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May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)


CAS number: 7786–34–7

NIOSH REL: 0.01 ppm (0.1 mg/m3) TWA, 0.03 ppm (0.3 mg/m3) STEL [skin]

Current OSHA PEL: 0.1 mg/m3 TWA [skin]

1989 OSHA PEL: 0.01 ppm (0.1 mg/m3) TWA, 0.03 ppm (0.3 mg/m3) STEL [skin]

1993-1994 ACGIH TLV: 0.01 ppm (0.92 mg/m3) TWA,

0.03 ppm (0.27 mg/m3) STEL [skin]

Description of substance: Pale-yellow to orange liquid with a weak odor.

LEL: . . Unknown

Original (SCP) IDLH: 4 ppm

Basis for original (SCP) IDLH: No useful data on acute inhalation toxicity are available on which to base the IDLH for Phosdrin. The chosen IDLH has been estimated from the male rat oral LD50 of 6 to 7 mg/kg [Shell 1956 cited by ACGIH 1971]. [Note: A concentration of 4 ppm phosdrin is equivalent to about 40 mg/m3.]

Short-term exposure guidelines: None developed


Lethal concentration data:


SpeciesReferenceLC50 (ppm)LCLo (ppm)TimeAdjusted 0.5-hr LC (CF)Derived value
RatKodama et al. 1954 14-----1 hr18 ppm (1.25)1.8 ppm

Lethal dose data:


SpeciesReferenceRouteLD50 (mg/kg)LDLo (mg/kg)Adjusted LDDerived value



Kenaga 1979

Kodama et al. 1954

Shell 1956










2.3 ppm

3.0 ppm

4.5-5.3 ppm

0.2 ppm

0.3 ppm

0.5 ppm

Human data: A dose of 2.5 mg/day for 27 days caused a 25% decrease in red blood cell cholinesterase [Rider et al. 1975]. [Note: An oral dose of 2.5 mg/day for 27 days is equivalent to a worker being exposed to about 5 ppm for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]


Revised IDLH: 4 ppm [Unchanged]

Basis for revised IDLH: Based on acute toxicity data in humans [Rider et al. 1975], the original IDLH for phosdrin (4 ppm) is not being revised at this time.


1. ACGIH [1971]. Phosdrin (mevinphos). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 208.

2. Kenaga EE [1979]. Acute and chronic toxicity of 75 pesticides to various animal species. Down to Earth 35:25-31.

3. Kodama J, Morse MS, Anderson HH, Dunlap MK, Hines CH [1954]. Comparative toxicity of two vinyl-substituted phosphates. AMA Arch Ind Hyg Occup Med 9:45-61.

4. Rider JA, Puletti EJ, Swader JI [1975]. The minimal oral toxicity level for mevinphos in man. Toxicol Appl Pharmacol 32(10):97-100.

5. Shell [1956]. Personal communication to ACGIH from the Shell Chemical Corporation, August 31, 1956. [From ACGIH [1991]. Phosdrin. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 1044-1046.]

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