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May 1994

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


CAS number: 127–18–4

NIOSH REL: Minimize workplace exposure concentrations; NIOSH considers tetrachloroethylene to be a potential occupational carcinogen as defined by the OSHA carcinogen policy [29 CFR 1990].

Current OSHA PEL: 100 ppm TWA, 200 ppm CEILING,

300 ppm 5-minute MAXIMUM PEAK IN ANY 3 HOURS

1989 OSHA PEL: 25 ppm (170 mg/m3) TWA

1993-1994 ACGIH TLV: 25 ppm (170 mg/m3) TWA, 100 ppm (685 mg/m3) STEL, A3

Description of substance: Colorless liquid with a mild, chloroform-like odor.

LEL:. . Noncombustible Liquid

Original (SCP) IDLH: 500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Negherbon [1959] that a 95-minute exposure to 1,000 ppm produces slight drunkenness, but no narcosis [Rowe et al. 1952]. Negherbon [1959] also reported that a 20- to 30-minute exposure to 206 to 235 ppm causes dizziness in humans (along with eye irritation, sinus congestion, nasal discharge, and sleepiness) [Rowe et al. 1952]. An IDLH of 500 ppm is used to prevent disorientation during escape.

Short-term exposure guidelines: None developed


Lethal concentration data:






TimeAdjusted 0.5-hr

LC (CF*)

Derived value
RatCarpenter et al. 1949 4,000-----4 hr11,320 ppm (2.83)1,132 ppm
MouseFriberg et al. 1953 5,200-----4 hr14,716 ppm (2.83)1,472 ppm
RatPozzani et al. 1959 4,964-----8 hr19,856 ppm (4.0) 1,986 ppm

*Note: Conversion factor (CF) was determined with "n" = 2.0 [ten Berge et al. 1986].

Human data: It has been reported that 2,000 ppm caused slight narcosis in 5 minutes; 930-1185 ppm caused irritation of the eyes and throat, and marked dizziness after 2 minutes; 1,000 ppm caused slight drunkenness, but no narcosis after 95 minutes; 513-690 ppm caused eye, throat, and nose irritation, dizziness, loss of inhibition, and some incoordination after 10 minutes; 500 ppm for 2 hours caused slight discomfort; 206-356 ppm for 2 hours caused headache, burning of the eyes, sinus congestion, impaired coordination, and nausea; 206-235 ppm for 20-30 minutes caused eye irritation, sinus congestion, dizziness, and sleepiness; and 106 ppm caused only slight eye irritation [Negherbon 1959; Rowe et al. 1952].


Revised IDLH: 150 ppm

Basis for revised IDLH: The revised IDLH for tetrachloroethylene is 150 ppm based on acute inhalation toxicity data in humans [Negherbon 1959; Rowe et al. 1952] [Note: NIOSH recommends as part of its carcinogen policy that the "most protective" respirators be worn for tetrachloroethylene at any detectable concentration.]


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 31:343-346.

2. Friberg L, Kylin B, Nystrom A [1953]. Toxicities of trichloroethylene and tetrachloroethylene and Fujiwara's pyridine-alkali reaction. Acta Pharmacol Toxicol 9:303-312.

3. Negherbon WO [1959]. Handbook of toxicology. Vol. III. Insecticides, a compendium. Wright-Patterson Air Force Base, OH: U.S. Air Force, Air Research and Development Command, Wright Air Development Center, Aero Medical Laboratory, WADC Technical Report 55-16, p. 737.

4. Pozzani UC, Weil CS, Carpenter CP [1959]. The toxicological basis of threshold limit values: 5. The experimental inhalation of vapor mixtures by rats, with notes upon the relationship between single dose inhalation and single dose oral data. Am Ind Hyg Assoc J 20:364-369.

5. Rowe VK, McCollister DD, Spencer HC, Adams EM, Irish DD [1952]. Vapor toxicity of tetrachloroethylene for laboratory animals and human subjects. AMA Arch Ind Hyg Occup Med 5:566-579.

6. ten Berge WF, Zwart A, Appelman LM [1986]. Concentration-time mortality response relationship of irritant and systematically acting vapours and gases. J Haz Mat 13:301-309.

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