Hierarchy of hazard controls

Hierarchy of hazard control is a system used in industry to prioritize possible interventions to minimize or eliminate exposure to hazards. It is a widely accepted system promoted by numerous safety organizations. This concept is taught to managers in industry, to be promoted as standard practice in the workplace. It has also been used to inform public policy, in fields such as road safety. Various illustrations are used to depict this system, most commonly a triangle.

The hazard controls in the hierarchy are, in order of decreasing priority:

• Elimination
• Substitution
• Engineering controls
• Administrative controls
• Personal protective equipment

The priority should not be confused with effectiveness. The system is not based on evidence about effectiveness but based on the assumed burden on workers. If elimination of the hazard is possible, it frees workers of being aware of the hazard and protecting themselves. That is the basis for the priority. Substitution has less priority than elimination because the substitute can possibly also come with a hazard. Engineering controls depend on a well-functioning system and human behaviour. Administrative controls and personal protective equipment are always dependent on human behaviour which makes these controls less reliable.