or duration of exposure to sound levels that could potentially cause hearing loss, stress, or other health problems. OSHA requires employers to implement hearing conservation programs for workers exposed to noise levels above 85 decibels (dB) over an 8-hour workday, with NIOSH recommending even more stringent limits. Regular monitoring, PPE, and engineering controls are part of effective noise management strategies.
• Noise-Induced Hearing Loss (NIHL). A permanent hearing impairment resulting from prolonged exposure to high noise levels. NIHL is a significant occupational health risk, and OSHA mandates noise monitoring, hearing conservation programs, and the use of protective equipment to help prevent it. NIOSH also provides guidelines for minimizing workplace noise exposure to reduce the risk of NIHL.
• Non-Ionizing Radiation. A type of radiation with sufficient energy to move atoms within a molecule, causing them to vibrate, but lacking the energy needed to remove electrons. Examples include visible light, microwaves, radio waves, and infrared radiation. OSHA and NIOSH provide guidelines for managing exposure to non-ionizing radiation in the workplace to prevent health issues, such as eye injuries and thermal effects.
• Not Otherwise Regulated (NOR) Substances. Materials that do not fall under specific OSHA regulatory classifications but may still pose health and safety risks. OSHA and NIOSH recommend implementing risk assessments and hazard control measures for NOR substances as part of an employer's overall hazard communication and workplace safety program.

O

• Observation. The action or process of closely observing, monitoring, or assessing workplace conditions, practices, and worker behavior to identify potential hazards or compliance issues. Regular observation is a key component in hazard identification and contributes to a proactive safety culture.
• Obligation. A duty or commitment to perform a certain action, often legally required in the context of occupational safety and health. Employers have an obligation under OSHA regulations to provide a safe working environment for their employees, addressing any recognized hazards.
• Occupational Exposure Limit (OEL). The maximum amount of a substance or hazard to which a worker can be exposed over a specified period, as defined by regulatory agencies or professional organizations like OSHA, NIOSH, or ACGIH. OELs help guide hazard controls and safe work practices in industries where chemical or physical exposures are present.
• Occupational Health Surveillance. The systematic collection, analysis, and interpretation of health data related to workers' exposure to hazards. Surveillance programs help identify trends in occupational illnesses and injuries, informing strategies for hazard control and prevention. This data is essential for both OSHA and NIOSH in guiding workplace safety research and regulations.
• Occupational Injury and Illness Recording and Reporting Requirements. OSHA requirements for employers to record and report specific workplace injuries, illnesses, and fatalities. This information is documented in the OSHA 300 log and provides data on workplace safety performance, helping OSHA track trends and prioritize enforcement efforts.
• Occupational Noise Exposure. The level of sound a worker is exposed to in the workplace, which can contribute to hearing loss if not adequately controlled. OSHA and NIOSH set standards and guidelines for permissible noise exposure limits, recommending protective measures like ear protection and engineering controls for noise reduction.
• Occupational Safety and Health Act of 1970 (OSH Act). A landmark U.S. law enacted to ensure worker safety and health by mandating that employers provide safe and healthful working conditions. The OSH Act led to the establishment of OSHA and gave it authority to create, enforce, and oversee workplace safety standards.
• Occupational Safety and Health Administration (OSHA). The federal agency under the U.S. Department of Labor responsible for developing and enforcing regulations to ensure workplace safety and health. OSHA sets standards, conducts inspections, and provides training and resources to prevent workplace injuries, illnesses, and fatalities.
• Occupational Safety and Health Review Commission (OSHRC). An independent federal agency that reviews and adjudicates contested OSHA citations, penalties, and abatement orders. The OSHRC provides a forum for employers to appeal OSHA's decisions and ensures due process in enforcing safety regulations.
• Open-Ended Question. A question designed to encourage a detailed response, rather than a simple "yes" or "no." Open-ended questions are often used during accident investigations or employee interviews to gather comprehensive information about workplace conditions, potential hazards, and safety practices.
• OSHA Compliance Officer. A trained professional who conducts workplace inspections and investigations to ensure employer compliance with OSHA standards. Compliance officers assess safety conditions, document hazards, and may issue citations or recommend corrective actions if violations are identified.
• OSHA Field Operations Manual (FOM). An internal guide for OSHA compliance officers that outlines procedures for conducting inspections, investigations, and enforcement actions. The FOM provides instructions for handling various scenarios, from workplace complaints to fatality investigations, and ensures consistency in OSHA enforcement activities.
• Overexertion. A condition resulting from excessive physical effort, commonly leading to strains, sprains, or musculoskeletal injuries. Overexertion is a significant source of workplace injuries and is often mitigated by ergonomics, training on proper lifting techniques, and administrative controls to minimize repetitive or forceful activities. Physical strain from lifting, pushing, pulling, holding, carrying, or throwing heavy or large objects, which can lead to injuries like muscle strains and back injuries. Prevention includes ergonomic training, mechanical aids, and proper lifting techniques.
• Overexposure. Extended exposure to harmful energy (like noise, heat), lack of energy (such as extreme cold), or dangerous substances (e.g., toxic chemicals or harmful atmospheres), leading to potential health effects. Prevention strategies include implementing exposure limits, using PPE, and providing rest breaks or rotations.

P

• Pareto Chart. A bar graph used to identify the most significant factors contributing to a particular problem, based on the Pareto Principle. Often utilized in quality control and safety assessments, Pareto Charts help prioritize hazards, enabling focus on the most critical issues affecting workplace safety and health.
• PCBs (Polychlorinated Biphenyls). Toxic, man-made industrial chemicals historically used in electrical equipment, plastics, and lubricants. Due to their significant environmental and health risks, including carcinogenic effects, PCBs are now banned in many countries but remain a concern in contaminated sites. OSHA and EPA regulations strictly limit PCB exposure in workplaces and ensure proper handling and disposal.
• Penalty. A fine or other punishment imposed by OSHA or other regulatory bodies for non-compliance with safety and health laws and standards. Penalties serve as deterrents and encourage employers to implement corrective actions and maintain compliance with safety regulations.
• Permissible Exposure Limit (PEL). The maximum amount or concentration of a substance to which workers may be exposed under OSHA regulations. PELs are established for various hazardous substances and are legally enforceable, ensuring that exposure remains within safe levels to protect worker health.
• Personal Protective Equipment (PPE). Safety equipment worn to protect workers from hazards that can cause injuries or illnesses. PPE includes items such as helmets, gloves, goggles, respiratory protection, and protective clothing. OSHA requires employers to provide PPE when hazards cannot be controlled through engineering or administrative measures alone.
• Physical Exposure. Worker exposure to physical agents, including noise, radiation, vibration, temperature extremes, and pressure. These exposures can lead to various health conditions, and OSHA sets specific exposure limits to minimize risk. NIOSH also provides research and recommendations to reduce physical exposure hazards.
• Plastics. Synthetic materials made from polymers that are widely used across industries. Plastics can pose health risks if improperly managed, particularly if they release toxic fumes or particles during manufacturing, processing, or disposal. OSHA sets standards for managing exposure to chemicals used in plastics manufacturing to minimize health hazards.
• Post-Incident Analysis. A thorough review conducted after an accident or incident to identify root causes, contributing factors, and corrective actions. OSHA recommends post-incident analysis as part of a robust safety management system to prevent recurrence and improve hazard control measures.
• Pre-Job Briefing. A safety meeting conducted before starting a job, where workers review the task, identify potential hazards, and discuss required controls, including PPE. OSHA recommends pre-job briefings as part of hazard identification and risk control, especially for complex or high-risk tasks.
• Preventive Maintenance. Scheduled, proactive maintenance activities designed to keep equipment in optimal condition, reducing the likelihood of unplanned downtime and accidents. Preventive maintenance ensures equipment reliability and plays a key role in OSHA's standards for equipment safety, helping to minimize workplace hazards.
• Prevention through Design (PtD). A NIOSH initiative that promotes integrating safety into the design phase of tools, processes, and workspaces. PtD aims to reduce occupational injuries and illnesses by eliminating hazards before they reach the workplace, aligning with OSHA's emphasis on proactive hazard control.
• Process Hazard Analysis (PHA). A systematic assessment technique used to identify and analyze potential hazards associated with industrial processes. PHAs are required by OSHA's Process Safety Management (PSM) standard and help in developing strategies to mitigate risks in high-hazard industries, such as chemicals and petrochemicals.
• Procedure. A series of structured steps that outline how to safely complete a task or process. Procedures are integral to OSHA compliance, particularly in hazardous work environments, as they standardize safe work practices and reduce risks associated with complex tasks.
• Program. A coordinated set of activities or policies aimed at achieving specific safety and health objectives. Examples include OSHA's Voluntary Protection Programs (VPP) and the CDC's National Institute for Occupational Safety and Health (NIOSH) research programs, which help improve worker safety standards and outcomes.
• Protective Clothing. Specialized apparel designed to shield workers from physical, chemical, thermal, and biological hazards. Examples include flame-resistant suits, chemical-resistant gloves, and biohazard suits. OSHA's PPE standards outline specific requirements for protective clothing based on identified workplace hazards.
• Process Safety Management (PSM). An OSHA regulation that mandates a comprehensive approach to managing hazards associated with processes that handle highly hazardous chemicals. PSM includes requirements for hazard assessment, employee training, emergency planning, and operational controls, aiming to reduce the risks of catastrophic incidents.
• Protocol. A detailed plan or set of rules guiding how specific tasks or activities should be conducted. In workplace safety, protocols help ensure consistency and safety by providing step-by-step guidance for complex or hazardous procedures, and they are often reviewed during OSHA audits.

Q

• Qualified Person. An individual with the expertise, training, and experience to recognize and evaluate hazards and implement control measures to protect workers. OSHA requires a qualified person to be present for certain high-risk tasks, such as scaffold inspections, fall protection systems, and confined space entries. A qualified person is often involved in hazard identification and may assist in setting up protective measures.
• Quantitative Fit Testing (QNFT). A precise method used to measure the effectiveness of a respirator's fit by providing a numerical measurement of leakage into the respirator. OSHA mandates quantitative fit testing for certain respirators under the Respiratory Protection Standard to ensure that workers are adequately protected from airborne hazards, especially in environments with hazardous dusts, vapors, or gases.
• Qualitative Risk Assessment. A hazard evaluation method that identifies and assesses risks using descriptive or categorical data, such as high, medium, or low risk. This approach is often used when numerical data is unavailable or unnecessary, and it can provide an initial overview of risks that need to be controlled. OSHA and NIOSH encourage qualitative assessments as a way to establish a baseline understanding of workplace hazards, especially in smaller or lower-risk workplaces.
• Quantitative Risk Assessment (QRA). An assessment method that calculates the probability and potential consequences of hazards using statistical and numerical data. QRAs provide detailed analysis, often through models and simulations, to understand risks associated with chemical exposures, machinery, and environmental hazards. OSHA and NIOSH may use QRAs to identify high-risk areas, plan controls, and help organizations allocate resources effectively for maximum risk reduction.
• Quality Control (QC). The process of ensuring that products, equipment, and systems meet specified safety standards and function as intended. QC procedures involve regular testing, inspections, and documentation to verify that workplace materials and processes comply with safety regulations. OSHA standards may require quality control measures for items like personal protective equipment (PPE) and safety devices to ensure consistent, reliable worker protection.
• Quarantine Protocols. Procedures for isolating individuals who may have been exposed to contagious illnesses to prevent the spread of disease in the workplace. CDC and NIOSH guidelines include quarantine measures for diseases like influenza, COVID-19, and tuberculosis. OSHA references CDC guidelines for workplace safety when managing contagious diseases, including quarantine protocols to control workplace exposure and prevent outbreaks.
• Quick Take (NIOSH). A brief, concise document published by NIOSH to communicate essential safety and health information rapidly and effectively to workers and employers. Quick Takes often highlight key hazards, recent studies, or control strategies in an accessible format to support hazard awareness and immediate action in the workplace. OSHA and employers may use NIOSH Quick Takes for safety training and awareness.

R

• Radiation. The emission of energy as electromagnetic waves or subatomic particles. In the workplace, sources of radiation can include x-rays, UV rays, and radioactive materials, all of which pose significant health risks. OSHA and NIOSH set strict guidelines for controlling exposure to radiation to prevent serious health effects, including cancer and radiation sickness.
• Radiation - Ionizing and Non-Ionizing. Ionizing radiation (e.g., X-rays, gamma rays) has enough energy to alter atoms and damage living tissue, leading to potential health risks like cancer. Non-ionizing radiation (e.g., UV light, microwaves) does not alter atoms but can cause burns or eye damage. Prevention includes using lead shielding for ionizing radiation, PPE, monitoring exposure levels, and implementing barriers or signs in restricted areas.
• Recognized Hazard. Any condition or risk that is commonly acknowledged as a potential source of harm or illness in the workplace. Recognized hazards are typically identified through industry standards, government regulations (such as those from OSHA and CDC), and historical data. Employers are responsible for identifying and mitigating recognized hazards.
• Recommendation. A suggested course of action, often provided by OSHA, NIOSH, or CDC experts, to improve safety or health practices. Recommendations may stem from investigations, studies, or safety audits and aim to address or prevent hazards in the workplace. While not always legally binding, these suggestions are best practices for risk reduction.
• Recordkeeping. The process of maintaining accurate and comprehensive records of workplace incidents, injuries, illnesses, and exposures. OSHA requires certain businesses to keep records of work-related injuries and illnesses, providing data that helps track and improve workplace safety. Recordkeeping is essential for compliance and for identifying trends in hazards or injuries.
• Resins. Sticky organic substances derived from plants or synthesized chemically, used in various industrial applications, including manufacturing, coating, and adhesives. Certain resins may release hazardous fumes or dust when processed, requiring proper ventilation and PPE to prevent respiratory and skin irritation. OSHA provides guidelines for handling resins to minimize chemical exposure.
• Respiratory Protection. Measures taken to protect workers from inhaling hazardous substances, including dust, fumes, smoke, or biological contaminants. Respirators, masks, and proper ventilation are part of respiratory protection, and OSHA requires specific respiratory controls in certain industries to protect lung health and prevent occupational diseases.
• Responsibility. The obligation to perform tasks and make decisions related to safety and health in the workplace. OSHA assigns specific responsibilities to employers, such as hazard identification, risk mitigation, training, and ensuring employees have access to necessary personal protective equipment (PPE). Responsibility may also extend to employees, who must follow safety protocols and report hazards.
• Risk. The probability and potential severity of harm or loss due to exposure to a hazard. In safety management, risk is often evaluated based on both the likelihood of an incident occurring and the potential consequences. Effective risk management involves identifying, assessing, and controlling risks in compliance with OSHA and NIOSH guidelines.
• Risk Analysis. The systematic process of identifying and assessing potential hazards that could negatively impact safety or health in the workplace. Risk analysis typically involves hazard identification, risk assessment, and determining control measures. OSHA and NIOSH use risk analysis to guide policy and inform regulatory standards for hazard mitigation.
• Risk Assessment. The process of evaluating identified hazards to understand their potential impact and the probability of occurrence. Risk assessments help prioritize hazards, determine control measures, and are essential for compliance with OSHA standards. Regular risk assessments are fundamental to proactive safety management and hazard prevention.
• Risk Communication. The process of informing employees and other stakeholders about potential hazards, risks, and protective measures in the workplace. Effective risk communication includes clear signage, training sessions, and readily accessible safety data sheets (SDS), which are required under OSHA's Hazard Communication Standard.
• Root Cause. The underlying factor or reason for an accident or hazard. Identifying the root cause is crucial for preventing recurrence by addressing the source of the problem. OSHA and NIOSH emphasize root cause analysis in accident investigations to develop effective, long-term safety improvements.
• Route of Entry. The pathways by which hazardous substances can enter the body, including inhalation, ingestion, injection, and skin absorption. OSHA and NIOSH focus on identifying and controlling routes of entry to prevent occupational illnesses and injuries by using protective measures such as PPE, ventilation, and hygiene protocols.

S

• Safe Work Practices. Procedures and methods established to minimize the risk of injury, illness, or harm to workers. Safe work practices include following established safety protocols, using personal protective equipment (PPE), and adhering to training guidelines to promote a safe workplace.
• Safety Audit. A systematic review conducted to evaluate the effectiveness of workplace safety programs, procedures, and policies. Safety audits help identify compliance gaps with OSHA and CDC standards, allowing for improvements to ensure a safer work environment.
• Safety Committee. A team consisting of employees and management representatives who meet regularly to identify and discuss safety concerns, review incident reports, and recommend corrective actions. Safety committees play a critical role in fostering a culture of safety and ensuring ongoing hazard identification and control efforts.
• Safety Data Sheet (SDS). A document that provides critical information about hazardous chemicals, including their properties, health effects, handling and storage requirements, and emergency measures. SDSs are required by OSHA's Hazard Communication Standard and are essential for worker safety and hazard communication.
• Safety Instruction Signs. Visual signs displayed in the workplace to provide specific safety-related instructions, such as mandatory PPE, caution about potential hazards, or reminders of safe work procedures. Safety instruction signs are a key part of OSHA's hazard communication requirements.
• Safety Manager. An individual responsible for planning, implementing, and overseeing safety programs to comply with OSHA and CDC regulations. The safety manager ensures training, hazard assessments, and incident investigations are conducted to minimize workplace injuries and illnesses.
• Safety Officer. A designated employee tasked with enforcing workplace safety standards, conducting inspections, and managing safety training. Safety officers work closely with OSHA compliance officers and ensure the organization follows federal and state safety regulations.
• Safety Professional. An expert in occupational health and safety who evaluates workplace environments, develops safety protocols, and works to prevent workplace accidents, injuries, and illnesses. Safety professionals are often certified through organizations like OSHA, NIOSH, or the Board of Certified Safety Professionals.
• Safety Technician. A trained specialist who assists in the implementation of safety policies, conducts inspections, and monitors workplace compliance with safety regulations. Safety technicians often conduct hazard assessments, safety testing, and monitor control measures as part of OSHA-mandated safety programs.
• Severity. The level or extent of harm that could result from a hazard, typically classified as minor, moderate, or severe. Severity is a key factor in risk assessment and helps prioritize control measures to mitigate high-risk hazards.
• Solids. Materials that are not liquid or gaseous and that retain a fixed shape. In workplaces, solids may include substances that can become airborne as dust, posing inhalation hazards, or that may require specific handling protocols to prevent injuries.
• Solvents. Liquids used to dissolve other substances, often in cleaning or manufacturing processes. Solvents can pose health risks, such as skin and respiratory irritation, and some are flammable or toxic. OSHA and NIOSH provide guidelines on handling, storing, and using solvents to protect worker health.
• Sound. Vibrations transmitted through air, water, or other media, detectable by the human ear. Prolonged exposure to high noise levels can result in hearing loss, making sound measurement and noise control essential in industrial environments per OSHA and NIOSH noise exposure standards.
• Standard Operating Procedures (SOPs). Written instructions that describe in detail how to perform specific tasks safely and efficiently. SOPs are designed to ensure consistency, compliance, and hazard control by providing step-by-step guidance to workers. They are essential for OSHA compliance and risk reduction in hazardous operations.
• Stress. A physical, mental, or emotional response to challenging conditions that can affect workplace safety and productivity. Chronic workplace stress may increase the risk of accidents and health issues, making stress management an essential part of workplace safety programs recommended by OSHA and the CDC.
• Struck-against Accident. An incident in which a person forcefully strikes an object, generating the force themselves. This can happen when workers accidentally walk or bump into fixed objects. Prevention measures include clear pathways, proper lighting, and awareness training for employees.
• Struck-by Accident. An incident where an object forcefully hits a person, with the object exerting the force. Common in environments where moving equipment, falling tools, or vehicles are present, struck-by accidents often result in severe injuries. Prevention strategies include proper tool lanyards, hard hats, and maintaining safe distances from moving objects.
• Substitution. A control strategy where hazardous materials or processes are replaced with safer alternatives. Examples include using water-based paints instead of solvent-based ones or substituting a less toxic chemical in place of a harmful one. Substitution is prioritized after elimination and before implementing engineering controls and is often used to reduce chemical hazards.
• Supervisor. An individual responsible for overseeing and directing the work of others, ensuring tasks are performed safely and efficiently. Supervisors play a critical role in enforcing safety protocols and reporting hazards, and they must be trained in OSHA-required safety practices.
• Supervision. The act of overseeing workers and processes to ensure that work is performed according to safety protocols. Effective supervision is essential for enforcing safety rules and promptly addressing hazards in compliance with OSHA guidelines.
• Surface Cause. An immediate or visible reason for an incident or problem, often addressed first during an investigation. Surface causes differ from root causes, which are deeper underlying factors. Identifying and addressing both types of causes is critical for comprehensive hazard prevention per OSHA and NIOSH investigation guidelines.
• System. A set of connected parts or procedures that function together within a workplace to support processes, safety, and productivity. Systems, such as safety management systems, are structured to identify, manage, and control risks, ensuring regulatory compliance and hazard prevention.
• System Improvement. Enhancements made to a system, such as a safety management system, to increase its effectiveness, safety, and efficiency. System improvements are often implemented based on OSHA recommendations or incident findings to address identified gaps or risks.

T

• Task Hazard Analysis (THA). A safety assessment method used to evaluate potential hazards associated with specific tasks or job activities. Similar to Job Safety Analysis, THA breaks down each step of a task to identify hazards and implement control measures, enhancing safety and reducing risk in OSHA-regulated environments.
• Technical Feasibility. The practicality of implementing a specific technical solution or control measure effectively in a given work environment. In occupational safety, technical feasibility assesses whether proposed safety controls (e.g., engineering controls, ventilation systems) can realistically be applied to minimize risks and ensure compliance with OSHA standards.
• Temperature. The degree of heat present in a substance, object, or environment, which can influence health and safety risks, such as heat stress, heat exhaustion, and burns. OSHA and NIOSH have established guidelines and recommendations for managing temperature in the workplace to prevent heat-related illnesses and injuries, particularly in high-temperature environments.
• Temperature Extremes. Hazardous conditions where workers are exposed to extreme heat or cold, leading to health issues such as heatstroke, hypothermia, and frostbite. Prevention includes using climate-controlled environments, providing PPE like insulated clothing or cooling vests, encouraging hydration, and scheduling breaks for workers to acclimate or warm up. Worker training on recognizing symptoms of temperature-related illnesses is essential.
• Threshold Limit Value (TLV). A guideline developed by the American Conference of Governmental Industrial Hygienists (ACGIH) that indicates the level of exposure to a substance below which most workers can be repeatedly exposed without adverse health effects. Although not legally enforceable, TLVs are often referenced by OSHA and NIOSH for hazard assessment and establishing safe exposure limits.
• Time-Weighted Average (TWA). The average exposure to a particular hazard or chemical over a specified period, typically an 8-hour workday or 40-hour workweek. OSHA and NIOSH use TWAs to establish permissible exposure limits (PELs) and recommended exposure limits (RELs), helping to protect workers from prolonged exposure to harmful substances.
• Total Worker Health (TWH). A NIOSH initiative that emphasizes policies, programs, and practices that integrate workplace safety with overall worker health and well-being. TWH focuses on eliminating occupational hazards while promoting holistic health, mental wellness, and work-life balance, making it a proactive approach to both health and safety.
• Toxins. Harmful substances that can cause adverse health effects when inhaled, ingested, or absorbed. Toxins include various chemicals, poisons, and pollutants that can result in poisoning or chronic health issues. Preventive measures include using adequate ventilation, labeling and handling instructions, PPE, and training workers on hazard recognition and safe handling of toxic substances.
• Toxicology. The scientific study of the effects of chemicals, physical agents, and biological agents on living organisms. OSHA, NIOSH, and CDC use toxicology data to establish safety standards, permissible exposure limits, and guidelines to protect workers from harmful substances in the workplace. Toxicology plays a key role in hazard identification and risk assessment.
• Training Requirements. OSHA-mandated instructions and information provided to workers to help them understand job hazards, safe work practices, and emergency procedures. Training is an essential component of hazard control and hazard communication, ensuring workers are prepared to safely handle workplace risks and comply with OSHA standards.
• Transmission-Based Precautions. Additional CDC-recommended infection control practices used in conjunction with standard precautions to prevent the spread of contagious diseases. These include contact, droplet, and airborne precautions, and are commonly applied in healthcare and laboratory settings to protect workers from occupational exposure to infectious agents.
• Two-Way Communication. A method of communication where information is exchanged between parties in both directions, encouraging interaction and feedback. OSHA promotes two-way communication in hazard communication programs, where employees are encouraged to report hazards and provide feedback on safety practices. Effective two-way communication is essential for establishing a safe workplace culture.

U

• Ultraviolet Radiation (UV). A type of electromagnetic radiation with wavelengths shorter than visible light but longer than X-rays. Exposure to UV radiation, especially in outdoor or welding-related occupations, can lead to skin cancer, eye damage (such as cataracts), and immune suppression. OSHA, NIOSH, and CDC emphasize protective measures, such as UV-blocking PPE and limiting exposure duration, to mitigate health risks associated with UV radiation.
• Uncontrolled Hazard. A hazard that has not been mitigated, isolated, or otherwise managed to reduce risk. Examples include exposed electrical wires, unguarded machinery, and hazardous chemical spills. OSHA mandates that employers identify and control such hazards through engineering controls, administrative controls, and PPE to protect workers.
• Underreporting. The failure to report or accurately document workplace injuries, illnesses, or safety hazards. Underreporting is a serious issue that can hinder OSHA's ability to ensure safe work environments. NIOSH and OSHA emphasize the importance of accurate reporting for tracking safety trends and implementing targeted interventions to improve worker health and safety.
• Universal Precautions. An infection control approach established by the CDC in which all human blood and certain bodily fluids are treated as potentially infectious. This approach is essential in healthcare, laboratory, and emergency response settings to prevent the spread of bloodborne pathogens. OSHA's Bloodborne Pathogens Standard requires employers to train workers on universal precautions and provide necessary PPE.
• Unplanned Event. An unexpected incident that disrupts normal operations and may lead to injury, illness, or property damage. Examples include equipment failures, chemical spills, or fires. OSHA encourages employers to have emergency response plans and conduct accident investigations to analyze causes and prevent recurrence.
• Unsafe Practice. Any action, behavior, or procedural lapse that increases the likelihood of an accident, injury, or health hazard in the workplace. Examples include bypassing machine guards, not wearing PPE, or failing to follow safety protocols. OSHA mandates that employers identify and correct unsafe practices through safety training, hazard assessments, and adherence to safety standards.
• Unsafe Work Practices. Actions or behaviors that increase the risk of accidents and injuries, such as ignoring safety protocols, bypassing machine guards, and rushing tasks. Prevention includes establishing strict safety policies, conducting regular safety training, monitoring for unsafe behaviors, and fostering a safety-first culture. Consistent enforcement of rules and accountability measures are essential to minimize risks.
• Upper Exposure Limit (UEL). The highest concentration of a hazardous substance in the air at which it will combust or explode if an ignition source is present. The UEL, often listed on Safety Data Sheets (SDS), helps workers understand the safe handling limits of flammable materials. OSHA's Hazard Communication Standard requires that UEL values are communicated to workers handling volatile chemicals.
• Use Zone. An area in the workplace designated for the safe operation of equipment or performance of tasks. The use zone must be clear of obstacles and hazards to ensure worker safety, especially around machinery or hazardous materials. OSHA's machine guarding standards and NIOSH recommendations stress maintaining safe use zones to minimize risk.

V

• Vapor Hazard. The potential risk associated with inhaling harmful vapors produced by volatile substances such as chemicals, solvents, or fuels. OSHA and NIOSH recommend engineering controls, such as ventilation, and personal protective equipment to reduce exposure to vapor hazards, especially in confined or poorly ventilated spaces. Vapor hazard assessments are crucial to preventing respiratory and health issues among workers.
• Ventilation. A control method used to manage air quality and reduce exposure to airborne hazards by moving fresh air into a work area and exhausting contaminated air. Ventilation systems are essential in workplaces where chemical vapors, dust, or fumes are present. OSHA and NIOSH set standards for ventilation requirements to prevent respiratory illnesses and maintain safe air quality.
• Verification. The process of confirming that safety controls, protocols, and procedures are functioning as intended. OSHA and NIOSH encourage verification through regular audits, inspections, and testing of hazard control systems, such as personal protective equipment (PPE) and ventilation. Verification is critical for ensuring continuous compliance and effective risk reduction.
• Vibration and Noise. Physical hazards from excessive vibration or noise levels, which can lead to hearing loss or musculoskeletal issues like Hand-Arm Vibration Syndrome (HAVS). Common sources include power tools, heavy equipment, and industrial machinery. Prevention includes using dampening materials, isolating sources of vibration, limiting exposure time, and providing hearing protection like earplugs or earmuffs.
• Violation. The act of disregarding or failing to comply with established rules, regulations, or laws, particularly related to workplace safety. OSHA identifies violations during inspections or accident investigations, which can result in fines or corrective actions. Common types of violations include serious, willful, and repeated violations, each with different levels of penalties based on the severity and recurrence of the offense.
• Visual Warnings. Safety alerts that use visual elements–such as signs, labels, flashing lights, and color-coded indicators–to inform workers of potential hazards in the workplace. Visual warnings are a critical part of administrative controls in hazard identification and control, as they quickly convey danger, required actions, or safety protocols. OSHA requires clear labeling and visual indicators for specific hazards, especially for chemical storage and high-voltage areas.
• Volume. In hazard control contexts, volume refers to the quantity of a substance or material present, especially in the context of storage or containment. The volume of hazardous materials, such as chemicals or combustible dust, is often monitored as it can influence the level of risk in an environment. OSHA and NIOSH provide guidelines on permissible exposure limits (PELs) and storage volumes to reduce risk and ensure safe handling.
• Vulnerability Assessment. A systematic process used to evaluate a workplace for areas or practices that may expose workers to safety or health hazards. Vulnerability assessments help identify gaps in safety protocols and are used to develop targeted interventions. OSHA supports vulnerability assessments to create proactive, preventive safety measures tailored to specific workplace risks.

W

• Walkaround Inspection. An on-site review of workplace conditions and practices, typically conducted by supervisors, safety officers, or OSHA representatives, to identify hazards and ensure compliance with safety standards. Walkaround inspections are key to proactive hazard identification and control.
• Warning Signs. Visual indicators that alert workers to potential hazards, obstacles, or conditions requiring special attention. Warning signs are part of the hazard communication system and help reduce accidents by providing clear, visible warnings about workplace risks.
• Willful Violation. A violation in which an employer knowingly disregards a legal safety requirement or acts with indifference to worker safety. Willful violations are considered severe and can result in significant penalties, as they indicate an intentional failure to comply with OSHA standards or protect employees from harm.
• Work Practice Controls. Safe procedures and methods that employees use to reduce exposure to workplace hazards. Examples include proper lifting techniques, safe chemical handling, and ergonomic practices. Work practice controls are part of the hierarchy of controls, emphasizing behavioral modifications to mitigate risks.
• Workload. The amount of work assigned to or expected from a person or group within a given timeframe. Excessive workload can lead to stress, fatigue, and reduced attention to safety procedures, increasing the risk of workplace accidents.
• Workplace Violence. Acts of violence, including physical assault, harassment, and threats, directed toward individuals at work or on duty. OSHA provides guidelines for employers to assess, prevent, and address workplace violence to protect employees and maintain a safe working environment.

X

• X-Ray Fluorescence (XRF). A non-destructive analytical technique used to determine the elemental composition of materials. In workplace safety, XRF devices are used to detect hazardous substances, such as lead in paint, metals in dust, and other contaminants. OSHA and NIOSH recognize XRF as an effective tool in hazard identification, particularly for compliance in lead and heavy metal exposure limits.
• X-Ray Inspection. A non-destructive testing method used to assess structural integrity and identify defects in materials such as welds, pipes, and other critical components. OSHA and NIOSH recommend X-ray inspection for identifying material failures that could pose workplace hazards, ensuring equipment meets safety standards to prevent accidents.
• Xenobiotic Exposure. Exposure to foreign chemical substances not naturally produced by the body, including industrial chemicals and pollutants. The CDC and NIOSH provide guidelines for managing xenobiotic exposure, which is important in hazard identification and control, particularly for chemical exposures in manufacturing, laboratories, and hazardous waste sites.
• Xenon Detection. The process of detecting xenon gas, an inert gas used in some industrial processes and in medical imaging. Although generally considered non-toxic, xenon displaces oxygen, posing an asphyxiation risk in confined spaces. OSHA recommends hazard identification and control measures for oxygen-displacing gases like xenon to protect workers in enclosed areas, with monitoring and ventilation as key safety protocols.
• Xylene. A flammable hydrocarbon solvent commonly found in paints, varnishes, and certain industrial processes. Xylene exposure poses health risks, such as respiratory irritation, headaches, and dizziness. OSHA and NIOSH provide exposure limits and recommend control measures, including adequate ventilation, respiratory protection, and hazard communication, to minimize health risks associated with xylene in the workplace.
• X-Linked Genetic Disorders. Genetic conditions associated with mutations on the X chromosome, which can influence susceptibility to occupational illnesses from certain chemical or environmental exposures. While not directly regulated by OSHA, NIOSH and the CDC provide resources on worker health considerations for genetic factors that might impact vulnerability to hazardous exposures, helping employers understand personalized health risks and implement relevant control measures.

Y

• Yellow Tag. A tagging system used to indicate equipment that may have safety issues but is still usable under certain restrictions. This form of hazard identification allows workers and inspectors to know that an item has been flagged for issues and may require attention or monitoring. Yellow tags are part of hazard control measures in environments regulated by OSHA, ensuring that potentially hazardous equipment is clearly marked to prevent misuse or accidental operation.
• Yield Point. The stress level at which a material begins to deform permanently. Understanding the yield point of materials used in workplace equipment is important for hazard identification, as equipment failure due to stress can pose significant safety risks. OSHA and NIOSH emphasize that materials should be evaluated for their yield points to prevent accidents related to structural failure.
• Yield Strength. A measure of the maximum stress a material can withstand without experiencing permanent deformation. Yield strength is critical for identifying potential hazards in equipment and structural materials, as failure to meet required strength standards can lead to accidents. OSHA and NIOSH recommend that employers assess yield strength during equipment inspections to ensure material integrity under expected work conditions.
• Young Worker Safety. A set of guidelines and resources provided by OSHA and NIOSH aimed at protecting young workers, who are often at higher risk of accidents due to lack of experience and training. These guidelines focus on hazard identification, providing young workers with adequate training, supervision, and information on their rights. Young worker safety programs highlight common hazards and controls specific to industries where young employees are frequently hired.

Z

• Zero Accident Vision (ZAV). A proactive safety philosophy and organizational goal that aims to eliminate all workplace accidents by fostering a strong safety culture, promoting hazard awareness, and implementing effective controls. ZAV encourages continuous improvement and risk management, prioritizing hazard elimination and employee engagement.
• Zero Energy State. The condition achieved by fully disconnecting and de-energizing machinery or equipment to ensure that all energy sources are effectively isolated before maintenance or repair. Reaching a zero energy state is critical for Lockout/Tagout (LOTO) procedures and is regulated by OSHA to protect workers from accidental energization or hazardous energy release.
• Zero Incident Policy. A commitment by an organization to prevent all workplace incidents, injuries, and illnesses. This policy aligns with OSHA and NIOSH recommendations for comprehensive hazard control measures, including routine hazard assessments, employee training, and adherence to safety protocols. The zero incident policy is supported by establishing clear safety goals, regular inspections, and continuous safety improvements.
• Zero Tolerance Policy. A strict organizational policy that enforces a no-compromise approach to safety violations or unsafe practices. Often applied to behaviors that increase hazards, such as substance misuse or improper use of PPE, zero tolerance policies support OSHA's emphasis on hazard control by ensuring that workplace rules and safety protocols are consistently upheld to reduce risks.
• Zone Classification. The process of categorizing work areas based on the presence and level of hazardous materials, such as flammable gases or combustible dust, to implement appropriate control measures. OSHA and NIOSH recommend zone classification to ensure that areas with higher risk are subject to more stringent safety protocols, like explosion-proof equipment or restricted access. Zone classification helps guide hazard control and align operations with OSHA standards for hazardous work environments.
• Zone of Safety. An area designated to protect workers from exposure to potential hazards during high-risk tasks. Creating a zone of safety involves implementing physical barriers, signage, or restricted entry to control worker proximity to hazardous operations. OSHA and NIOSH encourage zone of safety practices in construction, manufacturing, and chemical processing settings to minimize exposure risks.
• Zone Isolation. A hazard control practice that involves isolating specific zones within a work area to prevent the spread of contaminants, such as hazardous chemicals or biological agents. Zone isolation helps protect workers by containing hazards in a limited area, aligning with CDC guidelines for workplace health and OSHA standards for exposure control.