The risk characterisation ends the chemical safety assessment (CSA) process. Carried out for each exposure scenario under the assumption that the described risk management measures are implemented, this step concerns the exposed human populations and environmental spheres. It includes also an overall environmental risk analysis.

The risk characterisation consists in:

• comparing the exposure of each exposed population with the appropriate DNEL (cf Hazard assessment);
• comparing the concentrations predicted in each environmental sphere with the PNEC (cf Hazard assessment);
• assessing the likelihood and the severity of an event arising from the physico-chemical properties of the substance.

The risk is considered as adequately controlled throughout the lifecycle of the substance if:

• the estimated exposure levels (cf Exposure assessment) are lower than the DNEL or PNEC, and
• the likelihood and the severity of an event arising from the physic-chemical properties of the substance is negligible.

In case it is not possible to determine a DNEL or a PNEC, the likelihood to avoid effects when implementing the exposure scenario shall be assessed qualitatively. Moreover, for PBT and vPvB substances, the manufacturers or importers shall use the information collected during the exposure assessment step to minimize exposures and emissions to humans and the environment.