Step 5. Compare the hazards
The hazard or toxicity of the product evaluated in the reference assessment is reviewed to decide whether it can be considered similar to the one under review in the local situation.
Human health risk assessments are generally based on toxicological reference values such as the Acceptable Daily Intake (ADI) and Acute Reference Dose (ARfD) for dietary risks, and the Acceptable Operator Exposure Level (AOEL) for operator and worker risk assessments. If exposure exceeds the reference value, the associated risk is considered unacceptable. Generally, these reference values are globally applicable, facilitating bridging. However, in some cases it is useful to review how the toxicological reference value used in the reference assessment has been established and whether this is applicable to the local situation. This is further explained in the Toolkit for the relevant bridging methods.
For environmental risk assessment, a variety of ecotoxicological reference values is used, based on data from one or more non-target species (e.g. Regulatory Acceptable Concentration (RAC), Maximum Acceptable Concentration (MAC), Level of Concern (LOC)). These reference values may be based on different ecotoxicological endpoints (e.g. LD50, EC10, NOEC) and specific assessment or safety factors.
Since ecosystems can be very different around the world, it is important to evaluate whether the ecotoxicological data and resulting ecotoxicological reference values used in the reference assessment are applicable to the local situation. It should be stressed that the main question is not whether the ecosystems and/or non-target organisms are sufficiently similar (they often will not be). Instead, it should be assessed whether the toxicological data and safety factors used in the reference assessment are likely to provide sufficient protection to the local ecosystem or non-target organisms that may be affected by the pesticide.
Comparing environmental hazards between a reference and a local situation can be challenging. Nonetheless, it is important to note that the standard first tier ecotoxicity data, associated with the assessment/safety factor applied in many industrialized countries, tends to provide protection to a relatively large range of organisms.
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