NIOSH logo and tagline


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

CAS number: 76-13-1

NIOSH REL: 1,000 ppm (7,600 mg/m3) TWA,

1,250 ppm (9,500 mg/m3) STEL

Current OSHA PEL: 1,000 ppm (7,600 mg/m3) TWA

1989 OSHA PEL: 1,000 ppm (7,600 mg/m3) TWA,

1,250 ppm (9,500 mg/m3) STEL

1993-1994 ACGIH TLV: 1,000 ppm (7,670 mg/m3) TWA,

1,250 ppm (9,590 mg/m3) STEL

Description of substance: Colorless to water-white liquid with an odor like carbon tetrachloride at high concentrations.

LEL: . . Unknown

Original (SCP) IDLH: 4,500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by AIHA [1968] and ACGIH [1971] that a 2.75-hour exposure to 4,500 ppm significantly impaired the psychomotor performance of human volunteers [Stopps and McLaughlin 1967].

Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):

1-hour EEGL: 1,500 ppm

24-hour EEGL: 500 ppm


Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derived value
MouseRat Burns et al. 1961Clayton 1962 ———- 250,00087,000 1.5 min6 hr 92,500 ppm (0.37)200,100 ppm (2.3) 9,250 ppm20,010 ppm

Other animal data: Dogs appear to tolerate 1,000 ppm, regardless of duration of exposure but exhibit cardiac abnormalities when exposed to 2,000 ppm for 6 hours and immediately challenged with epinephrine [Aviado 1975]. Also, dogs exposed for 5 minutes to 2,500 ppm or higher and then challenged with epinephrine developed cardiac sensitization [Reinhardt et al. 1973]. Others have reported that dogs exposed while running on a treadmill (to increase their own epinephrine concentration) were not sensitized at concentrations up to 20,000 ppm [Trochimowicz et al. 1974].

Human data: Human volunteers exposed to 2,500 ppm had subjective symptoms of diminished concentration, somnolence, and head heaviness within 30 minutes of initiation of exposure and slight but definite further significant decrements at exposures for 2.75 hours at 4,500 ppm [Stopps and McLaughlin 1967]. No adverse changes were noted in volunteers exposed to 500 or 1,000 ppm for 6 hours per day, 5 days per week for 2 weeks [Reinhardt et al. 1971].


1. ACGIH [1971]. 1,1,2-Trichloro-1,2,2-trifluoroethane. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 267-268.

2. AIHA [1968]. 1,1,2-Trichloro-1,2,2-trifluoroethane. In: Hygienic guide series. Am Ind Hyg Assoc J 29:521-525.

3. Aviado DM [1975]. Toxicology of aerosol propellants in the respiratory and circulatory systems. X. Proposed classification. Toxicology 3:321-332.

4. Burns THS, Hall JM, Bracken A, Gouldstone G, Newland DS [1961]. An investigation of new fluorine compounds in anaesthesia. Anaesthesia 16:3-18.

5. Clayton JW [1962]. The toxicity of fluorocarbons with special reference to chemical constitution. J Occup Med 4:262-273.

6. NRC [1984]. Emergency and continuous exposure limits for selected airborne contaminants. Vol. 2. Washington, DC: National Academy Press, Committee on Toxicology, Board on Toxicology and Environmental Health Hazards, Commission on Life Sciences, National Research Council, pp. 46-50.

7. Reinhardt CF, McLaughlin M, Maxfield ME, Mullin LS, Smith PE Jr [1971]. Human exposure to fluorocarbon 113 (1,1,2-trichloro-1,2,2-trifluoroethane). Am Ind Hyg Assoc J 32:143-152.

8. Reinhardt CF, Mullin LS, Maxfield ME [1973]. Epinephrine-induced cardiac arrhythmia potential of some common industrial solvents. J Occup Med 15(12):953-955.

9. Stopps GJ, McLaughlin M [1967]. Psychophysiological testing of human subjects exposed to solvent vapors. Am Ind Hyg Assoc J 28:43-50.

10. Trochimowicz HJ, Azar A, Terrill JB, Mullin LS [1974]. Blood levels of fluorocarbon related to cardiac sensitization: part II. Am Ind Hyg Assoc J 35:632-639.