On May 8, 2015 the US non-profit BizNGO published a blog post on “Trending topics: hazard? Risk? Do you know the difference?”. In the short article written by Mark Rossi both terms are explained in the context of chemical risk assessment, where they have very different meanings. As such, “hazard” in chemical risk assessment describes the toxicological properties of a chemical that are most often established in toxicological tests. Thus, a chemicals hazardousness relates to its ability to cause adverse effects in humans or the environment.
On the other hand, “risk” describes the likelihood of such adverse effects to occur under given exposure conditions. This includes the dose at which chemical exposure occurs, but also the route of exposure and its timing, meaning for example exposure at a critical stage during development.
The distinction between “hazard” and “risk” is critical in chemical safety assessment. Use of some chemicals is restricted based on their hazard properties, i.e. for mutagens, chemicals that directly damage DNA and thus are assumed to play a critical first step in cancer formation. For other chemicals, like endocrine disruptors, a hazard-based approach is being discussed. This would mean that no safe levels exist for these chemicals and that they must not be used. For most other chemicals, however, thresholds are thought to exist where exposure is likely safe.
Mark Rossi (May 8, 2015). “Trending topics: hazard? Risk? Do you know the difference?”. BizNGO
Food Packaging Forum (February 26, 2014). Chemical Risk Assessment.