DELTAMETHRIN (135) First draft prepared by Dugald ...

1 167. DELTAMETHRIN (135). First draft prepared by Dugald maclachlan , department of agriculture , forestry and fisheries , australia EXPLANATION. DELTAMETHRIN has been evaluated several times since the initial evaluation in 1980. It was last evaluated in 1992 for residues and in 2000 for toxicology. At the 30th Session of the CCPR, the Committee noted that DELTAMETHRIN was on the agenda of the 52nd JECFA (1999). At the 31st Session of the CCPR, the committee noted the MRLs estimated by JECFA for veterinary uses would be circulated for comments at step 3, through CL-RVDF, governments were invited to co-ordinate their comments at the national level. DELTAMETHRIN was identified as a priority compound under the Periodic Re-evaluation Program at the 29th Session of the CCPR and scheduled for the 2002 JMPR.

2 Data to support the existing CXLs and other critical data required for the estimation of MRLs have been provided by the company. The governments of australia , The Netherlands, Poland and Germany have submitted information on national GAP and/or residue data. IDENTITY. ISO Common name: DELTAMETHRIN Chemical name: IUPAC: (S)- -cyano-3-phenoxybenzyl (1R,3R)-3-(2,2-dibromovinyl)-2,2- dimethylcyclopropanecarboxylate CA: [1R-[1 (S*),3 ]]-cyano(3-phenoxyphenyl)methyl 3-(2,2-dibromoethenyl)-2,2- dimethylcyclopropanecarboxylate CAS No.: [52918-63-5]. CIPAC No.: 333. Synonyms/trade names: decamethrin, AE F032640, RU 22974, HOE 032640, NRDC 161, FMC. 45498. Structural formula: O. Br C CH C O CN. Br C O. H. H H. CH CH. 3 3. Molecular formula: C22H19Br2NO3. Molecular weight: 168 DELTAMETHRIN Physical and chemical properties Pure active ingredient Appearance: off-white solid powder (technical grade) (Thomas and Sweetapple, 1990).

3 Melting point: 100-102 C (373-375 K), (technical grade) (Sweetapple, 1990). Partition coefficient, log Pow: at 25 C, pH 7,6 (not pH dependent) (Yoder, 1991a). Hydrolysis: pH 5 (buffered): negligible (Smith, 1990a). pH 7 (buffered): negligible (Smith, 1990a). pH 9 (buffered): half-life days (mean value) (Smith, 1990a). pH 8 (buffered): half-life 31 days (Maurer and Sch fer, 2002). Photolysis: half-life 48 days. Quantum yield in wavelength range 290-385 nm was calculated to be 10-4 (C008524). Dissociation constant: DELTAMETHRIN is neither acid nor alkaline and dissociation is not expected to occur at environmentally relevant pH. Technical material Minimum purity: 980 g/kg (technical grade). Vapour pressure: 10-8 Pa at 25 C. 10-8 Pa at 35 C. 10-7 Pa at 45 C (Yoder, 1991b).

4 Volatility: Henry's law constant: 10-2 based on a water solubility of g as/l and a vapour pressure of 10-8, both at 25 C (A70747) (Grelet, 1995). Appearance: off-white solid powder (technical grade). Odour: odourless Density: g/cm3. Table 1. Solubility of DELTAMETHRIN . Solvent Solubility Water: g/l at 25 C (A26313, C009221) (Jamet and Hascoet, 1977; M hlberger and Jordan, 2000a). Organic Solvents: Results measured at 20 C (A45109, C009220) (Yoder 1990, M hlberger and Jordan 2000b). Cyclohexane 1-10%. benzene and toluene 10-50%. Xylenes 18 g/100ml at 25 C. 1,1,1-trichloroethane 10-50%. iso-propanol <1%. Ethanol 1-10%. n-octanol g/100ml at 25 C. Glycerol <1%. Acetone 10-50%. DELTAMETHRIN 169. Solvent Solubility Cyclohexanone >50%. ethyl acetate 10-50%.

5 Thermal stability: stable to 270 C (Sanders, 1991). Flammability: not flammable or auto-flammable (Hoffmann, 1996a,b). Oxidizing potential: not oxidizing (Smeykal, 2000). Explosivity: not explosive (Smeykal, 2000). Formulations The following Table includes the major formulations developed for DELTAMETHRIN crop and animal health uses around the world. Table 2. DELTAMETHRIN formulations and codes. Type Code number Concentration agriculture Emulsifiable concentrate (EC) AE F032640 00 EC03 BO 25 g/l Emulsifiable concentrate (EC) AE F032640 00 EC11 A3 100 g/l Emulsifiable concentrate (EC) AEF 032640 00 EC02 A8 15 g/l Emulsion, oil in water (EW) AE F032640 00 EW01 B1 15 g/l Suspension concentrate (SC) AE F032640 00 SC02 50 g/l or 25 g/l Ultra low volume (UL) AE F032640 00 UV01 5 g/l Emulsifiable granule (EG) AE F032640 00 EG06 A1 60 g/kg Tablet (TB) AE F032640 00 TB25 A1 250 g/kg Animal health Dip, spray AE F032640 00 WP05 A2 50 g/l Pour-on g/l METABOLISM AND ENVIRONMENTAL FATE.

6 Animal metabolism Metabolism studies on rats, goats and hens with [14C] DELTAMETHRIN and [13,14C] DELTAMETHRIN were made available to the Meeting. The metabolism of laboratory animals was reported by the 2000 JMPR as part of a review of the toxicology of DELTAMETHRIN and is qualitatively the same as for farm animals. To carry out various metabolism, degradation and toxicological or ecotoxicological studies, the DELTAMETHRIN molecule has been labelled on various carbon atoms: [14C-dibromovinyl] DELTAMETHRIN labelled on Cv 14. [ C-benzyl] DELTAMETHRIN labelled on C . [14C-cyano] DELTAMETHRIN labelled on CN. [14C-gem-dimethyl] DELTAMETHRIN labelled on (CH3)2. 170 DELTAMETHRIN 14C . 14Cv 5. 4'. Br 3R 1R 3. O S. * * O 2'. Br 2. O CN. * * *. 14CN. 14C gem-dimethyl The following Table shows the main degradation products of DELTAMETHRIN and the abbreviations used for some metabolites.

7 Table 3. Relationship between abbreviated, common and chemical names, company codes and structural formulae. Common name or Roussel Chemical name (generally CAS) Structural formula abbreviation Uclaf code (S)- -cyano-3-phenoxybenzyl (1R,3R)-3- Br O CN. DELTAMETHRIN RU 22974 (2,2-dibromovinyl)-2,2- O. dimethylcyclopropanecarboxylate Br O. (R)- -cyano-3-phenoxybenzyl (1R,3R)-3- Br O CN. (2,2-dibromovinyl)-2,2- O. -R- DELTAMETHRIN RU 23938. dimethylcyclopropanecarboxylate Br O. [1R-[1 (S*),3 ]]-3-(2,2-dibromoethenyl)- O CN. trans- RU 26979 2,2-dimethyl-cyclopropanecarboxylic O. Br DELTAMETHRIN acid, cyano(3-phenoxyphenyl)methyl O. ester Br [1R-[1 (S*),3 ]]-3-(2,2- O NH2. O. DELTAMETHRIN RU 38250 dibromoethenyl)-2,2-dimethyl- Br amide cyclopropanecarboxylic acid, 2-amino- O.

8 Br O. 2oxo-1-(3-(phenoxyphenyl)ethyl ester [1R-[1 (S*),3 ]]-3-(2,2- Br O CN OH. 2-OH- RU 51713 dibromoethenyl)-2,2-dimethyl- O. DELTAMETHRIN cyclopropanecarboxylic acid, cyano(3-(2- Br O. hydroxyphenoxyphenyl)methyl ester DELTAMETHRIN 171. Common name or Roussel Chemical name (generally CAS) Structural formula abbreviation Uclaf code [1R-[1 (S*),3 ]]-3-(2,2- Br O CN. 4-OH- RU 53605 dibromoethenyl)-2,2-dimethyl- O. DELTAMETHRIN cyclopropanecarboxylic acid, cyano(3-(4- Br O. hydroxyphenoxyphenyl)methyl ester OH. 3-phenoxybenzaldehyde H. mPB aldehyde RU 26684 O. O. 3-phenoxybenzoic acid OH. mPB acid RU 50293 O. O. 3-phenoxybenzenemethanol O. HO. mPB alcohol RU 27330. (1R-cis)-3-(2,2-dibromoethenyl)-2,2- Br O. dimethylcyclopropanecarboxylic acid (cis) Br2CA RU 23441 OH.)))

9 Br (1R-trans)-3-(2,2-dibromoethenyl)-2,2- Br dimethylcyclopropanecarboxylic acid (trans) Br2CA RU 28302 Br OH. O. 3-(2-hydroxyphenoxy)benzoic acid O OH. O. 2'OH mPB acid RU 50961 HO. 3-(4-hydroxyphenoxy)benzoic acid O. O. 4'OH mPB acid RU 46606 HO. OH. 3-(4-hydroxyphenoxy)benzenemethanol O. HO. 4'OH mPB RU 46605. OH. alcohol DELTAMETHRIN is the [1R,cis; -S]-isomer of 8 stereoisomeric esters derived from esterification of the dibromo analogue of chrysanthemic acid, 3-(2,2-dibromovinyl)-2,2- dimethylcyclopropanecarboxylic acid (Br2CA) with -cyano-3-phenoxybenzyl alcohol. Lactating cows. Akhtar et al. (1986) dosed a lactating dairy Holstein 557 kg bw and an Ayrshire 504. kg bw cow with [14C] DELTAMETHRIN (gem-dimethyl or benzyl) at 10 mg/kg bw/day for 3 consecutive days.

10 Urine and faeces were collected for each 24-hour period and milk twice daily. The animals were slaughtered 24 hours after the last dose. Radioactivity in all samples was quantified and characterized by TLC and GC. DELTAMETHRIN appeared to be poorly absorbed and mainly eliminated in the faeces (cumulative total 36-43% of the administered dose) within 24 hours of the last dose as DELTAMETHRIN (s); 78-82% of 172 DELTAMETHRIN the 14C in faeces. The cumulative total for elimination in the urine until 24 hours after the last dose was only 4-6 % of the administered 14C, and % was secreted in the milk. Total deltamethrins were also the major identifiable products in milk ( mg/kg). The radiocarbon content in various tissues was generally very low (< mg/kg DELTAMETHRIN equivalents).