Priorities for control

Controlling exposures to hazardous substances is arguably the most important endeavour in occupational hygiene. Evaluation is important, but doesn’t directly protect worker health. There are many ways to control exposures, but some are more effective and reliable than others. One way prioritise controls is to use the following approach:

Source

First consider if it is possible to remove the process or chemical creating the risk. For example, replace methyl ethyl ketone with a less dangerous alternative such as acetone for cleaning activities. Or paint things using rollers and brushes rather than spray painting.

Controlling the source is the usually the most effective way. It fundamentally removes or reduces the inherent risk. It also does not rely on maintenance or monitoring to be effective.

Transmission

Managing transmission means recapturing the contaminant after it has been generated but before it reaches the worker. This includes local extraction ventilation and water suppression systems.

These controls can be very effective but often require specialist design (such as an engineer). Because these controls do not lower the generation rate of the contaminate, a poorly designed or maintained local extraction system may not guarantee worker protection.

Worker

Personal protective equipment is considered the last line of defence (such as respirators and ear plugs etc). They rely on the worker to fit the PPE correct every time. Incorrect use is not obvious but can negate any protection.