Hazard severity is the seriousness of the harm that could result if a food-safety hazard causes illness or injury. In a food-safety risk assessment, severity is considered alongside the likelihood of the hazard occurring to help determine the level of risk and the controls required.
Food-safety teams may use qualitative categories such as low, moderate, high and very high, or a numerical scale defined by the organisation. The rating should be based on the hazard, the food and the possible consequences, not simply on how often an incident has occurred. A hazard that is unlikely but could cause very serious harm may still require strong preventive controls.
Severity describes how serious the harm could be. Likelihood estimates how probable the hazard or exposure is. A risk assessment considers both, often using a risk matrix or another documented method, to prioritise control measures and monitoring.
Example: A food-safety team assesses the potential severity of botulism associated with an improperly controlled preserved food. Even if the likelihood is considered low under the current process, the possible consequences justify strict process controls and verification.
Chef’s tip: Do not rate severity only by the number of previous incidents. Consider the credible worst-case outcome and the people who may be exposed.
Key distinction: Hazard severity is the potential seriousness of harm. Hazard likelihood is the probability that the hazard will occur or cause exposure; both contribute to the overall risk assessment.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
