706 Conducting a Job Hazard Analysis

Engineering Controls

These controls focus on the source of the hazard, unlike other types of controls that generally focus on the employee exposed to the hazard. The basic concept behind engineering controls is that, to the extent feasible, the work environment and the job itself should be designed to eliminate hazards or reduce exposure to hazards. While this approach is called engineering control, it does not necessarily mean that an engineer is required to design the control.

Engineering controls are based on the following broad principles:

1. If feasible, design the facility, equipment, or process to remove the hazard and/or substitute something that is not hazardous or is less hazardous.
• Redesigning, changing, or substituting equipment to remove the source of excessive temperatures, noise, or pressure;
• Redesigning a process to use less toxic chemicals;
• Redesigning a work station to relieve physical stress and remove ergonomic hazards; or
• Designing general ventilation with sufficient fresh outdoor air to improve indoor air quality and generally to provide a safe, healthful atmosphere.
2. If removal is not feasible, enclose the hazard to prevent exposure in normal operations.
• Complete enclosure of moving parts of machinery;
• Complete containment of toxic liquids or gases;
• Glove box operations to enclose work with dangerous microorganisms, radioisotopes, or toxic substances; and
• Complete containment of noise, heat, or pressure-producing processes.
3. Where complete enclosure is not feasible, establish barriers or local ventilation to reduce exposure to the hazard in normal operations. Examples include:
• Ventilation hoods in laboratory work;
• Machine guarding, including electronic barriers;
• Isolation of a process in an area away from workers, except for maintenance work;
• Baffles used as noise-absorbing barriers; and
• Nuclear radiation or heat shields.

Administrative Controls

1. We use this term here to describe other measures aimed at reducing employee exposure to hazard, generally by manipulating the work schedule. Such measures include:
• Lengthened rest breaks,
• Additional relief workers,
• Exercise breaks to vary body motions, and
• Rotation of workers through different jobs
• Safe work practices
2. Administrative controls normally are used in conjunction with engineering controls that eliminate or reduce the hazard. By following established safe work practices and procedures for accomplishing a task safely (and using PPE in many cases), your employees can further reduce their exposure to hazard. Some of these general practices are very general in their applicability. They include procedural activities such as:
• Removal of tripping, blocking, and slipping hazards;
• Removal of accumulated toxic dust on surfaces; and
• Wetting down surfaces to keep toxic dust out of the air.

Personal Protective Equipment (PPE)

When exposure to hazards cannot be engineered completely out of normal operations or maintenance work, and when safe work practices and administrative controls cannot provide sufficient additional protection from exposure, personal protective clothing and/or equipment may be required.

PPE includes such items as: