Pesticides and aquatic organisms – EFSA publishes new guidance

The PPR Panel was asked to update the guidance in order to address the latest regulatory and scientific developments that have taken place since the document was originally produced by the European Commission in 2002[1].  It was carried out as part of EFSA’s ongoing work to help protect consumers, animals and the environment from risks related to pesticides.

The guidance for assessing risks from pesticides was developed following an extensive public consultation in which hundreds of comments submitted by key stakeholders were taken into account. It provides advice on how to analyse whether the concentrations of pesticides present in these so-called edge-of-field surface waters pose a short- or long-term threat to aquatic organisms. The document provides detailed guidance on how to assess the effects of pesticides on aquatic organisms and how to link these to an exposure assessment.

The primary aim of the guidance is to safeguard overall population levels of aquatic organisms. In consultation with risk managers, the PPR Panel has also set out measures to provide enhanced protection for aquatic vertebrates such as fish and amphibians. 

To achieve these aims, the guidance details two schemes which can be used by risk managers to assess the possible effect of pesticides on aquatic organisms based on the desired protection goals. These are:

• The ecological threshold A dose or exposure below which adverse effects are not detected. option (ETO) - which only allows for negligible effects on aquatic organisms.
• The ecological recovery The return of a population or ecosystem to a pre-defined status after a disturbance to its normal activities (e.g. exposure to a toxin or pest, or a change in food supply).  option (ERO) – which allows for some adverse effects on populations of aquatic organisms as long as these recover within an acceptable time period.

As in the previous guidance, the revised document proposes a tiered assessment method to achieve these protection goals.  However, the latest guidance gives more detailed advice on how to apply the tiered assessment approach to provide a harmonised framework for all risk assessors in the EU.

The new tiered assessment method progresses from a basic initial stage using legally required core data to more complex and sophisticated higher tiers.  The first tier uses a conservative approach that incorporates a high safety factor into assessments. This means risks to aquatic organisms from pesticides are assessed at concentration levels that are unlikely to occur when the substances are used according to good agricultural practice. The assumption being that if no risk is indicated at the lower tier, then a threat to aquatic organisms from the substances can effectively be ruled out. Where a risk cannot be initially excluded, higher tier assessments of the effects of pesticides on aquatic organisms provide a more refined risk evaluation.

The guidance document also gives detailed advice on how to derive legally permissible levels of pesticides in water – known as Regulatory Acceptable Concentrations (RAC) - that protect aquatic organisms in line with the two proposed assessment schemes.

EFSA will be holding an information session on the guidance document for all stakeholders in November 2013.

• Guidance on tiered risk assessment for plant protection products for aquatic organisms in edge-of-field surface waters

Related feature story: Q

Event: EFSA Info Session with stakeholders on revised aquatic ecotoxicology guidance