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

CAS number: 83-79-4

NIOSH REL: 5 mg/m3 TWA

Current OSHA PEL: 5 mg/m3 TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 5 mg/m3 TWA

Description of substance: Colorless to red, odorless, crystalline solid.

LEL: . . Unknown

Original (SCP) IDLH*: Unknown [*Note: “Effective” IDLH = 5,000 mg/m3 — see discussion below.]

Basis for original (SCP) IDLH: ACGIH [1971] reported that Lehman [1949], on the basis of his own work and a literature survey, estimated the fatal human oral dose to be about 200 grams. Accordingly, this is a relatively nontoxic compound for humans, and thus respirators have been assigned based on the assigned protection factor afforded by each device up to 1,000 ´ the OSHA PEL of 5 mg/m3 (i.e., 5,000 mg/m3); only the “most protective” respirators are permitted for use in concentrations exceeding 5,000 mg/m3.

Short-term exposure guidelines: None developed


Lethal dose data:

Species Reference Route LD50




Adjusted LD Derived value
Rat Kenaga 1979 oral 60 ----- 420 mg/m3 42 mg/m3
Rat Lehman 1951 oral 132 ----- 924 mg/m3 92 mg/m3
Rat Lightbody & Matthews 1936 oral 25 ----- 175 mg/m3 18 mg/m3
Mouse Soloway 1976 oral 2.8 ----- 20 mg/m3 2.0 mg/m3

Human data: The fatal oral dose has been reported to be 200 grams [Lehman 1949]. [Note: An oral dose of 200 grams is equivalent to a worker being exposed to about 130,000 mg/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 2,500 mg/m3

Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for rotenone. Therefore, the revised IDLH for rotenone is 2,500 mg/m3 based on acute oral toxicity data in humans [Lehman 1949] and being 500 times the NIOSH REL and OSHA PEL (500 is an assigned protection factor for respirators and was used arbitrarily during the Standards Completion Program for deciding when the "most protective" respirators should be used for particulates).


1. ACGIH [1971]. Rotenone (commercial). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 224.

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

3. Lehman AJ [1949]. Pharmacological considerations of insecticides. Q Bulletin Assoc Food Drug Off U.S. 13(2):65-70.

4. Lehman AJ [1951]. Chemicals in foods: a report to the Association of Food and drug Officials on current developments. Part II. Pesticides. Section I. Introduction. Q Bulletin Assoc Food Drug Off U.S. 15(4):122-123.

5. Lightbody DH, Matthews JA [1936]. Toxicology of rotenone. Ind Eng Chem 28:809-811.

6. Soloway SB [1976]. Naturally occurring insecticides. Environ Health Perspect 14:109-117.

Page last reviewed: December 4, 2014