When performing a risk assessment, what quantitative metric is used to determine the acceptability of a potential hazard?

When performing a risk assessment, the quantitative metric used to determine the acceptability of a potential hazard is the risk level, which is typically calculated as a function of the probability of occurrence and the severity of the potential harm. While the specific formulas and scales used to quantify risk may vary depending on the applicable standards and the organization's risk assessment methodology, the general principle remains the same: higher probability and severity result in a higher risk level. The risk level is often expressed as a numerical score or categorized into risk bands, such as 'low,' 'medium,' or 'high.' Organizations typically define acceptable risk levels based on their risk tolerance and legal requirements. If the calculated risk level exceeds the acceptable threshold, additional safety measures must be implemented to reduce either the probability of occurrence or the severity of harm until the risk level falls within the acceptable range. For example, if a hazard is identified as having a high probability of causing serious injury, resulting in a 'high' risk level, measures such as installing guarding, implementing safety interlocks, or modifying work procedures might be necessary to reduce the probability or severity and bring the risk level down to 'medium' or 'low,' which are considered acceptable. The process of evaluating the probability and severity is usually performed with a risk matrix, a chart that allows the team to easily visualize and rank the risk.