Words matter in toxicology and risk assessment as they impact risk communication

Clear, consistent language is essential in toxicology and risk assessment because terminology directly affects risk communication and understanding. The original concept of a "No Harm Dose of Reasonable Certainty" (NHDoRC) for an amount of chemical to which people can be exposed without detrimental effects is a plain language expression that clearly describes regulatory intent. However, the subsequent introduction and use of many related technical terms, such as NOAEL, BMD, RP, and PoD, with almost the same meaning, can confuse non-experts and even scientists working in different regulatory entities. Similarly, ADI, RfD, TDI, MRL, HBGV, and RV are all different abbreviations used in toxicology and risk assessment to describe the "acceptable" human dose in the context of food, water, and environmental chemicals. Likewise, the frequent use of terms such as margin of exposure (MoE) and margin of safety (MoS) interchangeably further complicates communication, as they are mathematically (and toxicologically) quite different. NOAEL and BMD10 are sometimes used interchangeably, but they usually represent two different points on the dose-response curve. Because of the many complications in the terminology used in risk assessment, a committee should be established to harmonize terminology across agencies and the wider risk assessment community, including industry and academia. The recommendations from such a committee would improve clarity, transparency, regulatory efficiency, and public trust in chemical risk assessment.