Update Evalutation Manual plant protection products for birds & mammals and aquatox

News item | 23-03-2017 | 09:00

Update birds & mammals

Due to new public literature a small change and addition has been made in the section on mammals. The change concerns a generic PD (Fraction of food type in diet ) refinement for small herbivorous mammals. In the risk assessment a worst-case assumption is made, using the most susceptible animal, based on body weight and diet composition. The most worst case scenario concerns small herbivorous mammals ( like voles), assuming a diet of grasses only. In the current evaluation manual both an acute and chronic PD refinement has been included for crops without a grassy vegetation (agricultural crops, flower bulbs etc). The acute PD as per E.M. 2.1 will remain unchanged. For the chronic risk assessment, the PD will be set on 50% grass and 50% non-grass herbs in crops with no/low levels of grass vegetation. A chronic PD of 75% grasses and 25% non-grass herbs can be used in crops with large areas of grass vegetation (grasslands, orchard etc).

Aquatox: Algae / aquatic plants endpoint used in the risk assessment

The Board has decided to follow in principle the EFSA aquatic guidance document (EFSA, 2013) with respect to the use of the growth rate (E_rC₅₀) endpoint in the risk assessment for algae and aquatic plants. The date of entry into force of this decision is the 1st of January 2017.

EFSA is currently working on the corrigendum of the EFSA aquatic guidance document (2013) and one of the exercises is a calibration to evaluate whether the protection goal is achieved growth rate is used. The previous guidance document (SANCO) used the lowest endpoint of a study and in most cases this concerns E_yieldC₅₀/E_biomassC₅₀ (both being significantly lower than the E_rC₅₀). 

Until further notice the following procedure will be applied for risk assessments on algae and aquatic plants:

1. Ctgb will perform the risk assessment according to the approved guidance and will therefore use endpoints based on growth rate, as of January 1st 2017;
2. For new applications the Ctgb will notify applicants that guidance might change in the near future, in which endpoints based on yield might be used instead of growth rate. Thus, Ctgb will ask the applicant whether a risk assessment based on yield endpoints is wanted by the applicant. If desired by the applicant, endpoints based on yield will be used in the risk assessment, if not, endpoints based on growth rate will be used, as per the current guidance;
3. For ongoing applications in which the risk assessment, based on yield, is assessed as acceptable with the use of mitigation measures (e.g. drift reducing measures) the Ctgb will ask the applicant if  yield endpoints should stay, or if they would prefer that the growth rate endpoint be used in the risk assessment instead;
4. Already approved products that are assessed based on yield endpoints will not be reassessed based on growth endpoints;
5. Applicants are free, following on the procedure in other member states and in anticipation of possible changes in the guidance, to submit a risk assessment based on yield endpoints.

It is acknowledged that uncertainty is introduced with respect to the protectiveness of the risk assessment for algae and aquatic plants when a growth rate endpoint is used in the risk assessment (as the E_rC₅₀ for algae is in general a factor of 4-5 higher than the E_yC₅₀ and for aquatic plants this is about a factor of 2, while the trigger values have not changed). To reduce the uncertainty introduced by the use of the growth rate endpoint, the following approach will be followed:

• If the PEC/RAC¹ ratio based on the E_rC₅₀ for algae and/or aquatic plants is just below the trigger of ≤1 (factor of 2 or less below the trigger: 0.5 > PEC/RAC ≤1), and the PEC/RAC based on E_yC₅₀ is clearly higher than trigger of ≤1 (factor of 2 more: PEC/RAC ≥2), the protectiveness of the risk assessment comes into question. In such cases drift reduction measures one class higher than would be necessary on basis of the risk assessment with the E_rC₅₀ should be applied (e.g. from DRT class 50% to DRT class 75%, or from DRT class 75% to DRT class 90%). If it is not possible to go to a higher drift reduction class, because based on the E_rC₅₀ the highest possible drift reduction class should be applied, the possible risk in the assessment will be highlighted and clearly described, and the decision will be left to the Board how to proceed with the application.
• ¹ PEC is the concentration in the surface water and the RAC is the endpoint divided by the assessment factor.

Please consult the Service Desk (servicedesk@ctgb.nl) for any questions regarding this update.