May 1994

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

1,1-Dichloro-1-nitroethane

CAS number: 594–72–9

NIOSH REL: 2 ppm (10 mg/m³) TWA

Current OSHA PEL: 10 ppm (60 mg/m³) CEILING

1989 OSHA PEL: 2 ppm (10 mg/m³) TWA

1993-1994 ACGIH TLV: 2 ppm (12 mg/m³) TWA

Description of Substance: Colorless liquid with an unpleasant odor.

LEL:. . Unknown

Original (SCP) IDLH: 150 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the study by Machle et al. [1945] in which autopsies on animals exposed to over 170 ppm for over 30 minutes revealed pulmonary edema and hemorrhage, with damage to the heart, liver, and kidneys.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA

Lethal concentration data:

Species

Reference

LC₅₀

(ppm)

LC_Lo

(ppm)

Time

Adjusted 0.5-hr

LC (CF)

Derived

value

Rabbit

G. pig

Rabbit

G. pig

Rabbit

G. pig

Machle et al. 1945

170

-----

30 min

6 hr

18.75 hr

170 ppm (1.0)

223 ppm (2.3)

172 ppm (3.33)

17 ppm

22 ppm

17 ppm

Other animal data: Animals have tolerated 25 ppm for 204 hours [ Machle et al. 1945].

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

Revised IDLH: 25 ppm

Basis for revised IDLH: The revised IDLH for 1,1-dichloro-1-nitroethane is 25 ppm based on acute inhalation toxicity data in animals [Machle et al. 1945]. This may be a conservative value due to the lack of relevant acute toxicity data for workers.

REFERENCE:

1. Machle W, Scott EW, Treon JF, Heyroth FF, Kitzmiller KV [1945]. The physiological response of animals to certain chlorinated mononitroparaffins. J Ind Hyg Toxicol 27(4):95-102.