Once the hazards have been identified, the risk need to be assessed. This include determining:

Who will be affected and how?

• How severe is the harm likely to be? (extreme, high, moderate, and low).
• How likely is it to happen? (very likely, likely, moderate, unlikely and rare).

Remember that your duty of care is extended to anyone at your workplace, even though they do not work for you or with you. People who could be harmed include employees, contractors, customers, visitors or members of the public.

After going through the risk assessment process you might find that some of the risks have been dealt with previously but need further control measures. The purpose of this step is to reduce any remaining residual risk. Use the Risk Assessment Matrix below to help establish whether the residual risk is extreme, high, medium or low. Assess the situation to estimate whether those risks are likely to happen. Where high-risk activities have been identified, action should be taken immediately. 

Risk Matrix, by WorkSafe

Remember that you should record this step. This means writing down the significant hazards and conclusions. You may use the Hazardous substances compliance tools for an assessment on hazardous substances.