La hiérarchie des contrôles Copy

The Hierarchy of Controls

Once an HRA and Hygiene Survey has been done, the employer then knows where the visual risks are, what eye hazards are prevalent in which areas and who is exposed8,9. Focus now needs to be on how to prevent exposure, control it and train the employees on the risk and consequences of exposure.

Where occupational exposure limits exist for chemicals, dusts and radiation which affect eyes employers have the added responsibility to reduce the risk of health effects due to exposure by implementing the “Hierarchy of Hazard Controls”8. The hierarchy of controls are defined as a system for controlling risks in the workplace. It is a step-by-step approach to eliminating or reducing risks. The system ranks risk controls from the highest level of protection and reliability down to the lowest and least reliable protection method.

Figure 5.4: The Hierarchy of Control Measures


The Hierarchy of Controls are elimination, substitution, engineering controls, administrative controls, and personal protective equipment8,9.

Elimination – Physically remove the hazard

The elimination of a visual or ocular risk is the most effective way to prevent risks to workers.  An example of a visual hazard elimination may include removing the cause of flying debris, such as falling objects. This can be accomplished by correcting conditions that cause the objects to fall (i.e. more frequent clean-ups, guards to prevent objects from falling from conveyors, etc.).

Substitution – Replace the hazard15

Substitution for visual hazards can be challenging, but with some creativity, it can be achieved. For example, substitute the more harmful or hazardous chemicals with those that pose less of a risk.

Engineering controls – Isolate people from the hazard17,21

For example, a grinding operation that creates flying debris and dust can be placed in a glove box. This will contain the debris, but it has limits due to manufactured part sizes. Other engineering controls may include isolation from the hazard, such as the separation of employees from laser beams.

Administrative controls – Change the way people work16

Administrative controls include training, procedures, policies, or shift designs. These are intended to change the behaviour of employees rather than removing the hazard. Limiting the time of exposure, reducing shifts, rotating workers are all examples of administrative controls.

Personal protective equipment– Protect the worker with PPE19

PPE for vision and eye protection consists of goggles, masks, visors, and shields. Workers who are regularly exposed to eye hazards must be provided with PPE by the employers for free.

Administrative controls and PPE are frequently used with existing processes where hazards are not particularly well controlled. Administrative controls and PPE programs may be relatively inexpensive to establish but, over the long term, can be very costly to sustain. These methods for protecting workers have also proven to be less effective than other measures, requiring significant effort by the affected workers.