Acetylene tetrabromide

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

CAS number: 79-27-6

NIOSH REL: The 1989 OSHA PEL may not be protective to workers.

Current OSHA PEL: 1 ppm (14 mg/m3) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 1 ppm (14 mg/m3) TWA

Description of substance: Pale-yellow liquid with a pungent odor similar to camphor or iodoform.

LEL: Noncombustible Liquid

Original (SCP) IDLH: 10 ppm

Basis for original (SCP) IDLH: Van Haaften [1969] reported that a chemist who had been exposed to 1 to 2 ppm for 7.5 hours, with only a single 10-minute exposure at 16 ppm, almost died from liver damage. Because the TLV is 1 ppm [ACGIH 1976], it is assumed that exposure to 1 to 2 ppm would be a safe concentration for the 7.5 hours the worker was exposed. Therefore, the injury must have been produced by the 10-minute exposure to 16 ppm, and the IDLH would be expected to fall between 2 ppm and 15 ppm. For this draft technical standard, an IDLH of 10 ppm is assumed. This is an extremely toxic substance.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hr LC (CF) Derived Value
Rat Izmerov et al. 1982 38 ----- 4 hr 76 ppm (2.0) 7.6 ppm

Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived Value
G. pig Gray 1950 oral 400 ----- 195 ppm 20 ppm
Rabbit Gray 1950 oral 400 ----- 195 ppm 20 ppm
Mouse Izmerov et al.1982 oral 269 ----- 131 ppm 13 ppm
Rat Paustovskaya et al. 1967 oral 1,200 ----- 585 ppm 59 ppm

Human data: Severe acute intoxication was reported in a chemist after exposure to 16 ppm for about 10 minutes and to 1 to 2 ppm for most of the day [Van Haaften 1969].

Revised IDLH: 8 ppm

Basis for revised IDLH: The revised IDLH for acetylene tetrabromide is 8 ppm based on acute inhalation toxicity data in animals [Izmerov et al. 1982].


  1. ACGIH [1976]. TLVs, Threshold limit values for chemical substances and physical agents in the workroom environment with intended changes for 1976. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 9.
  2. Gray MG [1950]. Effect of exposure to the vapors of tetrabromoethane (acetylene tetrabromide). AMA Arch Ind Hyg Occup Med 2:407-419.
  3. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 107.
  4. Paustovskaya VV, et al. [1967]. Effect of tetrabromomethane on the parenchymatous organs in experimental conditions. Med Pr 3:80-83 (in Polish).
  5. Van Haaften AB [1969]. Acute tetrabromoethane (acetylene tetrabromide) intoxication in man. Am Ind Hyg Assoc J 30:251-256.
Page last reviewed: December 4, 2014