CONCLUSION ON PESTICIDE PEER REVIEW Conclusion regarding the peer review of the pesticide risk assessment of the active substance bensulfuron Issued on 26 September 2008

Bensulfuron is one of the 84 substances of the third stage Part B of the review programme covered by Commission Regulation (EC) No 1490/2002(1). This Regulation requires the European Food Safety Authority (EFSA) to organise upon request of the EU-Commission a peer review of the initial evaluation, i.e. the draft assessment report (DAR), provided by the designated rapporteur Member State and to provide within 6 months a conclusion on the risk assessment to the EU-Commission. Italy being the designated rapporteur Member State submitted the DAR on bensulfuron in accordance with the provisions of Article 10(1) of the Regulation (EC) No 1490/2002, which was received by the EFSA on 11 September 2006. The peer review was initiated on 24 November 2006 by dispatching the DAR for consultation of the Member States and the sole applicant United Phosphorus Limited. Subsequently, the comments received on the DAR were examined and responded by the rapporteur Member State in the reporting table. This table was evaluated by EFSA to identify the remaining issues. The identified issues as well as further information made available by the applicant upon request were evaluated in a series of scientific meetings with Member State experts in May-June 2008 A final discussion of the outcome of the consultation of experts took place during a written procedure with the Member States in September 2008 leading to the conclusions as laid down in this report. The conclusion was reached on the basis of the evaluation of the representative uses as a herbicide on rice for the control of broad-leaved weeds and Cyperaceae as proposed by the notifier. Full details of the GAP can be found in the attached list of endpoints. The representative formulated product for the evaluation was Londax (R), a water-dispersible granule (WG) containing 600 g/kg of bensulfuron-methyl which is a variant of bensulfuron(2). The technical specification is not finalised, a data gap was identified for a revised specification. Sufficient analytical methods as well as methods and data relating to physical, chemical and technical properties are available to ensure that quality control measurements of the plant protection product are possible. Adequate methods are available to monitor bensulfuron-methyl residues in food/feed of plant origin, soil, surface water and air; however no monitoring methods were submitted for the metabolites set as part of the residue definition in ground water. An analytical method for food of animal origin is not required due to the fact that no residue definition is proposed. In the mammalian metabolism studies, bensulfuron-methyl was rapidly but incompletely absorbed after oral administration. It was distributed mainly to the gastrointestinal tract, liver, kidneys and plasma and was extensively metabolised, showing no potential for accumulation. The acute toxicity was low, either by the oral, dermal or inhalation route; no eye or skin irritation was observed and no skin sensitisation potential was found in a Magnusson & Kligman test. The main target organ of bensulfuron-methyl was the liver upon short term or long term exposure in either the rat, mouse or dog species; the relevant NOAEL for both short term and long term exposure was the dose level of 19.9 mg/kg bw/day from the one-year dog study. No potential for neurotoxicity, genotoxicity or carcinogenicity was seen with bensulfuron-methyl; no reproductive or fertility effects were observed in a two-generation reproduction toxicity study. Some unspecific effects or delay in the development of rats were observed upon high dosing of bensulfuron-methyl without expressing maternal toxicity, in rabbits only decreased body weight was observed at maternal toxic doses. The Acceptable Daily Intake (ADI) of bensulfuron-methyl was 0.2 mg/kg bw/day based on the 1-year dog study, applying a safety factor of 100; the Acceptable Operator Exposure Level (AOEL) was 0.12 mg/kg bw/day based on the same 1-year dog study, safety factor of 100, and applying a correction factor of 60 % for low oral absorption; no Acute Reference Dose (ARfD) was allocated. Dermal absorption was 5.9 % for the concentrate representative formulation and 7.2 % for the in-use spray dilution, based on an in vivo study in rat. The level of operator exposure calculated for the representative formulation Londax (R) (a water dispersible granule (WG) formulation containing 600 g/kg of bensulfuron-methyl), at a maximum dose rate of 0.06 kg bensulfuron-methyl/ha in rice was below the AOEL according to the UK POEM, only when the use of personal protective equipment (PPE) as gloves during mixing/loading and application was considered; according to the German model, estimated exposure was below the AOEL even when no PPE were worn. Estimated exposure of workers entering crops treated with bensulfuron-methyl was below the AOEL, without the use of PPE. Bystander exposure was low compared to the AOEL value. In metabolism studies with radio labelled bensulfuron-methyl in paddy rice, upon application to the water surface, levels of total radioactivity recovered in rice plants were very low and hence identification of residues was limited to the extractable radioactivity from foliage and straw. Neither intact bensulfuron-methyl nor bensulfuron was detected, but, though at very low levels, some metabolites could be identified that indicate a cleavage of the sulfonylurea bridge occurred. In the meeting of experts the need for further data on the nature of the residue in plants with foliar exposure and in rotational crops was identified. Therefore a residue definition for risk assessment and MRL setting purposes could only be proposed provisionally as bensulfuron-methyl. Residue trials with post-emergence application to rice plants indicate that under practical conditions, residues of bensulfuron-methyl above the limit of quantification (LOQ) are not expected in rice grain, while in rice straw residues above the LOQ could be found in one trial. In a confined rotational crop study total residues in the rotated crops did not exceed 0.01 mg/kg, however data indicated an increase of residues in rotated cereals with time and thus clarification on potential uptake of soil metabolites is required. No significant residues are expected to occur in commodities to be processed or used in livestock diet, and therefore no further investigation in processing studies and livestock studies is required to support the representative uses in rice. In a provisional chronic consumer exposure and risk assessment, based on the provisional residue definition for risk assessment, it was demonstrated that the maximum estimated dietary intake of residues of bensulfuron-methyl is well below (<1%) the toxicological reference value ADI. As no ARfD was allocated an acute risk assessment is not considered necessary. Based on the available environmental fate and behaviour studies in aerobic soil and aerobic natural sediment water systems it was identified that bensulfuron-methyl and the breakdown products IN-F78803 (max 9.7% applied radioactivity (AR) in whole natural sediment water systems), bensulfuron (max 27.7% AR in soil), IN-J02904(max 46% AR in soil), IN-N52975 (max 31.7% AR in whole natural sediment water systems), IN-DAT976 (max 9.9% AR in whole natural sediment water systems) and IN-D1R847 (max 18.2% AR in soil) needed environmental exposure assessments. In a sterilised natural water (indirect) aqueous photolysis study IN-T58318 was formed at up to 13.7% AR. An environmental exposure assessment was also completed for this metabolite. These observed formation fractions were used as the basis for calculating the available environmental exposure assessments. Bensulfuron-methyl was characterised as exhibiting moderate to high persistence, IN-F7880 low to medium persistence, bensulfuron low to moderate persistence, IN-J0290 low to moderate persistence, IN-N5297 low to medium persistence, IN-T5831 no data available but considered to have moderate persistence on the basis of structural similarity to IN-J0290, IN-DAT97 moderate persistence and IN-D1R84 low to moderate persistence. Mineralisation of both the phenyl and pyrimidine rings to carbon dioxide accounted for 12-39% AR after 95-119 days and 2-25% AR after 95-119 days respectively in the available aerobic studies. The formation of unextractable residues was a significant sink, accounting for 11-37 % AR (same radiolabels, results amalgamated) after 95-119 days in these studies. A data gap was identified for experimental data on the route and rate of degradation of bensulfuron-methyl under aerobic flooded soil conditions (that needs to include alkali soil conditions). Bensulfuron-methyl was characterised as exhibiting medium to low mobility, IN-F7880 high to medium mobility, bensulfuron very high to low mobility, IN-J0290 high to low mobility, IN-N5297 very high to high mobility, and IN-D1R84 very high mobility. For IN-T5831 and IN-DAT97 no experimental data were available and a data gap was identified. The environmental exposure assessment was completed assuming that these two compounds (IN-T5831 and IN-DAT97) exhibited very high mobility. Using this assumption the assessment indicated that mitigation to reduce the potential for the exposure of groundwater may be necessary for these two metabolites for one of the applied for intended uses in situations represented by the MED-Rice sand groundwater scenario. The information available was insufficient to enable a satisfactory environmental exposure assessment to be completed in line with agreed MED-Rice (2003) guidance(9), due to the data gaps identified above. A triggered higher tier exposure assessment for bensulfuron-methyl regarding natural surface water and sediment for situations represented by the MED-Rice sand soil scenario and for all scenarios where application is made before sowing the rice crop is missing. Whilst a higher tier exposure assessment regarding natural surface water and sediment for situations represented by the MED-Rice clay soil scenario for bensulfuron-methyl and post planting applications is available, the Member State experts did not accept the soil DT50 used as input (field dissipation value) to the RICEWQ module of the simulations or the way the exposure concentrations (90th percentile 14 day TWA values) provided by the applicant had been calculated. The experts agreed that there was a data gap for 90th percentile 14 day TWA values to be represented in a way that has some meaning for an edge of field risk assessment. The approach used by the applicant in the available assessment mixed temporal and spatial factors in an inappropriate way, such that the resulting aquatic risk assessment does not demonstrate in which (if any) situations the active substance might be used without impacting on populations of aquatic species, which is what Member State experts agreed would be required to demonstrate compliance with annex VI criteria. It can be concluded that the potential for bensulfuron-methyl to contaminate vulnerable groundwater above the parametric drinking water limit of 0.1 mu g/L from the applied for intended uses is low. For the known metabolites, based on the available data, there are indications that this is also the case when applications are made to paddies with a 10cm layer of water overlying the soil and for shallower paddy water depths in situations represented by the MED-Rice clay scenario. However in situations represented by the MED-Rice sand scenario where applications are made to paddies with <10cm overlying water it cannot be excluded with the available data that IN-5297, IN-T5831 and IN-DAT97 may be present in vulnerable groundwater at > 0. 1 mu g/L (calculations indicate concentrations up to 0.23 mu g/L). Therefore a non relevance assessment for these three metabolites was triggered, but these are not available. In the absence of data to assess the non relevance of these metabolites, the available groundwater exposure assessments indicate that risk management options may be effective at mitigating the potential for groundwater exposure by these metabolites in regions represented by the MED-Rice sand scenario. However the groundwater assessment for metabolites cannot be finalised until the data gap for experimental data on the route and rate of degradation of bensulfuron-methyl under aerobic flooded soil conditions (that needs to include alkali soil conditions) has been filled. Bensulfuron-methyl is used as a herbicide and it is very toxic to aquatic and terrestrial plants. A low risk to the aquatic environment (algae and macrophytes) was not demonstrated using the submitted data and further refinement of the aquatic risk assessment is needed. The risk to non-target terrestrial plants in the off-field area needs to be mitigated. Risk mitigation comparable to an in-field no-spray buffer zone of 5 m is required to protect non-target terrestrial plants. The risk to birds, mammals, fish and aquatic invertebrates, bees, non-target arthropods, earthworms, soil non-target macro- and micro-organisms, and biological methods of sewage treatment was assessed as low for the representative uses evaluated.