Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content


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

CAS number: 63–25–2

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: White or gray, odorless solid.

LEL: . . Noncombustible Solid

Original (SCP) IDLH: 600 mg/m3

Basis for original (SCP) IDLH: Because no useful data on acute inhalation toxicity are available for carbaryl, the chosen IDLH is based on the rat oral LD50 of 89 mg/kg [Boyd and Taylor 1971 cited by NIOSH 1974]. In addition, ACGIH [1971] reported that female rats may occasionally be killed by a single oral dose of 100 mg/kg [Gaines 1969].

Short-term exposure guidelines: None developed


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
RabbitG. pig







AAPCO 1966Benson and Dorough 1984

Buck 1979

Gaines 1960

Gaines 1960

Gig Sanit 1967

Stevens et al. 1972

Weiss and Orzel 1967






















4,970 mg/m31,750 mg/m3

5,313 mg/m3

5,950 mg/m3

3,500 mg/m3

1,050 mg/m3

896 mg/m3

1,610 mg/m3

497 mg/m3175 mg/m3

531 mg/m3

595 mg/m3

350 mg/m3

105 mg/m3

90 mg/m3

161 mg/m3


Other animal data: A concentration of about 75 mg/m3 produced typical poisoning in dogs within 5 hours [Carpenter et al. 1961].

Human data: None relevant for use in determining the revised IDLH.

Revised IDLH: 100 mg/m3Basis for revised IDLH: The revised IDLH for carbaryl is 100 mg/m3 based on acute toxicity data in animals [Carpenter et al. 1961; Gig Sanit 1967; Stevens et al. 1972].



1. AAPCO [1966]. Pesticide chemicals official compendium. Topeka, KS: Association of American Pesticide Control Officials, Inc., p. 192.

2. ACGIH [1971]. Carbaryl (Sevin). In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 37-38.

3. Benson WH, Dorough HW [1984]. Comparative ester hydrolysis of carbaryl and ethiofencarb in four mammalian species. Pest Biochem Physiol 21:199-206.

4. Boyd EM, Taylor FI [1971]. Toxaphene toxicity in protein-deficient rats. Toxicol Appl Pharmacol 18:158-167.

5. Buck WB [1979]. Clinical toxicosis induced by insecticides. Vet Med Small Anim Clin 74:1119.

6. Carpenter CP, Weil CS, Palm PE, Woodside MW, Nair JH III, Smyth HF Jr [1961]. Mammalian toxicity of 1-naphthyl-N-methylcarbamate (Sevin insecticide). J Agri Food Chem 9(1):30-39.

7. Gaines TB [1960]. The acute toxicity of pesticides to rats. Toxicol Appl Pharmacol 2:88-99.

8. Gaines TB [1969]. Acute toxicity of pesticides. Toxicol Appl Pharmacol 14:515-534.

9. Gig Sanit [1967]; 32(4):29-33 (in Russian).

10. NIOSH [1974]. FC59500. Carbamic acid, methyl-, 1-naphthyl ester. In: The toxic substances list, 1974 ed. Rockville, MD: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 74-134, p. 182.

11. Stevens JT, Stitzel RE, McPhillips JJ [1972]. Effects of anticholinesterase insecticides on hepatic microsomal metabolism. J Pharmacol Exp Ther 181:576-583.

12. Weiss LH, Orzel RA [1967]. Some comparative toxicologic and pharmacologic effects of dimethyl sulfoxide as a pesticide solvent. Toxicol Appl Pharmacol 11:546-557.