Conclusion on the peer review of the pesticide risk assessment of the active substance chlorpyrifos 1

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1 CONCLUSION ON PESTICIDE PEER REVIEW Conclusion on the peer review of the pesticide risk assessment of the active substance chlorpyrifos 1 European Food Safety Authority 2 European Food Safety Authority (EFSA), Parma, Italy SUMMARY Chlorpyrifos is one of the substances of the first stage of the review programme covered by Commission Regulation (EEC) No 3600/92 3, as last amended by Commission Regulation (EC) No 416/ Chlorpyrifos was included in Annex I to Directive 91/414/EEC on 1 July 2006 by Commission Directive 2005/72/EC 5. It was a specific provision of the inclusion, that notifiers were required to submit to the Commission of the European Communities (hereinafter referred to as the Commission ) further studies to confirm the risk assessment for birds and mammals within two years from the entry into force of the inclusion Directive. In accordance with the specific provision, Dow AgroSciences, on behalf of the Chlorpyrifos Task Force, submitted further studies in June 2008, which were evaluated by the designated rapporteur Member State (RMS), Spain, in the form of an Addendum to the assessment report. In compliance with Guidance Document SANCO 5634/2009 rev.3, the RMS distributed the Addendum to Member States and the EFSA for comments on 30 June The RMS collated all comments in the format of a Reporting Table, which was submitted to the Standing Committee on the Food Chain and Animal Health (SCFCAH) in November Following consideration of the comments received, and the further discussions in the SCFCAH, the Commission requested the EFSA to organise a peer review of the RMS s evaluation of the confirmatory data and to deliver its conclusions on the risk assessment for birds and mammals. The conclusions laid down in this report were reached on the basis of the evaluation of the representative use of chlorpyrifos as an insecticide on grape vines, as proposed by the notifiers. Full details of the representative use can be found in Appendix A to this report. A high acute risk to birds and small herbivorous mammals such as voles cannot be excluded on the basis of the available data. A high long-term risk to mammals was identified in the refined risk assessment. Risk mitigation measures, such as no-spray buffer zones, are needed to protect fish-eating birds and mammals. 1 On request from the European Commission, Question No EFSA-Q , issued on 16 December Correspondence: praper@efsa.europa.eu 3 OJ L 366, , p OJ L 125, , p OJ L 279, , p. 63 For citation purposes: European Food Safety Authority; Conclusion on the peer review of the pesticide risk assessment of the active substance chlorpyrifos.. [14 pp.]. doi: /j.efsa Available online: European Food Safety Authority, 2011

2 peer review of the pesticide risk assessment of the active substance chlorpyrifos KEY WORDS Chlorpyrifos, peer review, risk assessment, pesticide, insecticide 2

3 TABLE OF CONTENTS Summary... 1 Table of contents... 3 Background... 4 The active substance and the formulated product... 5 Conclusions of the evaluation... 5 List of studies to be generated, still ongoing or available but not peer reviewed... 7 Particular conditions proposed to be taken into account to manage the risk(s) identified... 7 Issues that could not be finalised... 7 Critical areas of concern... 7 References... 8 Appendices

4 BACKGROUND Chlorpyrifos is one of the substances of the first stage of the review programme covered by Commission Regulation (EEC) No 3600/92 6, as last amended by Commission Regulation (EC) No 416/ Chlorpyrifos was included in Annex I to Directive 91/414/EEC on 1 July 2006 by Commission Directive 2005/72/EC 8. It was a specific provision of the inclusion that notifiers were required to submit to the Commission of the European Communities (hereinafter referred to as the Commission ) further studies to confirm the risk assessment for birds and mammals within two years from the entry into force of the inclusion Directive. In accordance with the specific provision, Dow AgroSciences, on behalf of the Chlorpyrifos Task Force, submitted further studies in June 2008, which were evaluated by the designated Rapporteur Member State (RMS) Spain in the form of an Addendum to the assessment report (Spain, 2009). In compliance with Guidance Document SANCO 5634/2009 rev.3 (European Commission, 2009), the RMS distributed the Addendum to Member States and the EFSA for comments on 30 June The RMS collated all comments in the format of a Reporting Table, which was submitted to the Standing Committee on the Food Chain and Animal Health (SCFCAH) in November Following consideration of the comments received, and the further discussions in the SCFCAH, the Commission decided to further consult the EFSA. By written request, received by the EFSA on 15 June 2010, the Commission requested the EFSA to organise a peer review of the RMS s evaluation of the confirmatory data, and to deliver its conclusions on the risk assessment for birds and mammals. The Addendum and the Reporting Table were discussed at the PRAPeR 80 Experts Meeting on ecotoxicology in August Details of the issues discussed, together with the outcome of these discussions were recorded in the meeting report. A final consultation on the conclusions arising from the peer review of the risk assessment for birds and mammals took place with Member States via a written procedure in November This conclusion report summarises the outcome of the peer review of the risk assessment for birds and mammals evaluated on the basis of the representative use as an insecticide on grape vines, as proposed by the notifiers. A list of the relevant end points for the active substance as well as the formulation is provided in Appendix A. In addition, a key supporting document to this conclusion is the Peer Review Report, which is a compilation of the documentation developed to evaluate and address all issues raised in the peer review, from the compilation of comments in the Reporting Table to the conclusion. The Peer Review Report (EFSA, 2010) comprises the following documents: the Reporting Table (revision 3; August 2010), the report of the scientific consultation with Member State experts. Given the importance of the Addendum and the Peer Review Report, both documents are considered respectively as background documents A and B to this conclusion. 6 OJ L 366, , p OJ L 125, , p OJ L 279, , p. 63 4

5 THE ACTIVE SUBSTANCE AND THE FORMULATED PRODUCT Chlorpyrifos is the ISO common name for O,O-diethyl-O-3,5,6-trichloro-2-pyridyl phosphorothioate (IUPAC). The representative formulated product for the evaluation was Dursban 480 EC, an emulsifiable concentrate (EC), containing 480 g/l chlorpyrifos. The representative use evaluated comprises application to grape vines to control post-blossom pests in Northern and Southern Europe. CONCLUSIONS OF THE EVALUATION The risk assessment was based on the following documents: European Commission (2002a), EFSA (2009). The refined risk assessment for birds and mammals was discussed in the PRAPeR 80 ecotoxicology experts meeting in August To refine the acute risk assessment for birds an LD 50 from a 1 hour dietary study on Bobwhite quail (Colinus virginianus) was proposed. The majority of the experts were of the opinion that this dietary study could be considered as valid but uncertainties remained with regard to the actual uptake of treated food by birds. It was noted that avoidance was observed in the study. Therefore, the experts concluded that the endpoint from such a study cannot be used to replace the standard acute LD50 in TER calculations due to uncertainties in the exposure actually encountered in the study and also likely to occur in the field due to differences in feeding rates. However the study may be used in a weight of evidence approach if the TER would be close to the trigger. As an alternative approach, a geometric mean or an HC5 (hazardous concentration 5%) of acute endpoints from 20 different bird species was proposed by the RMS. However, the experts noted that many of the acute studies used to derive a geometric mean or an HC5 were not performed according to the standard test guidelines, with endpoints sourced from open literature. Therefore, due to the uncertainties within the database of acute studies it was suggested that the data could only be used in a qualitative way as additional information. It was agreed that residue data in insects should include residues in dead insects, since residues in dead insects were 3-6 times higher than in live insects. It was suggested that the measured residues in ground-dwelling arthropods should be adjusted using a mean factor of 3.4 (based on 6 trials) to account for only live insects being caught in pitfall traps. It was noted that using the mean value would not be a conservative approach, and that this should be taken into account in the decision whether it is appropriate to follow a weight of evidence approach. The refined acute risk assessment (including focal species, PD refinement and measured residues) resulted in a TER of 4.2, which is significantly below the Annex VI trigger of 10. The short-term risk to insectivorous birds was assessed as low based on refined insect residue data. The focal species Black Redstart (Phoenicuros ochruros) and the suggested PD refinement were accepted for refinement of the long-term risk. The refined risk assessment for Cirl Bunting (Emberiza cirlus) was not sufficiently supported by data and hence was not further considered in the refined risk assessment. The refined long-term risk assessment resulted in TERs above the Annex VI trigger of 5 for Black Redstart. A field study was submitted. The study was conducted in vineyards in southern Europe at an application rate of 2 x 360 g a.s./ha. Of the radio-tracked birds, only one bird was found dead but there was no evidence that the death was related to the application of chlorpyrifos. It was noted that the study was conducted at a higher application rate than the representative use rate. However several 5

6 uncertainties were identified by the experts: the study covered short-term effects on adults but not nestlings; the study might not cover Northern Europe due to slower degradation rates in cooler climates, different bird species and different agricultural practices; the study was conducted in June while the proposed GAP is for late applications (21 days pre-harvest). It was finally concluded that the study is useful as additional information but is not sufficient to give a clear indication of low risk to birds. Overall it is concluded that the short-term and long-term risk to birds is low. Since uncertainties remain with regard to the acute risk to birds, a high acute risk to birds cannot be excluded on the basis of the available data. The risk to earthworm-eating birds and mammals from secondary poisoning was assessed as low. The risk to fish-eating birds and mammals was assessed as high at tier 1. Risk mitigation such as no-spray buffer zones are needed to minimize entry into surface water. The available risk assessment suggests that a concentration in surface water equivalent to 10 times the EAC (environmentally acceptable concentration, which should not be exceeded in the aquatic environment) would result in TERs above the trigger of 5 for fish-eating birds and mammals. The acute risk to mammals was assessed as low for rabbit (Oryctolagus cuniculus), wood mouse (Apodemus sylvaticus) and common shrew (Sorex araneus) including refinement of residues in food items. However, a high acute risk was still indicated in the refined risk assessment for small herbivorous mammals such as common vole (Microtus arvalis). A field study conducted in orchards in Germany was submitted and discussed in the meeting of experts. A higher application rate (1 x 500 g a.s./ha) was applied in the study but several shortcomings were noted: only small numbers of voles were caught in individual plots and a high variability was observed; the timing of the study (application in October) did not match the proposed GAP; the application was made during a period where vole populations were also declining in control plots; the population decline in the treated plots was higher than in control plots. The population decline in the controls (due to autumn season) means that there is a low probability of detecting adverse effects in this study. Overall it was concluded that there was a trend for an effect in the treated plots, and that the study does not provide evidence that the acute risk to small herbivorous mammals is low. The long-term endpoint to be used in the risk assessment for mammals was discussed in the meeting of experts. It was agreed that the NOAEL from the 2-generation rat study of 1 mg a.s./kg bw/d based on reduced pup survival should be used in the long-term risk assessment. This is in line with the toxicology evaluation of the available data. The refined long-term TERs, including residue decline, exceeded the trigger of 5 only for common shrew, however the TERs for vole, rabbit and wood mouse were still significantly below the Annex VI trigger of 5, indicating a high long-term risk to mammals. 6

7 LIST OF STUDIES TO BE GENERATED, STILL ONGOING OR AVAILABLE BUT NOT PEER REVIEWED The acute risk to birds needs to be addressed further (relevant for the representative use evaluated; submission date proposed by the notifier: none; see section 5). The acute risk to small herbivorous mammals needs to be addressed further (relevant for the representative use evaluated; submission date proposed by the notifier: none; see section 5). The long-term risk to mammals needs to be addressed further (relevant for the representative use evaluated; submission date proposed by the notifier: none; see section 5). PARTICULAR CONDITIONS PROPOSED TO BE TAKEN INTO ACCOUNT TO MANAGE THE RISK(S) IDENTIFIED Risk mitigation measures, such as no-spray buffer zones, are required to protect fish-eating birds and mammals. The concentration in surface water must not exceed 1 µg a.s./l. (see section 5). ISSUES THAT COULD NOT BE FINALISED None. CRITICAL AREAS OF CONCERN A high acute risk to birds cannot be excluded. A high acute risk to small herbivorous mammals cannot be excluded. A high long-term risk to mammals was indicated. 7

8 REFERENCES EFSA (European Food Safety Authority), Peer Review Report to the conclusion regarding the peer review of the pesticide risk assessment of the active substance chlorpyrifos. Spain, Addendum to the assessment report on the active substance chlorpyrifos prepared by the rapporteur Member State Spain in the framework of Directive 91/414/EEC, updated September 2010 (rev. 4). Guidance documents 9 : EFSA (European Food Safety Authority), Guidance Document on Risk Assessment for Birds and Mammals on request of EFSA. EFSA Journal 2009; 7(12):1438 European Commission, 2002a. Guidance Document on Risk Assessment for Birds and Mammals Under Council Directive 91/414/EEC. SANCO/4145/2000. European Commission, Guidance document on the procedures for submission and assessment of confirmatory data following inclusion of an active substance in Annex I of Council Directive 91/414/EEC. SANCO/5634/2009 rev.3. FOCUS (2007). Landscape And Mitigation Factors In Aquatic Risk Assessment. Volume 1. Extended Summary and Recommendations. Report of the FOCUS Working Group on Landscape and Mitigation Factors in Ecological Risk Assessment, EC Document Reference SANCO/10422/2005 v pp. 9 For further guidance documents see (EC) or (OECD) 8

9 APPENDICES APPENDIX A LIST OF END POINTS FOR THE ACTIVE SUBSTANCE AND THE REPRESENTATIVE FORMULATION Summary of representative uses evaluated (Emboldened values are GAP, other applications details are consequential to the spray volumes) Crop and/or situation (a) Member State or Country Grape vines N. & S. Europe Product Name Dursban 480 EC F G or I (b) Pests or Group of pests controlled (c) (d-f) (i) F Post-blossom pests EC 480 g/l Formulation Application Application rate per treatment PHI (days) Type Conc. Method Number kg kg a.s./ha of a.s. Kind a.s./hl (f-h) Abmb, HL Growth stage & season (j) min max (k) Interval between apps. (min) min max water (L/ha) min max min max (l) Remarks Fruiting# 1 N/A # Timing of application to be consistent with minimal exposure to bees. [1] [2] [1] A high long-term risk is identified for mammals. [2] A high acute risk to birds and small herbivorous mammals cannot be excluded Remarks (a) For crops the EU and Codex classifications (both) should be used. (h) Kind, e.g. overall, broadcast, aerial spraying, row, individual plant, between the plants (b) Outdoor or field use (F), glasshouse application (G) or indoor (i) g/kg or g/l application (I) (c) e.g. biting and sucking insects, soil borne insects, foliar fungi, weeds (j) Growth stage at last treatment, including where relevant information on season at time of application (d) e.g. wettable powder (WP),emulsifiable concentrate (EC), granule (GR) (k) The minimum and maximum number of applications possible under practical conditions must be given (e) GIFAP Codes - GIFAP Technical Monograph No. 2, 1989 (l) PHI - Pre-harvest interval (f) All abbreviations must be explained (m) Remarks may include: Extent of use/ economic importance/restrictions (e.g. (g) Method, e.g. high volume spraying, low volume spraying, spreading, dusting, drench feeding/grazing)/minimal intervals between applications Abmb Air blast mist blower; Fbs Field boom sprayer; HL Hand lance. (m) 9

10 Section 3: Ecotoxicology Effects on terrestrial vertebrates (Annex IIA, point 8.1, Annex IIIA, points 10.1 and 10.3) Acute toxicity to mammals Mouse (females) LD50= 64 mg/kg b.w. Long-term toxicity to mammals Rat 2 generations NOAEL = 1 mg/kg bw/day Acute toxicity to birds Active substance: Passer domesticus LD50 = 122 mg as/kg Coturnix coturnix LD50 = 13.3 mg/kg bw 95th percentile of the Species Sensitivity Distribution, 6.9 mg as/kg bw Geometric mean: 25.4 mg/kg bw (to be used only in a qualitative way - PRAPeR 80) Formulation: Phasianus colchicus LD50 =8.41 mg/kg bw Acute dietary toxicity to birds Dietary toxicity to birds Reproductive toxicity to birds Field effects study Bobwhite quail: 1h-LD50 = 75 mg as/kg bw (To be used only in a weight of evidence approach - PRAPeR 80) Mallard duck LC50= 203 ppm (= 71 mg as/kg bw/d) (a value of 180 was obtained in another study not fully validated) Mallard duck NOEC = 25 ppm (2.88 mg as/kg bw/d) Field study: vineyards South Europe (Brown et al., 2007) Radio-trackers: Before treatment (34 birds), 10 days after treatment (19 birds). Focal species on vines: Black Redstart. Application rate: Dursban 480 EC. 2x 360 g as/ha. Summer application (11 and 27 June). Results: For 56 birds radio-tracked only 1 was dead after application, and there is no evidence that the death was related to treatment. No abnormal behaviour was observed. The foraging time spent on the crop was very low (90 th PT = 0.75, mean PT = 0.28) There is clear preference for off-crop land (low exposure scenario). Conclusion: 2 sequential applications of chlorpyrifos to vines at 360 g as/ha had no discernible short-term impact on the survival or behaviour of birds frequenting the vineyards. The mortality was not significantly increased but some uncertainties within the study were indicated. The conclusion in the meeting of experts was that the study is useful as additional information but is not an indication of low risk to birds. 10

11 Toxicity/exposure ratios for terrestrial vertebrates (Annex IIIA, points 10.1 and 10.3) Toxicity/exposure ratios for terrestrial vertebrates (Annex IIIA, points 10.1 and 10.3) from confirmatory data for birds and mammals- Acute Toxicological endpoint used for calculations is 13.3 mg as/kg. Application rate (kg as/ha) Crop Category (e.g. insectivorous bird) Vineyards Insectivorous bird-tier I Vineyards Insectivorous bird-tier II Vineyards Insectivorous bird-tier II Vineyards Insectivorous bird-tier I Vineyards Insectivorous bird-tier II Vineyards Insectivorous bird-tier I Vineyards Insectivorous birds- Tier II Time-scale TER Annex VI Trigger Acute 13.3 mg as/kg bw Acute 13.3 mg as/kg bw Acute 13.3 mg as/kg bw 1 10 Refined for measured residues accounting for dead arthropods TER = 2.1 Black Redstart (PD 50% foliagedwelling arthropods, 50% grounddwelling arthropods), and residue accounting for dead arthropods TER = Short-term Short-term Refined for measured residues TER = Long-term Long-term Black Redstart. PD: 50% grounddwelling arthropods, 50% foliagedwelling arthropods. Real residues accounting for dead arthropods, 5 PT = 0.75, FIR/bw= 0.82 TER = 6.7 Long-term Vineyards Earthworm-eating birds Vineyards Fish-eating birds-tier I Long -term

12 Application rate (kg as/ha) Crop Category (e.g. insectivorous bird) Time-scale TER Annex VI Trigger Vineyards Fish-eating birds-tier II Vineyards Small Herbivorous mammals-vole-tier I Vineyards Small Herbivorous mammals-vole-tier II Vineyards Medium herbivorous mammals-rabbit-tier II Vineyards Omnivorous mammals-wood mouse-tier II Vineyards Insectivorous mammals-common shrew-tier II Vineyards Small herbivorous mammals-vole-tier I Vineyards Medium herbivorous mammals-rabbit-tier II Vineyards Omnivorous mammals-wood mouse-tier II Vineyards Insectivorous mammals-common shrew-tier II Vineyards Earthworm-eating mammals-tier Vineyards Earthworm-eating mammals-tier II Vineyards Fish-eating mammals- Tier I Vineyards Fish-eating mammals- Tier II Long-term Refined for buffer zone (PECsw of 10 times EAC of 0.1 μg as/l) TERlt = 10 5 Acute Acute Refined using specific residues TER = Acute Refined using 10 specific residues TER = 11.9 Acute Refined using 10 specific residues TER = 10.6 Acute Refined using 10 specific residues TER = 69 Long-term Long-term Long-term Long-term Long-term Long-term Refined for measured residues (BCF = 1.26) TER = Long -term Long -term Refined for buffer zone (PECsw of 10 times EAC of 0.1 μg as/l) TER =

13 ABBREVIATIONS µg microgram a.s. active substance AF assessment factor AV avoidance factor BCF bioconcentration factor bw body weight CAS Chemical Abstract Service d day DM dry matter DT 50 period required for 50 percent disappearance (define method of estimation) DT 90 period required for 90 percent disappearance (define method of estimation) dw dry weight EAC environmentally acceptable concentration EbC 50 effective concentration (biomass) EC 50 effective concentration EEC European Economic Community ER 50 emergence rate/effective rate, median ErC 50 effective concentration (growth rate) EU European Union FAO Food and Agriculture Organisation of the United Nations FIR Food intake rate FOCUS Forum for the Co-ordination of Pesticide Fate Models and their Use g gram GAP good agricultural practice GM geometric mean GS growth stage h hour(s) ha hectare L litre LD 50 lethal dose, median; dosis letalis media LOAEL lowest observable adverse effect level LOD limit of detection m metre MAF multiple application factor mg milligram ml millilitre mm millimetre MTD maximum tolerated dose MWHC maximum water holding capacity ng nanogram NOAEC no observed adverse effect concentration NOAEL no observed adverse effect level NOEC no observed effect concentration NOEL no observed effect level OM organic matter content Pa Pascal PD proportion of different food types PEC predicted environmental concentration PEC air predicted environmental concentration in air PEC gw predicted environmental concentration in ground water PEC sed predicted environmental concentration in sediment predicted environmental concentration in soil PEC soil 13

14 PEC sw predicted environmental concentration in surface water ph ph-value PHI pre-harvest interval pk a negative logarithm (to the base 10) of the dissociation constant P ow partition coefficient between n-octanol and water ppm parts per million (10-6 ) ppp plant protection product PT proportion of diet obtained in the treated area r 2 coefficient of determination RUD residue per unit dose SD standard deviation SFO single first-order SSD species sensitivity distribution t 1/2 half-life (define method of estimation) TER toxicity exposure ratio TER A toxicity exposure ratio for acute exposure TER LT toxicity exposure ratio following chronic exposure TER ST toxicity exposure ratio following repeated exposure TLV threshold limit value TRR total radioactive residue TWA time weighted average UV ultraviolet W/S water/sediment w/v weight per volume w/w weight per weight WHO World Health Organisation wk week yr year 14