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Crag® herbicide

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

CAS number: 136–78–7

NIOSH REL: 10 mg/m3 (total dust) TWA, 5 mg/m3 (respirable dust) TWA

Current OSHA PEL: 15 mg/m3 (total dust) TWA, 5 mg/m3 (respirable dust) TWA

1989 OSHA PEL: 10 mg/m3 (total dust) TWA, 5 mg/m3 (respirable dust) TWA

1993-1994 ACGIH TLV: 10 mg/m3 TWA

Description of Substance: Colorless to white crystalline, odorless solid.

LEL: . . Noncombustible Solid

Original (SCP) IDLH: 5,000 mg/m3

Basis for original (SCP) IDLH: According to many sources, Crag® herbicide is not very toxic to mammals. Because no acute inhalation toxicity data are available, the chosen IDLH has been estimated from the rat oral LD50 of 730 mg/kg [Gunther 1962 cited by NIOSH 1976].

Short-term exposure guidelines: None developed


Lethal dose data:

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


Carpenter et al. 1961Gunther 1962

Sine 1991







3,360 mg/m35,110 mg/m3

8,610 mg/m3

336 mg/m3511 mg/m3

861 mg/m3


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

Revised IDLH: 500 mg/m3Basis for revised IDLH: No inhalation toxicity data are available on which to base an IDLH for Crag® herbicide. Therefore, the revised IDLH for Crag® herbicide is 500 mg/m3 based on acute oral toxicity data in animals [Carpenter et al. 1961; Gunther 1962; Sine 1991]. This may be a conservative value due to the lack of acute toxicity data for workers.



1. Carpenter CP, Weil CS, Smyth HF Jr. [1961]. Mammalian toxicity of sesone herbicide. J Agri Food Chem 9:382-385

2. Gunther FA, ed. [1962]. Residues of pesticides and other foreign chemicals in food and feeds. Vol. I. Secaucus, NJ: Springer Verlag New York, Inc., p. 18.

3. NIOSH [1976]. KK49000. Ethanol, 2-(2,4-dichlorophenoxy)-, hydrogen sulfate, sodium salt. In: Registry of toxic effects of chemical substances, 1976 ed. Cincinnati, OH: 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. 76-191, p. 503.

4. Sine C, ed. [1991]. Sesone. In: Farm chemicals handbook ’91, p. C273.