Guidance changes for bird and mammal risk assessment for plant protection products

Key differences

Section	Subject	Extent of changes compared to 2009 EFSA guidance	Key changes highlighted by HSE
1	Background and terms of reference	Minor	None
2	Introduction	Minor	None
3	Risk assessment background	Minor	None
4	Problem formulation	New addition	Inclusion of an explicit problem formulation step.
5.2.6.1	Effect assessment	Minor	Additional recommendations included regarding the use of historic control data.
5.2.6.3 & Appendix D	Effect assessment	New addition	New extrapolation factors included to estimate LD50 values, where there is less than 50% mortality in acute toxicity studies with mammals.
5.2.6.5 & Appendix C	Effect assessment	Minor	Includes detailed information on which mammalian endpoints are ecotoxicologically relevant for the reproductive risk assessment (i.e. which mammalian endpoints impact population abundance).
5.2.7	Effect assessment	Extensive	Use of 10% effect level to determine biological relevance and use of benchmark dose modelling to determine the EL10 (10% effect level dose).
5.2.9	Effect assessment	New addition	Added consideration of risks to migratory birds from neurotoxic effects of pesticide active substances.
5.3.3	Effect assessment	Moderate	Modification to the approach for using a geometric mean LD50 where multiple acute toxicity studies are available.
6.1	Exposure assessment	New addition	Discussion on the use of toxicokinetic/toxicodynamic (TKTD) models in bird and mammal risk assessment.
6.1.4	Exposure assessment	Extensive	Revised approach for determining whether toxic effects could be due to short-term exposure, and hence whether a time-weighted average factor (fTWA) < 1 can be used in reproductive risk assessments for birds and mammals.
6.2.1 & Appendix I	Exposure assessment	New addition	For PPPs applied as sprays, consideration of risks to birds and mammals in off-crop environments.
6.2.2 & Appendix E	Exposure assessment	Moderate	There are differences in crop groupings and shortcut values for exposure calculations are no longer included.
6.2.3 & Appendix F	Exposure assessment	Moderate	Updated data on body weight and proportion of food items in the diets of model species are included.
6.2.4 & Appendix J	Exposure assessment	Moderate	Updated data on initial residue values in food items are included for use in exposure calculations. The geometric mean is used, rather than the median, to characterise the central tendency of these datasets.
6.2.6 & Appendix L	Exposure assessment	Moderate	The use of deposition values in the exposure assessment is revised. Crop interception values align with FOCUS (2014) guidance.
6.3 & Appendix M	Exposure assessment	Minor	Addition of a default fTWA value for seedlings.
6.5.2-6.5.5	Exposure assessment	Extensive	Inclusion of new recommendations for the conduct of field studies and their interpretation, such as the required crop coverage in the study area.
6.5.8	Exposure assessment	Extensive	Inclusion of default foraging areas to contextualise risks to birds and mammals from PPPs applied as seed treatments.
6.5.9	Exposure assessment	New addition	Inclusion of a step comparing new Tier 3 refinements with findings from previous studies, using a historic database.
7.1	Integrated exposure and effect assessment	Moderate	Inclusion of new recommendations for the conduct of field effect studies and their interpretation.
7.3	Integrated exposure and effect assessment	Moderate	Expanded consideration of the use of population models in bird and mammal risk assessment.
8 & Appendix Q	Granules	Moderate	Addition of the scenario ‘ingestion of granules when seeking seeds as food’ and removal of the scenario ‘ingestion of granules as part of soil uptake.’ Also, additional guidance for assessing risks from granules via residues in food items and from fast dissolving granules is included.
9	Metabolites	Extensive	Expanded and updated guidance for assessing risks from metabolites, following a stepwise approach.
10.2	Secondary poisoning	Moderate	Revised approach to assessing risks to birds and mammals via consumption of earthworms, using a 7-day TWA soil concentration and following the ‘pore water’ approach.
10.4	Secondary poisoning	New addition	Addition of scenarios for benthic invertebrate-eating birds and mammals.
11	Contaminated water	Minor	Additional guidance on which uses require consideration of the leaf scenario and inclusion of soil pore water approaches.
12	Formulations	New addition	For PPPs containing multiple active substances, mixture assessments are added for secondary poisoning and contaminated water exposure routes. Formulation and active substance toxicity data are compared to determine a Model Deviation Ratio (MDR).
13	Uncertainty analysis and weight of evidence	Moderate	Revised guidance for considering and presenting uncertainties associated with higher tier risk assessments.
14	Risk mitigation	Minor	None
15	Calculator tool	New addition	A new calculator tool is available for conducting risk assessments for PPPs applied as sprays or as seed treatments.

GB Proposals

HSE considers that the changes in the 2023 guidance are scientifically justified and, in general, do not raise concerns regarding practicality of implementation. However, some of the changes in the 2023 guidance could be interpreted as obliging the re-assessment of active substance toxicity data, and the defining of active substance endpoints, outside of the approval or renewal of approval process. Therefore, to ensure compliance with GB legislation, some clarification is proposed to facilitate implementation of this guidance. These proposals are discussed below.

Proposal 1

In the 2009 guidance, the toxicity endpoint used in long-term/reproductive risk assessment is a dose at which no adverse effects are seen (NOAEL), based on statistical comparison with the control group. In contrast, the 2023 guidance adopts a consistent ≥10% effect level for setting the endpoint and recommends the use of Benchmark Dose Modelling (BMD) for this purpose. While this change is scientifically merited, HSE consider it impractical to routinely determine BMD10 endpoints for use in PPP evaluations, where the active substance has been reviewed to 2009 EFSA guidance. Use of a BMD toxicity endpoint is an acceptable refinement option for risk assessments conducted to 2009 EFSA guidance.

HSE proposes to adopt use of BMD10 endpoints for all future GB active substance evaluations. However, for GB PPP evaluations, HSE proposes to either use BMD10 or NOAEL endpoints, depending on which guidance was followed when the active substance was reviewed.

Proposal 2

In both the 2009 and 2023 guidance documents, the exposure estimate used in the long-term/reproductive risk assessment incorporates a time-weighted average factor (TWA). The 2009 guidance presumes a TWA < 1 can be used as standard (unless there is evidence to the contrary), while the 2023 guidance requires this to be justified, based on a detailed review of the toxicity data. This change is scientifically merited but impractical to implement for use in PPP evaluations, where the active substance has been reviewed to 2009 guidance.

HSE proposes to apply this new approach for deciding use of a TWA factor for all future GB active substance evaluations. However, for GB PPP evaluations, HSE proposes to use the TWA approach according to the guidance in place at the most recent active substance assessment. This is with the condition that where an endpoint is set based on the LD50/10 or effects on eggshell thickness, a TWA < 1 should not be used.

Proposal 3

HSE considers that some areas of the 2023 guidance are not currently implementable, given they rely on guidance in other areas that has not yet been implemented. Specifically, this relates to the secondary poisoning and drinking water risk assessments, where exposure is considered via benthic invertebrates and/or soil pore water (Sections 10.2, 10.4 and 11).

Scientific report of EFSA on the ‘repair action’ of the FOCUS surface water scenarios

EFSA Guidance Document for predicting environmental concentrations of active substances of plant protection products and transformation products of these active substances in soil

HSE proposes that these areas of the 2023 guidance are not implemented in GB assessments until the corresponding guidance has also been implemented.

Proposal 4

Specific recommendations have been added to 2023 guidance regarding the conduct of higher-tier ecological studies and field studies investigating toxic effects in focal species (Sections 6.5.2-6.5.5 & 7.1). These recommendations include a minimum number of sites or individuals to monitor. These recommendations have been developed in the context of conducting a risk assessment that is appropriate for potentially the whole of the EU.

HSE proposes that these recommendations are considered in a GB context, reflecting the lower diversity of conditions the assessment is required to cover.

Survey

HSE proposes to adopt the 2023 EFSA guidance document for GB applications, with some clarification for how and when the guidance will apply to GB product assessments, to reflect GB legislation (see Proposals 1 to 4, above). Our survey seeks stakeholders’ views on that proposal.

The survey asks questions about potential impacts of the proposed changes to how bird and mammal risk assessments are performed for PPPs in GB.

This survey does not relate to any other aspects of the assessment of risks to non-target organisms from exposure to plant protection products.

Based on the information provided by this survey, HSE will consider whether any changes to their proposals for GB adoption of the 2023 guidance are required.

The survey closing date is xx xxxx 2026

Start survey