Ecotoxicology: behavior of chemical substances

The use and impact of chemicals on man and the environment are governed at European level by various regulations. One of the most important aspects to consider is the distinction between hazard and risk. Hazard is an intrinsic property of a substance that depends on its structure, whereas risk is a function of exposure to the substance throughout its life cycle (production, use and disposal, etc.). For risk to be proven, there must be an emission source, a vector (environmental or other) and a target. If one of these three parameters is missing, the substance presents no risk. This notion is often difficult to grasp, and every day in the press and the media we find amalgams that lead to conclusions, alerts or even bans based solely on danger criteria, to which the precautionary principle is applied.

The purpose of this dossier is to briefly present the methodology used to carry out the risk assessment of a substance within the framework of European regulations, and in particular to describe the various criteria used to study the behavior of this substance in the environment. The study of the substance's fate in the various environmental compartments and the determination of its effects on environmental flora and fauna will be presented in the dossier [SE 1 602] .