What is the OSHA hierarchy of hazard control?

The OSHA hierarchy of hazard control describes the order in which different injury and illness prevention methods should be used. It emphasizes engineering solutions (including elimination or substitution), followed by safe work practices, and worker protection.

It includes five levels of control: Elimination < Substitution > Engineering Controls > Administrative Controls > Personal Protective Equipment (PPE).

OSHA's hierarchy includes provisions to protect workers during foreseeable emergencies.

These could include fires and explosions, chemical releases, hazardous material spills, unplanned equipment shutdowns, infrequent maintenance activities, natural and weather disasters, workplace violence, terrorist or criminal attacks, disease outbreaks, or medical emergencies.

"Elimination" is the first step of OSHA's hazard control. The most effective way to mitigate a hazard is to eliminate it.

Some examples of elimination include:

• Reworking a process to operate at ground level to eliminate fall hazards

• Eliminating a sampling step at a hazardous location and conducting sampling elsewhere

• Removing a dangerous machine part

• Replacing a faulty tool that's a risk to workers

If the hazard cannot be removed, the next step is "Substitution." This means replacing a hazardous chemical with a less hazardous one.

If that is not possible, then the next step is to "Engineer Controls." This means focusing on isolating workers from a hazard through changes to the work environment. Engineering controls work better than administrative controls and PPE because they do not rely on employee behavior.

Examples of engineering controls include:

• Adding an overhead balancer to reduce strain on workers

• Upgrading ventilation systems and adding Plexiglas dividers to prevent COVID-19 spread

• Using an exhaust system to remove welding fumes

After dealing with immediate threats, focus on preventative measures. This stage is known as "Administrative Controls" and is aimed at changing work practices to reduce risks to workers.

Examples include changes such as:

• Staggering shifts in a plant to reduce the density of workers on the line

• Reducing exposure time for workers to a specific hazard

• Installing alarms or signage to warn employees

• Using the buddy system for confined space entry

The final line of defense is called Personal Protective Equipment, or PPE. This step relies on individual compliance.