The Environmental Risk Assessment (ERA) should be carried out in accordance with the guidelines VICH GL6 (CVMP/VICH/592/98) and VICH GL38 (CVMP/VICH/790/03). EMA has also published a supporting guideline (EMEA/CVMP/ERA/418282/2005-Rev.1) providing additional information on how to implement the VICH guidelines. The supporting guideline provides algorithms, models, and default values (standard values) for the calculation of the extent of environmental exposure of a substance. It is meant as a technical guidance document designed to facilitate the preparation of the ERA report and to harmonise the interpretation of the VICH guidelines.

Whenever applicable, an ERA report should also outline preventive and risk mitigation measures designated to minimise identified environmental risks, which will ultimately become part of the summary of product characteristics (SPC) in the form of warning statements.

Assessment of the potential environmental risks is a two-phased procedure:

• A Phase I assessment pursuant to VICH GL6 is to be carried out for all products and serves to estimate the environmental impact of a given product, its active substance(s) and excipients. Based on what is referred to as the decision tree (a set of 19 questions about the product in question), a pre-screening for ‘water’ and ‘soil’ is carried out. If the calculated concentrations in the soil (‘predicted environmental concentration,’ PECsoil < 100 µg/kg) or water (‘environmental introduction concentration,’ EICaquatic < 1 µg/L) remain below the specified trigger values, the assessment ends in Phase I.
• If the trigger values are exceeded, a Phase II assessment pursuant to VICH GL38 will be performed. Phase II assessments must be carried out for all ecto- and endoparasiticides intended for use in pasture animals and for all veterinary medicinal products used in fish farms without controlled discharge. Phase II assessments are further subdivided into Tiers A and B; based on the properties of a given substance (physicochemical, pharmacological, toxicological) and its estimated concentration in the environment, Phase II assessments deal with the degradation behaviour and the possible effects of the substance on the environment, specific water organisms, algae, and evertebrates. The risk quotient calculated in Tier A (RQ = ratio between PEC/PNEC*) determines whether the assessment can stop after Tier A (‘basic data set’) or whether further studies in Tier B are required (‘extended data set’).
  *PEC, predicted environmental concentration; PNEC, predicted no effect concentration.

For detailed information on the criteria, standards, and tests to be used and on the structure of the ERA, please refer to the Guidelines. The complete ERA must be contained in Part III of the dossier; the corresponding expert report, including the curriculum vitae and signature of its author, must be contained in Part IC.