ETHOPROPHOS (149) EXPLANATION

1 35. ETHOPROPHOS (149). First draft prepared by Trijntje van der Velde-Koerts and Bernadette C. Ossendorp, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands EXPLANATION . ETHOPROPHOS , a nematicide and soil-insecticide, was evaluated for residues in 1984 and in 1987. The toxicology of ETHOPROPHOS was periodically reviewed by the 1999 JMPR. ETHOPROPHOS was listed as a priority compound under the periodic re-evaluation programme of the 30th Session of the CCPR. (ALINORM 99/24 App VII) for residue review by the 2001 JMPR. The manufacturer requested the postponement of the residue evaluation. The basic manufacturer supplied information on identity, metabolism and environmental fate, residue analysis, use pattern, residues resulting from supervised trials on strawberry, banana, cucumber, melon, pepper, tomato, potato, sweet potato and sugar cane, fate of residues during storage and in processing, residues in food in commerce or at consumption and national maximum residue limits.

2 IDENTIT. ISO common name: ETHOPROPHOS Chemical name IUPAC: O-ethyl S,S-dipropyl phosphorodithioate CAS: O-ethyl S,S-dipropyl phosphorodithioate CAS Registry No: 13194-48-4. CIPAC No: 218. Synonyms and trade names: S,S-dipropyl O-ethyl phosphorodithioate;. prophos; ethoprop;. Mocap; VC9-104; ENT-27318; AE F034142. Structural formula: established by IR, 1H-NMR, 13C-NMR, 31P-NMR, APCI-MS (+/-). and UV-VIS (according to OECD 101) (Boeuf et al., 2000). O. P S. O S. Molecular formula: C8H19O2PS2 (Boeuf et al., 2000). Molecular weight: (Boeuf et al., 2000). Physical and chemical properties Pure active ingredient Physical and chemical properties were determined with the pure active ingredient, unless specified otherwise.

3 Property Description or result Method(s). (References). Minimum purity 980 g/kg (Barriere, 2004a). Appearance colourless clear liquid, odour not assessed (Ristorcelli, 2001a). 36 ethroprophos Property Description or result Method(s). (References). Vapour pressure 78 mPa at 20 C OPPTS 123 mPa at 25 C 92/69/EC A4. calculated from Clausius-Clapeyron relationship from OECD 104. measurements at C Knudsen effusion method (Ristorcelli, 2001b). Melting/freezing below -70 C ( K) OPPTS point 92/69/EC A1. differential scanning calorimetry (Ristorcelli, 2001a). Octanol/water Log Kow = (95% confidence interval ), OPPTS partition coefficient temperature not stated 92/69/EC A8.

4 Kow is not pH-dependent OECD 117. HPLC method (Ristorcelli, 2001d). Water solubility g/L (RSD ), 20 C; OPPTS solubility not pH-dependent, 92/69/EC A6. determined from pH 4 to 9 OECD 105. flask method (Ristorcelli, 2001c). Solubility in purity (technical grade) OPPTS organic solvents > 500 g/L at 20 C in acetone; acetonitrile; 1,2 dichloroethane; 92/69/EC A6. ethyl acetate; n-hexane; methanol; n-octanol; toluene OECD 105. flask method (Ristorcelli, 2001c). Relative density , OPPTS (D204) measured at C instead of 20 C 92/69/EC A3. oscillating densitimeter (Ristorcelli, 2001a). Hydrolysis in - Chemical and radiochem. purity >98% Fed. Reg. 43, (132) 29717.

5 Aqueous solution, - Stability tested over 6 week period at 2 and 200 mg/l at pH 3, (Norris, 1983), non-GLP. study 1 6, 9, in the dark with radio-label on C-1 carbon of the propyl group. Half-life 28-36 weeks at pH3, 20 C. 33-39 weeks at pH 6, 20 C. 39-44 days at pH 9, 20 C. 16-21 weeks at pH 3, 35 C. 14-16 weeks at pH 6, 35 C. 10-14 days at pH 9, 35 C. - Identified degradation product O-ethyl S-propyl phosphorothioic acid (mP). - Radioactivity was partly lost (up to 40% at 35 C at pH 9 at 7- 42 days) as unknown volatile compounds. Hydrolysis in -Radiochem. purity >98%, chemical purity not stated US EPA 161-1. aqueous solution, - Stability tested over 30 day period at 10 mg/l at pH 5, 7, 9, in (Das, 1989).

6 Study 2 the dark, with 1-ethyl-14C radiolabel at 25 1 C. -Stable at pH5 and 7, 25 C;. -Half-life 83 days at pH =9, 25 C;. -Identified degradation products ethyl alcohol and S,S-dipropyl phosphorodithioic acid (mK). -Total 14C recovery >99%. Hydrolysis in -Radiochem. purity >98%, chemical purity not stated OECD 111. aqueous solution, -Stability tested over a 20 day period at 10 mg/l at pH 4, in the (Maurer, 2002). study 3 dark, with radio-label on C-1 carbon of the propyl group at 60, 70 and 80 C 1 C. - Half-life 10 days at 60 C;. Half-life days at 70 C. Half-life days at 80 C. Stable at pH 4 at 20 C, half-life >365 days, calculated from Arrhenius plot.

7 - Identified degradation product S,S-dipropyl phosphorodithioic acid (mK). - Total 14C recovery >93%. ethroprophos 37. Property Description or result Method(s). (References). Photolysis in -Radiochem. purity , chemical purity > US EPA 161-2. aqueous solution; - Stability tested over 30 day period at 22 mg/l at pH 7, with 1- (Carpenter, 1989). study 1 ethyl-14C radiolabel at 25 1 C, continuous radiation with xenon-arc lamp at one-half the intensity of sun light. - Stable with or without sensitizer (1% v/v acetone);. half-life could not be calculated - Total 14C recovery > 98%. Photolysis in -Radiochem. purity , chemical purity not stated US EPA 161-2.

8 Aqueous solution; - Stability tested over 30 day period at 15 mg/l at pH 7, with 1- (Gorman, 1995). study 2 ethyl-14C radiolabel at 25 1 C, continuous radiation with xenon-arc lamp at one-half the intensity of sun light. - Half-life 122 days without senzitiser Half-life 104 days with senzitizer (1% v/v acetone). - Total 14C recovery > 98%. Dissociation constant purity (technical grade); OPPTS ;. pH of a 1% (w/v) suspension in water, at 23 C = (Bascou, 2001). ETHOPROPHOS does not dissociate. Technical material Property Result Method(s). (references). Minimum purity 940 g/kg (Barriere, 2004a). Main impurities no data provided Appearance colourless, clear liquid, odour not assessed (Ristorcelli, 2001a).

9 Relative density (D204) , OPPTS measured at C in stead of 20 C 92/69/EC A3. oscillating densitimeter;. (Ristorcelli, 2001a). Freezing point below -70 C ( K) OPPTS 92/69/EC A1. differential scanning calorimetry (Ristorcelli, 2001a). Stability Techical material was placed in 3 different EPA 40 CFR , D 63-17. kind of packaging containers. No (Eubanks, 1991). significant decrease was observed after a 1. year storage period at ambient temperature (23-25 C) and 50% relative humidity. Formulations ETHOPROPHOS end-use products are formulated mainly as granulates (GR 50, 100, 150, 200 g ai/kg), or as emulsifiable concentrates (EC, , , 200, 720 g ai/l). Ethophrophos can also be formulated as microgranulate (MG, 100, 200 g ai/kg) or as an emulsifiable gel packaged in a water-soluble bag (gel, 720 g ai/l).

10 FAO specifications for technical and formulated ETHOPROPHOS have not been published. Abbreviations and code names Table 1. Metabolite and degradation product codes used in the present review. Code used Code used in Name Found in here study reports mA M1 O-ethyl S-propyl hydrogen phosphorothioate rat/rabbit;. AE0592496 (O-ethyl S-propyl phosphorothioate) goat?; hen?;. 38 ethroprophos Code used Code used in Name Found in here study reports plant;. aerobic soil mB propanethiol volatile mC dipropyl disulfide plant;. not found in rat;. not tested in livestock not found in aerobic soil mD ethyl propyl sulfide plant, not found in rat;. not tested in livestock not found in aerobic soil mE ethyl propyl sulfoxide plant, aerobic soil not found in rat, not tested in livestock mF ethyl propyl sulfone plant, aerobic soil not found in rat, not tested in livestock mG methyl propyl sulfide plant?