The hierarchy of control measuresThe hierarchy of control measures

The hierarchy of control measures

Some control measures are more effective than others. Control measures can be ranked from the highest level of protection and reliability to the lowest. This ranking is known as the hierarchy of control.

You must always aim to eliminate a hazard, which is the most effective control. If this is not reasonably practicable, you must minimise the risk by one or a combination of the following:

• Substitution – for example using an excavator with a rock breaker rather than manual method
• Isolation – for example using concrete barriers to separate pedestrians and powered mobile plant to reduce the risk of collision, and
• Engineering Controls – for example benching, battering or shoring the sides of the excavation to reduce the risk of ground collapse.

If risk remains, it must be minimised by implementing administrative controls, so far as is reasonably practicable, for example by installing warning signs near the excavation.

Any remaining risk must be minimised with suitable personal protective equipment (PPE), such as providing workers with hard hats, hearing protectors and high visibility vests.

Administrative control measures and PPE rely on human behaviour and supervision and used on their own tend to be the least effective in minimising risks.

Factors that should be considered when choosing suitable control measures include:

• excavating plant - when quantities are large, it may be effective to use different types of plant for the various materials to be excavated
• stockpiling arrangements - another site may need to be found for temporary stockpiling of materials
• material placement - the methods and plant used for excavating, transporting and compacting the material should be evaluated
• dewatering equipment, if required, and the system to be used
• transport of the excavated material - the type of plant used, the length of haul, the nature of the haul route, and the conditions of tipping and/or spreading.

Chapters 4-6 of this Code provide information on control measures for excavation work.