Risk assessment

Modern occupational safety and health legislation usually demands that a risk assessment be carried out prior to making an intervention. This assessment should:
• Identify the hazards
• Identify all affected by the hazard and how
• Evaluate the risk
• Identify and prioritise the required actions
The calculation of risk is based on the likelihood or probability of the harm being realised and the severity of the consequences. This can be expressed mathematically as a quantitative assessment (by assigning low, medium and high likelihood and severity with integers and multiplying them to obtain a risk factor, or qualitatively as a description of the circumstances by which the harm could arise.
The assessment should be recorded and reviewed periodically and whenever there is a significant change to work practices. The assessment should include practical recommendations to control the risk. Once recommended controls are implemented, the risk should be re-calculated to determine of it has been lowered to an acceptable level. Generally speaking, newly introduced controls should lower risk by one level, i.e, from high to medium or from medium to low
The precautionary principle is an increasingly used method for reducing potential chemical or biological OSH risks.