606 Hazard Communication for the Employee

Glossary

Use the keyboard function: "Ctrl F" to search for terms in this glossary

A

• Absorbed Dose: The amount of a substance that actually enters into the body, usually expressed as milligrams of substance per kilogram of body weight (mg/kg).
• ACGIH: The American Conference of Governmental Industrial Hygienists is an organization of government and academic professionals engaged in occupational safety and health programs. ACGIH establishes recommended occupational exposure limits for chemical substances and physical agents known as Threshold Limit Values; see TLV.
• Acid: A compound that undergoes dissociation in water with the formation of hydrogen ions. Acids have pH values below 7 and will neutralize bases or alkaline media. Acids will react with bases to form salts. Acids have a sour taste and with a pH in the 0 to 2 range cause severe skin and eye burns.
• Acute Dose: The amount of a substance administered or received over a very short period of time (minutes or hours), usually within 24 hours.
• Acute Toxicity: Those adverse effects occurring following oral or dermal administration of a single dose of a substance, or multiple doses given within 24 hours, or an inhalation exposure of 4 hours.
• Aerosol: Any non-refillable receptacle made of metal, glass or plastics and containing a gas compressed, liquefied or dissolved under pressure, with or without a liquid, paste or powder, and fitted with a release device allowing the contents to be ejected as solid or liquid particles in suspension in a gas, as a foam, paste or powder or in a liquid state or in a gaseous state. Aerosol includes aerosol dispensers.
• Alkali (Also referred to as a base): A compound that has the ability to neutralize an acid and form a salt. Alkali also forms a soluble soap with a fatty acid. Alkalis have pH values between 7 and 14. They are bitter in a water solution. Alkalis with pH values between 12 and 14 are considered to be corrosive (caustic) and will cause severe damage to the skin, eyes and mucous membranes. Common strong alkalis are the substance sodium and mixture potassium hydroxide.
• Allergic Reaction: An abnormal immunologic response in a person who has become hypersensitive to a specific substance. Some forms of dermatitis and asthma may be caused by allergic reactions to chemicals.
• Alloy: A metallic material, homogeneous the naked eye, consisting of two or more elements so combined that they cannot be readily separated by mechanical means. Alloys are considered to be mixtures for the purpose of classification under the GHS.
• ANSI: The American National Standards Institute is a privately funded, voluntary membership organization that identifies industrial and public needs for national consensus standards and coordinates development of such standards.
• Article: a manufactured item other than a fluid or particle: (i) which is formed to a specific shape or design during manufacture; (ii) which has end use function(s) dependent in whole or in part upon its shape or design during end use; and (iii) which under normal conditions of use does not release more than very small quantities, e.g., minute or trace amounts of a hazardous chemical (as determined under paragraph (d) of this section), and does not pose a physical hazard or health risk to employees.
• Aspiration: The entry of a liquid or solid chemical product into the trachea and lower respiratory system directly through the oral or nasal cavity, or indirectly from vomiting.
• ASTM: The American Society for Testing and Materials develops voluntary consensus standards for materials, products, systems, and services. ASTM is a resource for sampling and testing methods, information on health and safety aspects of materials, safe performance guidelines, and effects of physical agents, biological agents, and chemicals.
• Assistant Secretary: the Assistant Secretary of Labor for Occupational Safety and Health, U.S. Department of Labor, or designee.
• Autoignition Temperature: The lowest temperature at which a flammable gas or vapor-air mixture will spontaneously ignite without spark or flame. Vapors and gases will spontaneously ignite at lower temperatures as the concentration of oxygen increases in the air. The autoignition temperature may also be influenced by the presence of catalytic substances. Materials should not be heated to greater than 80% of the autoignition temperature.

B

• BCF: Bioconcentration Factor.
• Benign: Not recurrent or not tending to progress; not cancerous.
• BOD/COD: Biochemical Oxygen Demand/Chemical Oxygen Demand.
• Boiling Point (BP): The temperature at which a liquid changes to a vapor state, at a given pressure; usually expressed in degrees of Fahrenheit or Centigrade at sea level pressure (760 mm Hg or one atmosphere). Flammable materials with low boiling points generally present special fire hazards. Initial boiling point is the temperature of a liquid at which its vapor pressure is equal to the standard pressure (101.3 kPa; 14.7 psi), i.e., the first gas bubble appears.

C

• CA: Competent Authority.
• Carcinogen: Substance or a mixture of substances which induce cancer or increase its incidence. Substances and mixtures which have induced benign and malignant tumors in well- performed experimental studies on animals are considered also to be presumed or suspected human carcinogens unless there is strong evidence that the mechanism of tumor formation is not relevant for humans.
• Carcinogenicity. The potential of a substance to cause cancer in living tissue, typically assessed by studies on prolonged exposure.
• CAS: Competent Authority.
• Carcinogen: Substance or a mixture of substances which induce cancer or increase its incidence. Substances and mixtures which have induced benign and malignant tumors in well-performed experimental studies on animals are considered also to be presumed or suspected human carcinogens unless there is strong evidence that the mechanism of tumor formation is not relevant for humans.
• CAS: Chemical Abstract Service.
• CAS Number: A number assigned to a specific chemical by the Chemical Abstracts Service, an organization operated by the American Chemical Society. CAS Numbers are used internationally to identify specific chemicals or mixtures.
• CBI: Confidential Business Information.
• cc: Cubic centimeter is a volume measurement in the metric system that is equal in capacity to one milliliter (ml). One quart is approximately 946 cubic centimeters.
• CFR: Code of Federal Regulations. A collection of the regulations that have been promulgated under United States law.
• Chemical: Any substance, or mixture of substances.
• Chemical manufacturer: an employer with a workplace where chemical(s) are produced for use or distribution.
• Chemical Name: the scientific designation of a chemical in accordance with the nomenclature system developed by the International Union of Pure and Applied Chemistry (IUPAC) or the Chemical Abstracts Service (CAS) rules of nomenclature, or a name that will clearly identify the chemical for the purpose of conducting a hazard classification.
• Chronic Toxicity: Adverse effects resulting from repeated doses or exposures to a substance over a relatively prolonged period of time.
• Classification: to identify the relevant data regarding the hazards of a chemical; review those data to ascertain the hazards associated with the chemical; and decide whether the chemical will be classified as hazardous according to the definition of hazardous chemical in this section. In addition, classification for health and physical hazards includes the determination of the degree of hazard, where appropriate, by comparing the data with the criteria for health and physical hazards.
• Combustible dust: finely divided solid particles of a substance or mixture that are liable to catch fire or explode on ignition when dispersed in air or other oxidizing media.
• Commercial account: an arrangement whereby a retail distributor sells hazardous chemicals to an employer, generally in large quantities over time and/or at costs that are below the regular retail price.
• Common name: any designation or identification such as code name, code number, trade name, brand name or generic name used to identify a chemical other than by its chemical name.
• Competent authority: Any national body(ies) or authority(ies) designated or otherwise recognized as such in connection with the Globally Harmonized System of Classification and Labelling of Chemicals (GHS).
• Compressed gas: A gas which when packaged under pressure is entirely gaseous at -50C; including all gases with a critical temperature -50C.
• Contact sensitizer: A substance that will induce an allergic response following skin contact. The definition for "contact sensitizer" is equivalent to skin sensitizer.
• Container: any bag, barrel, bottle, box, can, cylinder, drum, reaction vessel, storage tank, or the like that contains a hazardous chemical. For purposes of this section, pipes or piping systems, and engines, fuel tanks, or other operating systems in a vehicle, are not considered to be containers.
• Corrosive to metal: A substance or a mixture which by chemical action will materially damage, or even destroy, metals.
• Criteria: The technical definition for the physical, health and environmental hazards.
• Critical temperature: The temperature above which a pure gas cannot be liquefied, regardless of the degree of compression.

D

• Decomposition: Breakdown of a material or substance into simpler substances by heat, chemical reaction, electrolysis, decay, or other processes.
• Dermal: Relating to the skin.
• Dermal Corrosion: see skin corrosion.
• Dermal irritation: see skin irritation.
• Designated representative: any individual or organization to whom an employee gives written authorization to exercise such employee's rights under this section. A recognized or certified collective bargaining agent shall be treated automatically as a designated representative without regard to written employee authorization.
• Director: the Director, National Institute for Occupational Safety and Health, U.S. Department of Health and Human Services, or designee.
• Distributor: a business, other than a chemical manufacturer or importer, which supplies hazardous chemicals to other distributors or to employers.
• DNA: Deoxyribonucleic acid; the molecules in the nucleus of the cell that contain genetic information.
• Dose: The amount of a substance received at one time. Dose is usually expressed as administered or absorbed dose (e.g., milligrams material/kilogram of body weight).
• Dissolved gas: A gas which when packaged under pressure is dissolved in a liquid phase solvent.
• Dissolved Gases. Gases dissolved in a solvent under pressure, such as acetylene in acetone, which are used for specialized applications and can be hazardous if released improperly.
• DOT: U.S. Department of Transportation; the federal agency that regulates transportation of chemicals and other hazardous and non-hazardous substances.

E

• EC50: The effective concentration of a substance that causes 50% of the maximum response.
• EC Number or (ECN): A reference number used by the European Communities to identify dangerous substances, in particular those registered under EINECS.
• ECOSOC: Economic and Social Council of the United Nations.
• EINECS: European Inventory of Existing Commercial Chemical Substances.
• Employee: a worker who may be exposed to hazardous chemicals under normal operating conditions or in foreseeable emergencies. Workers such as office workers or bank tellers who encounter hazardous chemicals only in non-routine, isolated instances are not covered.
• Employer: a person engaged in a business where chemicals are either used, distributed, or are produced for use or distribution, including a contractor or subcontractor.
• End Point: physical, health and environmental hazards
• Epidemiology: The branch of science concerned with the study of human disease in specific populations, in order to develop information about the causes of disease and identify preventive measures.
• ErC50: EC50 in terms of reduction of growth rate.
• EU: European Union.
• Evaporation Rate: The ratio of the time required to evaporate a measured volume of a liquid to the time required to evaporate the same volume of a reference liquid (butyl acetate, ethyl ether) under ideal test conditions. The higher the ratio, the slower the evaporation rate. The evaporation rate can be useful in evaluating the health and fire hazards of a material.
• Explosive article: An article containing one or more explosive substances.
• Explosive chemical: A solid or liquid chemical which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Pyrotechnic chemicals are included even when they do not evolve gases.
• Explosive item: An item containing one or more explosive chemicals.
• Explosive Limits: The range of concentrations of a flammable gas or vapor (percent by volume in air) in which an explosion can occur if an ignition source is present. Also see Flammable Limits, LEL, and UEL.
• Explosive substance: A solid or liquid substance (or mixture of substances) which is in itself capable by chemical reaction of producing gas at such a temperature and pressure and at such a speed as to cause damage to the surroundings. Pyrotechnic substances are included even when they do not emit gases.
• Exposure or exposed: Exposure or exposed means that an employee is subjected in the course of employment to a chemical that is a physical or health hazard, and includes potential (e.g., accidental or possible) exposure. "Subjected" in terms of health hazards includes any route of entry (e.g. inhalation, ingestion, skin contact or absorption.)
• Eye Irritants. Substances that cause reversible inflammation or irritation of the eye upon contact.
• Eye irritation: The production of changes in the eye following the application of test substance to the front surface of the eye, which are fully reversible within 21 days of application.

F

• Flammable: A material which is easily ignited and burns with extreme rapidity. The two primary measures of this physical hazard are the flashpoint and the autoignition temperature.
• Flammable gas: A gas having a flammable range with air at 20C (68F) and a standard pressure of 101.3 kPa (14.7 psi).
• Flammable liquid: A liquid having a flash point of not more than 93C. For specific information on the definition and test methods of flammable materials, refer to 29 CFR 1910.1200. Also see: Flammable Gas, Flammable Liquid, and Flammable Solid.
• Flammable solid: A solid which is readily combustible, or may cause or contribute to fire through friction.
• Flashback: Occurs when flame from a torch burns back into the tip, the torch, or the hose. It is often accompanied by a hissing or squealing sound with a smoky or sharp-pointed flame.
• Flash point: The lowest temperature (corrected to a standard pressure of 101.3 kPa) at which the application of an ignition source causes the vapors of a liquid to ignite under specified test conditions.
• Foreseeable emergency: means any potential occurrence such as, but not limited to, equipment failure, rupture of containers, or failure of control equipment which could result in an uncontrolled release of a hazardous chemical into the workplace.

G

• Gas: A substance which (i) at 50C has a vapor pressure greater than 300 kPa; or (ii) is completely gaseous at 20C at a standard pressure of 101.3 kPa.
• Gases under pressure: Gases which are contained in a receptacle at a pressure of 200 kPa (29 psi) (gauge) or more, or which are liquefied or liquefied and refrigerated. They comprise compressed gases, liquefied gases, dissolved gases and refrigerated liquefied gases.
• Genetic: Pertaining to or carried by genes; hereditary.
• Genotoxic and genotoxicity: These apply to agents or processes which alter the structure, information content, or segregation of DNA, including those which cause DNA damage by interfering with normal replication processes, or which in a non-physiological manner (temporarily) alter its replication. Positive genotoxicity test results are usually taken as indicators for mutagenic effects.
• GESAMP: The Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection of IMO/FAO/UNESCO/WMO/WHO/IAEA/UN/UNEP.
• GHS: The Globally Harmonized System of Classification and # Labeling of Chemicals.

H

• Hazard: The inherent capacity of a substance to cause an adverse effect.
• Hazard category: The division of criteria within each hazard class, e.g., oral acute toxicity includes five hazard categories and flammable liquids includes four hazard categories. These categories compare hazard severity within a hazard class and should not be taken as a comparison of hazard categories more generally.
• Hazard class: The nature of the physical, health or environmental hazard, e.g., flammable solid carcinogen, oral acute toxicity.
• Hazard not otherwise classified (HNOC): An adverse physical or health effect identified through evaluation of scientific evidence during the classification process that does not meet the specified criteria for the physical and health hazard classes addressed in this section. This does not extend coverage to adverse physical and health effects for which there is a hazard class addressed in this section, but the effect either falls below the cut-off value/concentration limit of the hazard class or is under a GHS hazard category that has not been adopted by OSHA (e.g., acute toxicity Category 5).
• Hazard statement: A statement assigned to a hazard class and category that describes the nature of the hazards of a hazardous product, including, where appropriate, the degree of hazard.
• Hazardous chemical: means any chemical which is classified as a physical hazard or a health hazard, a simple asphyxiant, combustible dust, pyrophoric gas, or hazard not otherwise classified.
• Health hazard: A chemical which is classified as posing one of the following hazardous effects: acute toxicity (any route of exposure); skin corrosion or irritation; serious eye damage or eye irritation; respiratory or skin sensitization; germ cell mutagenicity; carcinogenicity; reproductive toxicity; specific target organ toxicity (single or repeated exposure); or aspiration hazard. The criteria for determining whether a chemical is classified as a health hazard are detailed in Appendix A to 29 CFR 1910.1200 -- Health Hazard Criteria.

I

• IARC: International Agency for the Research on Cancer.
• Ignitable: A solid, liquid or compressed gas which is capable of being set afire.
• ILO: The International Agency for Research on Cancer, a component of the World Health Organization, located in Lyon, France.
• Immediate: means that the hazardous chemical will be under the control of and used only by the person who transfers it from a labeled container and only within the work shift in which it is transferred.
• Importer: means the first business with employees within the Customs Territory of the United States which receives hazardous chemicals produced in other countries for the purpose of supplying them to distributors or employers within the United States.
• IMO: International Maritime Organization.
• Inhalation: Breathing in of a substance in the form of a gas, vapor, fume, mist, or dust.
• Initial boiling point: The temperature of a liquid at which its vapor pressure is equal to the standard pressure (101.3 kPa), i.e., the first gas bubble appears.
• Intentional explosive: A chemical or item which is manufactured with a view to produce a practical explosive or pyrotechnic effect.
• In Vitro: Outside a living organism (e.g., in a test tube).
• IOMC: Inter-organization Program on the Sound Management of Chemicals.
• IPCS: International Program on Chemical Safety.
• ISO: International Standards Organization.
• IUPAC: International Union of Pure and Applied Chemistry.

J

• Job Hazard Analysis (JHA). A systematic process used to identify and evaluate workplace hazards, including those associated with chemical exposure, to ensure compliance with OSHA's Hazard Communication Program.

K

• Key Safety Data Sheet (SDS) Information. Critical details found on an SDS, such as hazard classifications, precautionary statements, and emergency contact information, required under OSHA's Hazard Communication Standard.

L

• Label: an appropriate group of written, printed or graphic information elements concerning a hazardous chemical that is affixed to, printed on, or attached to the immediate container of a hazardous chemical, or to the outside packaging.
• Label element: the specified pictogram, hazard statement, signal word and precautionary statement for each hazard class and category.
• Latency Period: The time that elapses between exposure and the first manifestations of disease or illness.
• LD50: Lethal Dose. The concentration of a chemical in air or of a chemical in water which causes the death of 50% (one half) of a group of test animals.
• Liquid: A substance or mixture which at 50C has a vapor pressure of not more than 300 kPa (3 bar), which is not completely gaseous at 20C and at a standard pressure of 101.3 kPa, and which has a melting point or initial melting point of 20C or less at a standard pressure of 101.3 kPa. A viscous substance or mixture for which a specific melting point cannot be determined shall be subjected to the ASTM D 4359-90 test; or to the test for determining fluidity (penetrometer test) prescribed in section 2.3.4 of Annex A of the European Agreement concerning the International Carriage of Dangerous Goods by Road (ADR).
• Liquefied Gases. Gases converted to liquid under pressure for storage or transport, requiring careful handling to avoid rapid expansion upon release.
• Liquefied gases - high pressure : A gas with a critical temperature between -50C and+65C.
• Liquefied gases - low pressure : A gas with a critical temperature above +65C.
• LEL or LFL: Lower Explosive Limit or Lower Flammable Limit. Lowest concentration of a substance in air (usually expressed in percent by volume) that will produce a flash or fire when an ignition source (heat, electric arc, or flame) is present. At concentrations lower than the LEL, propagation of a flame will not occur in the presence of an ignition source. Also see UEL.

M

• m3: Cubic meter; a metric measure of volume, approximately 35.3 cubic feet or 1.3 cubic yards.
• Malignant Tumor: A tumor that can invade surrounding tissues or metastasize to distant sites resulting in life-threatening consequences.
• MARPOL: International Convention for the Prevention of Pollution from Ships.
• Melting Point: The temperature at which a solid substance changes to a liquid state.
• Metabolism (biotransformation): The conversion of a chemical from one form to another within the body.
• Metabolite: A chemical produced during metabolism.
• mg/kg: Milligrams of substance per kilogram of body weight, commonly used as an expression of toxicological dose (e.g., 15 mg/kg).
• mg/m3: Milligrams per cubic meter; a unit for measuring concentrations of particulates or gases in the air (a weight per unit volume). For example, 20 mg/m3.
• milligram (mg): The most commonly used unit of measure in medicine and toxicity consisting of one thousandth of a gram (1x10-3 g).
• Mixture: a combination or a solution composed of two or more substances in which they do not react.
• ml: Milliliter; a metric unit of volume. There are 1,000 milliliters in one liter. 1 teaspoon = 5 milliliters.
• Mutagen: An agent giving rise to an increased occurrence of mutations in populations of cells and /or organisms.
• Mutagenicity. The potential of a substance to cause genetic mutations, which may lead to cancer or other genetic disorders.
• Mutation: A permanent change in the amount or structure of the genetic material in a cell. The term "mutation" applies both to heritable genetic changes that may be manifested at the phenotypic level and to the underlying DNA modifications when known (including, for example, specific base pair changes and chromosomal translocations). The terms "mutagenic" and "mutagen" are used for agents giving rise to an increased occurrence of mutations in populations of cells and/or organisms.

N

• Narcotic Effects. Depressant effects on the central nervous system, leading to symptoms such as drowsiness, dizziness, and loss of coordination.
• NFPA: The National Fire Protection Association is an international membership organization which promotes fire protection and prevention and establishes safeguards against loss of life and property by fire.
• NIOSH: The National Institute for Occupational Safety and Health is a part of the Centers for Disease Control and Prevention, U.S. Public Health Service, U.S. Department of Health and Human Services.
• NOEC: No observed effect concentration.
• NTP: The National Toxicology Program is a component of the U.S. Public Health Service. The NTP publishes the Annual Report on Carcinogens.

O

• Odor Threshold: The lowest concentration of a substance in air that can be detected by smell.
• OECD: The Organization for Economic Cooperation and Development.
• Organic peroxide: Liquid or solid organic chemical which contains the bivalent -0-0- structure and as such is considered a derivative of hydrogen peroxide, where one or both of the hydrogen atoms have been replaced by organic radicals. The term organic peroxide includes mixtures containing at least one organic peroxide. Organic peroxides are thermally unstable chemicals, which may undergo exothermic self-accelerating decomposition.
• Oxidation: A change in a chemical characterized by the loss of electrons. Oxidation is a reaction in which a substance combines with oxygen.
• Oxidizing gas: Any gas which may, generally by providing oxygen, cause or contribute to the combustion of other material more than air does. "Gases which cause or contribute to the combustion of other material more than air does" means pure gases or gas mixtures with an oxidizing power greater than 23.5% (as determined by a method specified in ISO 10156 or 10156-2; see Appendix B.4 of 29 CFR 1910.1200).
• Oxidizing liquid: A liquid which, while in itself not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material.
• Oxidizing solid: A solid which, while in itself not necessarily combustible, may, generally by yielding oxygen, cause, or contribute to, the combustion of other material.

P

• PEL: Permissible Exposure Limit. A legally enforceable occupational exposure limit established by OSHA, usually measured as an eight-hour time-weighted average, but also may be expressed as a ceiling concentration exposure limit.
• Physical hazard: means a chemical that is classified as posing one of the following hazardous effects: explosive; flammable (gases, aerosols, liquids, or solids); oxidizer (liquid, solid or gas); self-reactive; pyrophoric (liquid or solid); self-heating; organic peroxide; corrosive to metal; gas under pressure; or in contact with water emits flammable gas. See Appendix B to § 1910.1200 - Physical Hazard Criteria.
• Pictogram: a phrase that describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposure to a hazardous chemical, or improper storage or handling.
• PLHCP: means Physician or Other Licensed Health Care Professional.
• ppm: Parts per million; the proportion (by volume) of a gas or vapor per million parts of air; also the concentration of a chemical in a liquid or solid form.
• Precautionary statement: A phrase (and/or pictogram) that describes recommended measures that should be taken to minimize or prevent adverse effects resulting from exposure to a hazardous product, or improper storage or handling of a hazardous product.
• Produce: means to manufacture, process, formulate, blend, extract, generate, emit, or repackage.
• Product identifier: the name or number used for a hazardous chemical on a label or in the SDS. It provides a unique means by which the user can identify the chemical. The product identifier used shall permit cross-references to be made among the list of hazardous chemicals required in the written hazard communication program, the label and the SDS.
• Pyrophoric gas: a chemical in a gaseous state that will ignite spontaneously in air at a temperature of 130 degrees F (54.4 degrees C) or below.
• Pyrophoric liquid: A liquid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air.
• Pyrophorics. Substances that can spontaneously ignite in air at or below 55ºC (131ºF), posing serious fire hazards.
• Pyrophoric solid: A solid which, even in small quantities, is liable to ignite within five minutes after coming into contact with air.
• Pyrotechnic article: An article containing one or more pyrotechnic substances.
• Pyrotechnic chemical: A chemical designed to produce an effect by heat, light, sound, gas or smoke or a combination of these as the result of non-detonative self-sustaining exothermic chemical reactions.
• Pyrotechnic item: An item containing one or more pyrotechnic chemicals.
• Pyrotechnic substance: A substance or mixture of substances designed to produce an effect by heat, light, sound, gas or smoke or a combination of these as the result of non-detonative, self-sustaining exothermic (heat-related) chemical reactions.

Q

• QSAR: Quantitative Structure-Activity Relationships.

R

• Reactivity: A substance's susceptibility to undergo a chemical reaction or change that may result in dangerous side effects, such as an explosion, burning, and corrosive or toxic emissions.
• Readily combustible solid: Powdered, granular, or pasty substance or mixture which is dangerous if it can be easily ignited by brief contact with an ignition source, such as a burning match, and if the flame spreads rapidly.
• Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria: The latest revised edition of the United Nations publication bearing this title, and any published amendment thereto.
• Recommendations on the Transport of Dangerous Goods, Model Regulations: The latest revised edition of the United Nations publication bearing this title, and any published amendment thereto.
• Refrigerated liquefied gas: A gas which when packaged is made partially liquid because of its low temperature.
• Reproductive toxicity: This hazard includes adverse effects on sexual function and fertility in adult males and females, as well as adverse effects on development of the offspring. Some reproductive toxic effects cannot be clearly assigned to either impairment of sexual function and fertility or to developmental toxicity. Nonetheless, chemicals with these effects shall be classified as reproductive toxicants.
• Respiratory sensitizer: A chemical that will lead to hypersensitivity of the airways following inhalation of the chemical.
• Respiratory sensitization. A health effect where repeated exposure to a substance causes an allergic reaction in the respiratory system, potentially leading to asthma or other respiratory issues.
• Responsible party: means someone who can provide additional information on the hazardous chemical and appropriate emergency procedures, if necessary.
• RID: The Regulations concerning the International Carriage of Dangerous Goods by Rail [Annex 1 to Appendix B (Uniform Rules concerning the Contract for International Carriage of Goods by Rail) (CIM) of COTIF (Convention concerning international carriage by rail)], as amended.
• Risk: The probability that an adverse effect will occur.

S

• Safety Data Sheet (SDS): means written or printed material concerning a hazardous chemical that is prepared in accordance with paragraph (g) of this section.
• SAR: Structure Activity Relationship.
• Self-Accelerating Decomposition Temperature (SADT): The lowest temperature at which self-accelerating decomposition may occur with substance as packaged.
• Self-heating chemical: A solid or liquid chemical, other than a pyrophoric substance, which, by reaction with air and without energy supply, is liable to self-heat; this substance differs from a pyrophoric substance in that it will ignite only when in large amounts (kilograms) and after long periods of time (hours or days).
• Self-reactive chemical: A thermally unstable liquid or solid chemical liable to undergo a strongly exothermic decomposition even without participation of oxygen (air). This definition excludes substances or mixtures classified under the GHS as explosive, organic peroxides or as oxidizing.
• Serious eye damage: The production of tissue damage in the eye, or serious physical decay of vision, following application of a test substance to the front surface of the eye, which is not fully reversible within 21 days of application.
• Signal word: means a word used to indicate the relative level of severity of hazard and alert the reader to a potential hazard on the label. The signal words used in this section are "danger" and "warning." "Danger" is used for the more severe hazards, while "warning" is used for the less severe.
• Simple asphyxiant: means a substance or mixture that displaces oxygen in the ambient atmosphere, and can thus cause oxygen deprivation in those who are exposed, leading to unconsciousness and death.
• Skin corrosion: The production of irreversible damage to the skin; namely, visible necrosis through the epidermis and into the dermis, following the application of a test substance for up to 4 hours. Corrosive reactions are typified by ulcers, bleeding, bloody scabs, and, by the end of observation at 14 days, by discoloration due to blanching of the skin, complete areas of alopecia (baldness), and scars. Histopathology should be considered to evaluate questionable lesions.
• Skin irritation: The production of reversible damage to the skin following the application of a test substance for up to 4 hours.
• Skin sensitizer: A substance that will induce an allergic response following skin contact. The definition for skin sensitizer is equivalent to contact sensitizer.
• Specific chemical identity: means the chemical name, Chemical Abstracts Service (CAS) Registry Number, or any other information that reveals the precise chemical designation of the substance.
• Specific target organ toxicity: Single Exposure (STOT-SE). Specific target organ toxicity arising from repeated exposure to a substance or mixture. All significant health effects that can impair function, both reversible and irreversible, immediate and/or delayed and not specifically addressed in Appendices A.1 to A.7 and A.10 of 29 CFR 1910.1200 are included.
• Solid: A substance or mixture which does not meet the definitions of a liquid or gas.
• Solubility: The ability of a substance to be dissolved in a solvent. Solubility is expressed according to the solvent (e.g., solubility in water, solubility in acetone, etc.).
• SPR: Structure Property Relationship.
• STEL: Short-Term Exposure Limit (ACGIH terminology); see TLV.
• Substance: means chemical elements and their compounds in the natural state or obtained by any production process, including any additive necessary to preserve the stability of the product and any impurities deriving from the process used, but excluding any solvent which may be separated without affecting the stability of the substance or changing its composition.
• Substance which, in contact with water, emits flammable gases: A solid or liquid substance or mixture which, by interaction with water, is liable to become spontaneously flammable or to give off flammable gases in dangerous quantities.
• Supplemental label element: Any additional non-harmonized type of information supplied on the container of a hazardous product that is not required or specified under the GHS. In some cases this information may be required by other competent authorities or it may be additional information provided at the discretion of the manufacturer/distributor.
• Symbol: A graphical element intended to succinctly convey information.
• Synonym: Another name or names by which a material is known. Methyl alcohol, for example, is also known as methanol or wood alcohol.

T

• Target Organ: An organ on which a substance exerts a toxic effect.
• Target Organ Toxicity. The harmful effect of a substance on specific organs following exposure, potentially causing significant impairment to functions of the liver, kidneys, lungs, or other organs.
• Technical name: A name that is generally used in commerce, regulations and codes to identify a substance or mixture, other than the IUPAC or CAS name, and that is recognized by the scientific community. Examples of technical names include those used for complex mixtures (e.g., petroleum fractions or natural products), pesticides (e.g., ISO or ANSI systems), dyestuffs (Color Index system) and minerals.
• Teratogen: A substance that can cause malformations or alterations in the appearance or function of a developing embryo.
• TLV: Threshold Limit Value. The occupational exposure limit published by the American Conference of Governmental Industrial Hygienists (ACGIH). ACGIH expresses Threshold Limit Values in four ways:
1. TLV-TWA: The allowable Time-Weighted Average - A concentration for a normal 8- hour workday or 40-hour workweek.
2. TLV-STEL: Short-Term Exposure Limit - A maximum concentration for a continuous 15-minute exposure period (maximum of four such periods per day, with at least 60 minutes between exposure periods, and provided the daily TLV-TWA is not exceeded).
3. TLV-C: Ceiling limit: - A concentration that should not be exceeded even instantaneously.
4. TLV-Skin: - The skin designation refers to the potential contribution to the overall exposure by the cutaneous route, including mucous membranes and the eye. Exposure can be either by airborne or direct contact with the substance. This designation indicates that appropriate measures should be taken to prevent kin absorption.
• Toxic Substance: Any substance that can cause injury or illness, or which is suspected of being able to cause injury or illness under some conditions.
• Toxicity: A relative property of a chemical agent that refers to a harmful effect on some biological mechanism and the conditions under which this effect occurs.
• Trade Name: The trademark name or commercial trade name for a material or product.
• Trade Secret: means any confidential formula, pattern, process, device, information or compilation of information that is used in an employer's business, and that gives the employer an opportunity to obtain an advantage over competitors who do not know or use it. Appendix E to § 1910.1200 - Definition of Trade Secret, sets out the criteria to be used in evaluating trade secrets.
• TWA: Time-Weighted Average. The concentration of a material to which a person is exposed, averaged over the total exposure time - generally the total workday (8 to 12 hours); also see TLV.

U

• UEL or UFL: Upper explosive limit or upper flammable limit; the highest concentration of a vapor or gas (highest percentage of the substance in air) that will produce a flash of fire when an ignition source (e.g., heat, arc, or flame) is present. At higher concentrations, the mixture is too "rich" to burn. Also see LEL.
• UNCED: United Nations Conference on Environment and Development.
• UNCETDG/GHS: United Nations Committee of Experts on the Transport of Dangerous Goods and on the Globally Harmonized System of Classification and Labelling of Chemicals.
• UNITAR: United Nations Institute for Training and Research.
• UNSCEGHS: United Nations Sub-Committee of Experts on the Globally Harmonized System of Classification and Labelling of Chemicals.
• UNSCETDG: United Nations Sub-Committee of Experts on the Transport of Dangerous Goods.
• Unstable: Decomposing readily or another unwanted chemical change during normal handling or storage.
• Unstable explosive: An explosive which is thermally unstable and/or too sensitive for normal handling, transport, or use.
• Use: means to package, handle, react, emit, extract, generate as a byproduct, or transfer.

V

• Vapor density: The weight of a vapor or gas compared to the weight of an equal volume of air is an expression of the density of the vapor or gas. Materials lighter than air (e.g., acetylene, methane, hydrogen) have vapor densities less than 1.0. Materials heavier than air (e.g., propane, hydrogen sulfide, and ethane) have vapor densities greater than 1.0. All vapors and gases will mix with air, but the lighter materials will tend to rise and dissipate (unless confined). Heavier vapors and gases are likely to concentrate in low places along or under floors, in sumps, sewers, manholes, trenches, and ditches, where they may create fire or health hazards.
• Vapor pressure: Pressure exerted by a saturated vapor above its liquid in a closed container. Three facts are important to remember:
• Vapor pressure of a substance at 100 deg F will always be higher than the vapor pressure of the substance at 68 deg F (20 deg C).
• Vapor pressures reported on SDSs in millimeters of mercury (mmHg) are usually very low pressures; 760 mmHg is equivalent to 14.7 pounds per square inch (psi).
• The lower the boiling point of a substance, the higher its vapor pressure.
• Volatility: The tendency or ability of a liquid or solid material to form a gas at ordinary temperatures. Liquids such as alcohol and gasoline, because of their tendency to evaporate rapidly, are called volatile liquids.

W

• Work area: means a room or defined space in a workplace where hazardous chemicals are produced or used, and where employees are present.
• Workplace: means an establishment, job site, or project, at one geographical location containing one or more work areas.

X

• Xylene. A volatile organic compound and hazardous chemical commonly found in industrial settings, requiring proper labeling and handling under OSHA's Hazard Communication Program.

Y

• Yellow Caution Labels. Labels used to indicate physical or health hazards associated with chemicals, as mandated by OSHA's labeling requirements for hazard communication.

Z

• Zero Accident Vision. A safety philosophy aiming for the elimination of workplace accidents and injuries, often supported by robust hazard communication programs compliant with OSHA standards.