1,1­Dichloroethane

IDLH Documentation

CAS number: 75­34­3

NIOSH REL: 100 ppm (400 mg/m3) TWA

Current OSHA PEL: 100 ppm (400 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 100 ppm (400 mg/m3) TWA

Description of Substance: Colorless, oily liquid with a chloroform­like odor.

LEL:. . 5.4% (10% LEL, 5,400 ppm)

Original (SCP) IDLH: 4,000 ppm

Basis for original (SCP) IDLH: Patty [1963] reported that rats survived 8­hour exposures to 4,000 ppm, but died at 16,000 ppm [Smyth 1956]. However, 16,000 ppm has not been chosen as the IDLH because Kirk­Othmer [1964] indicated that 1,1­dichloroethane causes narcosis. For this draft technical standard, 4,000 ppm is chosen as the IDLH.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:


Species

Reference
LC50

(ppm)
LCLo

(ppm)

Time
Adjusted 0.5-hr

LC (CF)
Derived

value
Rat

Mouse

Rat
Carpenter et al. 1949

Mueller 1925

Smyth 1956
-----

-----

-----
16,000

17,300

16,000
4 hr

2 hr

8 hr
32,000 ppm (2.0)

27,680 ppm (1.6)

40,000 ppm (2.5)
3,200 ppm

2,768 ppm

4,000 ppm


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

Revised IDLH: 3,000 ppm

Basis for revised IDLH: The revised IDLH for 1,1­dichloroethane is 3,000 ppm based on acute inhalation toxicity data in animals [Carpenter et al. 1949; Mueller 1925].


REFERENCES:

1. Carpenter CP, Smyth HF Jr, Pozzani UC [1949]. The assay of acute vapor toxicity, and the grading and interpretation of results on 96 chemical compounds. J Ind Hyg Toxicol 31:343­346.

2. Kirk­Othmer [1964]. Encyclopedia of chemical technology. 2nd ed. New York, NY: John Wiley & Sons, Inc. 5:92­98.

3. Mueller J [1925]. Comparative investigations on the anesthetic and toxic effects of some halogenated hydrocarbons. Arch Exp Pathol Pharmakol 109:276­294 (in German). [From ACGIH [1991]. 1,1­Dichloroethane. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 425­428.]

4. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., pp. 1279­1280.

5. Smyth HF Jr [1956]. Improved communication: hygienic standards for daily inhalation. Am Ind Hyg Assoc Q 17(2):129­185.

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