TY - JOUR

T1 - Scientific Opinion about the Guidance of the Chemical Regulation Directorate (UK) on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessments

AU - EFSA Panel on Plant Protection Products and their Residues (PPR)

AU - Ockleford, Colin

AU - Hernandez-Jerez, Antonio F.

AU - Hougaard Bennekou, Susanne

AU - Klein, Michael

AU - Adriaanse, Thomas Paulien

AU - Berny, Philippe

AU - Brock, Theodorus

AU - Duquesne, Sabine

AU - Grilli, Sandro

AU - Kuhl, Thomas

AU - Laskowski, Ryszard

AU - Machera, Kyriaki

AU - Pelkonen, Olavi

AU - Pieper, Silvia

AU - Stemmer, Michael

AU - Sundh, Ingvar

AU - Teodorovic, Ivana

AU - Topping, Chris J.

AU - Wolterink, Gerrit

AU - Smith, Robert H.

AU - Gimsing, Anne Louise

AU - Kasteel, Roy

AU - Boivin, Arnaud

AU - van der Linden, Ton

AU - Oriol Magrans, Jose

AU - Egsmose, Mark

AU - Tiktak, Aaldrik

PY - 2018/8/27

Y1 - 2018/8/27

N2 - The EFSA Panel on Plant Protection Products and their Residues reviewed the guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessment. The inclusion of aged sorption is a higher tier in the groundwater leaching assessment. The Panel based its review on a test with three substances taken from a data set provided by the European Crop Protection Association. Particular points of attention were the quality of the data provided, the proposed fitting procedure of aged sorption experiments and the proposed method for combining results obtained from aged sorption studies and lower-tier studies on degradation and adsorption. Aged sorption was a relevant process in all cases studied. The test revealed that the guidance could generally be well applied and resulted in robust and plausible results. The Panel considers the guidance suitable for use in the groundwater leaching assessment after the recommendations in this Scientific Opinion have been implemented, with the exception of the use of field data to derive aged sorption parameters. The Panel noted that the draft guidance could only be used by experienced users because there is no software tool that fully supports the work flow in the guidance document. It is therefore recommended that a user-friendly software tool be developed. Aged sorption lowered the predicted concentration in groundwater. However, because aged sorption experiments may be conducted in different soils than lower-tier degradation and adsorption experiments, it cannot be guaranteed that the higher tier predicts lower concentrations than the lower tier, while lower tiers should be more conservative than higher tiers. To mitigate this problem, the Panel recommends using all available higher- and lower-tier data in the leaching assessment. The Panel further recommends that aged sorption parameters for metabolites be derived only from metabolite-dosed studies. The formation fraction can be derived from parent-dosed degradation studies, provided that the parent and metabolite are fitted with the best-fit model, which is the double first-order in parallel model in the case of aged sorption.

AB - The EFSA Panel on Plant Protection Products and their Residues reviewed the guidance on how aged sorption studies for pesticides should be conducted, analysed and used in regulatory assessment. The inclusion of aged sorption is a higher tier in the groundwater leaching assessment. The Panel based its review on a test with three substances taken from a data set provided by the European Crop Protection Association. Particular points of attention were the quality of the data provided, the proposed fitting procedure of aged sorption experiments and the proposed method for combining results obtained from aged sorption studies and lower-tier studies on degradation and adsorption. Aged sorption was a relevant process in all cases studied. The test revealed that the guidance could generally be well applied and resulted in robust and plausible results. The Panel considers the guidance suitable for use in the groundwater leaching assessment after the recommendations in this Scientific Opinion have been implemented, with the exception of the use of field data to derive aged sorption parameters. The Panel noted that the draft guidance could only be used by experienced users because there is no software tool that fully supports the work flow in the guidance document. It is therefore recommended that a user-friendly software tool be developed. Aged sorption lowered the predicted concentration in groundwater. However, because aged sorption experiments may be conducted in different soils than lower-tier degradation and adsorption experiments, it cannot be guaranteed that the higher tier predicts lower concentrations than the lower tier, while lower tiers should be more conservative than higher tiers. To mitigate this problem, the Panel recommends using all available higher- and lower-tier data in the leaching assessment. The Panel further recommends that aged sorption parameters for metabolites be derived only from metabolite-dosed studies. The formation fraction can be derived from parent-dosed degradation studies, provided that the parent and metabolite are fitted with the best-fit model, which is the double first-order in parallel model in the case of aged sorption.

KW - aged sorption

KW - guidance

KW - leaching

KW - modelling

KW - plant protection products

KW - review

U2 - 10.2903/j.efsa.2018.5382

DO - 10.2903/j.efsa.2018.5382

M3 - Journal article

AN - SCOPUS:85062038850

VL - 16

JO - EFSA Journal

JF - EFSA Journal

SN - 1831-4732

IS - 8

M1 - e05382

ER -