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Azinphos-methyl
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 86-50-0
NIOSH REL: 0.2 mg/m3 TWA [skin]
Current OSHA PEL: 0.2 mg/m3 TWA [skin]
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 0.2 mg/m3 TWA [skin]
Description of substance: Colorless crystals or a brown, waxy solid.
LEL: Noncombustible Solid
Original (SCP) IDLH: 20 mg/m3
Basis for original (SCP) IDLH: Because no useful data on acute inhalation toxicity are available concerning the toxic effects produced by azinphos-methyl, the chosen IDLH has been based on an analogy with parathion, which has an IDLH of 20 mg/m3.
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA
Lethal concentration data:
| Species | Reference | LC50 | LCLo | Time | Adjusted 0.5-hr LC (CF) | Derived Value |
|---|---|---|---|---|---|---|
| Rat | Newell and Dilley 1978 | 69 mg/m3 | —– | 1 hr | 86 mg/m3 (1.25) | 8.6 mg/m3 |
| Rat | Sanderson 1961 | 79 mg/m3 | —– | 1 hr | 99 mg/m3 (1.25) | 9.9 mg/m3 |
Lethal dose data:
| Species | Reference | Route | LD50(mg/kg) | LDLo(mg/kg) | Adjusted LD | Derived Value |
|---|---|---|---|---|---|---|
| Rat | Dubois et al. 1957 | oral | 16 | —– | 115 mg/m3 | 12 mg/m3 |
| G. pig | Dubois et al. 1957 | oral | 80 | —– | 560 mg/m3 | 56 mg/m3 |
| Rat | Gaines 1960 | oral | 11 | —– | 77 mg/m3 | 7.7 mg/m3 |
| Rat | Gaines 1960 | oral | 13 | —– | 91 mg/m3 | 9.1 mg/m3 |
| Mouse | Murphy et al. 1976 | oral | 8.6 | —– | 60 mg/m3 | 6.0 mg/m3 |
| Rat | Sanderson 1961 | oral | 7 | —– | 49 mg/m3 | 4.9 mg/m3 |
| Mouse | Sato 1959 | oral | 8 | —– | 56 mg/m3 | 5.6 mg/m3 |
| Dog | Worthing 1991 | oral | 10 | —– | 70 mg/m3 | 7.0 mg/m3v |
Human data: Eight workers exposed to concentrations as high as 9.6 mg/m3 (no time period given) showed no signs or symptoms of illness [Jegler 1964].
| Revised IDLH: 10 mg/m3Basis for revised IDLH: The revised IDLH for azinphos-methyl is 10 mg/m3 based on acute inhalation toxicity data in humans [Jegler 1964] and animals [Newell and Dilley 1978; Sanderson 1961]. This may be a conservative value due to the lack of acute toxicity data for workers exposed to concentrations above 10 mg/m3. |
REFERENCES:
- DuBois KP, Thursh DR, Murphy SD [1957]. Studies on the toxicity and pharmacologic actions of the dimethoxyl ester of benzotriazine dithiophosphoric acid. J Pharmacol Exp Ther 119:208-218.
- Gaines TB [1960]. Acute toxicity of pesticides in rats. Toxicol Appl Pharmacol 2:88-99.
- Jegler Z [1964]. Exposure to guthion during spraying and formulating. Arch Environ Health 8:565-569.
- Murphy SD, Cheever KL, Chow AYK, Brewster M [1976]. Organophosphate insecticide potentiation by carboxylesterase inhibitors. Proc Eur Soc Toxicol 17:292-300.
- Newell GW, Dilley JV [1978]. Teratology and acute toxicology of selected chemical pesticides administered by inhalation. Menlo Park, CA: Stanford Research Institute, p. 18. Prepared for Health Effects Research Laboratory, U.S. EPA, EPA-60011-78-003.
- Sanderson DM [1961]. Treatment of poisoning by anticholinesterase insecticides in the rat. J Pharm Pharmacol 13:435-442.
- Sato I [1959]. Studies on organic phosphorus gusathion and phosdrin. I. The toxicity of gusathion and phosdrin. Kuma Med J 12(1):312-317.
- Worthing CR, ed. [1991]. Azinphos-methyl. In: The pesticide manual: a world compendium. 9th ed. Old Woking, Surrey, England: Unwin Brothers Limited, p. 46.