May 1994

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

Crag® herbicide

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

ACUTE TOXICITY DATA

Lethal dose data:

Species

Reference

Route

LD₅₀

(mg/kg)

LD_Lo

(mg/kg)

Adjusted LD

Derived value

Rat

Mammal

Carpenter et al. 1961

Gunther 1962

Sine 1991

oral

480

730

1,230

-----

3,360 mg/m³

5,110 mg/m³

8,610 mg/m³

336 mg/m³

511 mg/m³

861 mg/m³

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

Revised IDLH: 500 mg/m³

Basis 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.

REFERENCES:

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.