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Dichloromonofluoromethane
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 75–43–4
NIOSH REL: 10 ppm (40 mg/m3) TWA
Current OSHA PEL: 1,000 ppm (4,200 mg/m3) TWA
1989 OSHA PEL: 10 ppm (40 mg/m3) TWA
1993-1994 ACGIH TLV: 10 ppm (42 mg/m3) TWA
Description of Substance: Colorless gas with a slight, ether-like odor.
LEL:. . Nonflammable Gas
Original (SCP) IDLH: 50,000 ppm
Basis for original (SCP) IDLH: ACGIH [1971] reported that 52,000 ppm produced incoordination, irregular breathing, and tremors in guinea pigs [Underwriters’ Laboratory 1935]. Scheel (member of the Standards Completion Program Respirator Committee), in evaluating the work of Aviado and Belej [1974], indicated cardiac toxicity at 100,000 ppm. Based on the above data, an IDLH of 50,000 ppm has been chosen.
Existing short-term exposure guidelines: National Research Council [NRC 1984] Emergency Exposure Guidance Levels (EEGLs):
1-hour EEGL: 100 ppm
24-hour EEGL: 3 ppm
ACUTE TOXICITY DATA
Lethal concentration data:
| Species | Reference | LC50 | LCLo | Time | Adjusted 0.5-hrLC (CF) | Derivedvalue |
|---|---|---|---|---|---|---|
| MouseRatG. pig
Mouse |
Kozbakova 1976Tappan and Waritz 1964von Weigand 1971
von Weigand 1971 |
>800,000 mg/m349,900 ppm—–
—– |
—–—–100,000 ppm
100,000 ppm |
2 hr4 hr<1 hr
<1 hr |
>373,832 ppm (2.0)99,800 ppm (2.0)<125,000 ppm (1.25)
<125,000 ppm (1.25) |
>37,383 ppm9,980 ppm<12,500 ppm
<12,500 ppm |
Other animal data: In 5-minute cardiac sensitization screening tests, 2 of 12 unanesthetized dogs exposed to 10,000 ppm of dichloromonofluoromethane plus intravenous epinephrine showed evidence of serious arrhythmia; no response was noted at 5,000 ppm [Mullin 1975].
Human data: None relevant for use in determining the revised IDLH.
| Revised IDLH: 5,000 ppmBasis for revised IDLH: The revised IDLH for dichloromonofluoromethane is 5,000 ppm based on acute inhalation toxicity data in animals [Mullin 1975; Tappan and Waritz 1964; von Weigand 1971]. This may be a conservative value due to the lack of relevant acute toxicity data for workers. |
REFERENCES:
1. ACGIH [1971]. Dichloromonofluoromethane. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 81-82.
2. Aviado DM, Belej MA [1974]. Toxicity of aerosol propellants on the respiratory and circulatory systems. I. Cardiac arrythmia in the mouse. Toxicology 2:31-42.
3. Kozbakova AE [1976]. Comparative toxicity of chlorinated and fluorinated methane and ethane derivatives. Gig Tr Prof Zabol 20(11):38-41 (in Russian).
4. Mullin LS [1975]. Unpublished data. Newark, DE: Haskell Laboratory, E.I. DuPont de Nemours and Company, November 1975. [From ACGIH [1991]. Dichlorofluoromethane. In: Documentation of the threshold limit values and biological exposure indices. 6th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 434-435.]
5. 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. 41-45.
6. Tappan CH, Waritz RS [1964]. Unpublished data: acute inhalation toxicity of Freon-21® (fluorodichloromethane). Report No. 128-64. Newark, DE: E.I. DuPont de Nemours and Company, Haskell Laboratory for Toxicology and Industrial Medicine, November 1964.
7. Underwriters’ Laboratory [1935]. The comparative life, fire, and explosion hazards of dichloromonofluoromethane (F21). Miscellaneous Hazard Report No. 2630. [From ACGIH [1971]. Dichloromonofluoromethane. In: Documentation of the threshold limit values for substances in workroom air. 3rd ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, pp. 81-82.]
8. von Weigand W [1971]. Investigations on the inhalation toxicity of fluorine derivatives of methane, ethane, and cyclobutane. Zentralbl Arbeitsmed Arbeitsschutz 21:149-156 (in German).