A JHA is a form that represents each task of a given job, plus a description of the task, the hazards and potential hazard controls.

“A job hazard analysis is an exercise in detective work,” the agency said. The goal is to discover:

What is the hazard?(What can go wrong?)

What are the consequences?

How could it happen?

What are other contributing factors?

How likely is it that the hazard will occur?

Hazards are rarely the result of a singular cause resulting in a singular effect, OSHA said. It’s much more likely that many contributing factors line up in a certain way to create the hazard.

Additional inputs necessary when analyzing hazards include:

Environment: Where does the hazard exist?

Exposure: Who might be injured or made ill by the hazard?

Trigger: What event/events might cause the hazard to lead to an injury or illness?

Contributing factors.

Consequences: What are the possible results if an accident was to occur?

Example: A metal-shop worker clearing a snag comes into contact with a rotating pulley that pulls his hand into the machine and severs his fingers.

A JHA for this job would look like this:

What is the hazard? The worker’s hand could come into contact with a rotating object that catches it and pulls it into the machine.

What are the consequences? The worker could receive a severe injury and lose fingers or one or both hands.

How could it happen? It could happen as a result of the worker trying to clear a snag during operations or as part of a maintenance activity while the machine is operating.

What are other contributing factors? This hazard occurs very quickly. It does not give the worker much opportunity to recover or prevent it once his hand comes into contact with the pulley. “This is an important factor, because it helps you determine the severity and likelihood of an accident when selecting appropriate hazard controls,” OSHA said. Experience has shown that training is not very effective in hazard control when triggering events happen quickly because people cannot react in time.

How likely is it that the hazard will occur? If there have already been near misses or actual incidents, then the likelihood of a reoccurrence is high. The likelihood of reoccurrence is high for the example given because basic safety practices such as machine guarding to prevent contact and utilizing a lockout/tagout procedure are lacking.

Finally, a plan is drawn up for controlling each hazard associated with each task.

Using the industry standard hierarchy of hazard controls is useful for this step. The hierarchy of hazard controls are, in order of effectiveness:

Elimination.Physically removing the hazard is the most effective control.

Substitution. Substituting processes, equipment, materials or other factors to remove the hazard, such as by replacing lead-based paint with acrylic paint.

Engineering. These controls do not eliminate hazards but isolate people from them, including through the use of machine guards, blast shields and exhaust ventilation.

Administrative. These change the way people work, including using work permits, scheduling modifications, additional training, exposure limitations, alarms, signs and warning labels.

Personal protective equipment. This includes respirators, hearing protection, protective clothing, safety glasses and hardhats.