Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)

Azinphos-methyl

IDLH Documentation

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/m3

Basis 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.

Go back to the Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)

This page was last updated 8/16/96:
Go back to the NIOSH home page

or to the CDC home page.