Hierarchy of risk control why is it important, what does it mean?

Two of the non-negotiables for ensuring the successful management of health and safety are:

• Doing what is reasonably practicable in the circumstances (see related article); and
• Using the hierarchy of risk control to eliminate or minimise/reduce the likelihood of harm.

Both non-negotiables come together throughout Work Health and Safety (WHS) and Occupational Health and Safety (OHS) legislation. The basic premise is that a duty holder must eliminate or minimise (a WHS requirement) or eliminate or reduce (an OHS requirement) to a level that is reasonably practicable in the circumstances.

The hierarchy of control merely expands on the minimise or reduce option if a hazard or risk cannot be eliminated, so far as is reasonably practicable. The higher up the hierarchy you go, the safer you should be theoretically. The diagram below helps explain and visualise the hierarchy of risk control and demonstrates the level of health and safety protection (highest to lowest) and reliability (most to least) of control measures.

• Level 1 - eliminates the hazard so there is no longer a risk to people.
• Level 2 - changes the hazard to minimise (or reduce) the risk to people.
• Level 3 - changes the way that people work with the hazard and risk, as such it is the least effective, for example when using personal protective equipment, the hazard itself remains unchanged.

In most organisations there will be a combination of the above risk controls depending on the nature of the hazard and associated risks.

Note; that some health and safety legislative requirements may feature a specific hierarchy of control to control the specific hazards and risks (e.g. Victorian OHS Regulations Part 3.3 Prevention of falls).

Another example on this obligation is clearly demonstrated in the WHS Regulations that outlines, a duty holder, in minimising risks to health and safety must implement risk control measures as described in Regulation 36.

The risk management model below gives an overview of the whole process. The hierarchy of control is step 3 and is also referred to commonly as the fix!

Useful links:

• OHS guidance

• WHS guidance

• Training