Phosgene

CAS number: 75–44–5

NIOSH REL: 0.1 ppm (0.4 mg/m³) TWA,

0.2 ppm (0.8 mg/m³) 15-minute CEILING

Current OSHA PEL: 0.1 ppm (0.4 mg/m³) TWA

1989 OSHA PEL: Same as current PEL

1993-1994 ACGIH TLV: 0.1 ppm (0.40 mg/m³) TWA

Description of substance: Colorless gas with a suffocating odor like musty hay.

LEL: . . Nonflammable Gas

Original (SCP) IDLH: 2 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Jacobs [1967] that 1 part in 200,000 (5 ppm) is probably lethal for exposures of 30 minutes. Gross et al. [1965] indicated that concentrations as low as 0.5 ppm for 2 hours caused definite pathological changes in the lungs of rats sacrificed 96 hours post exposure; the investigators believed some abnormalities were present 3 months after rats had been exposed at 2 ppm for 80 minutes. An IDLH of 2 ppm is used for phosgene to prevent irreversible adverse health effects.

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

1-hour EEGL: 0.2 ppm

24-hour EEGL: 0.02 ppm

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50 (ppm)	LCLo (ppm)	Time	Adjusted 0.5-hr LC (CF)	Derived value
Human Human Human Mammal Human Cat Rat Mouse Rabbit G. pig Dog Monkey Human Mammal	Diller 1978 Diller 1978 Diller 1978 Flury 1928 Izmerov et al. 1982 Izmerov et al. 1982 NDRC 1946 NDRC 1946 NDRC 1946 NDRC 1946 NDRC 1946 NDRC 1946 Tab Biol Per 1933 Tab Biol Per 1933	500 ----- ----- ----- ----- ----- 340 438 243 316 1,022 145 ----- -----	----- 3 30 50 88 46 ----- ----- ----- ----- ----- ----- 50 2.7	1 min 2.83 hr 17 min 5 min 30 min 15 min 30 min 30 min 30 min 30 min 20 min 1 min 5 min 30 min	160 ppm (0.32) 5.3 ppm (1.78) 25 ppm (0.82) 28 ppm (0.55) 88 ppm (1.0) 37 ppm (0.79) 340 ppm (1.0) 438 ppm (1.0) 243 ppm (1.0) 316 ppm (1.0) 981 ppm (0.96) 46 ppm (0.32) 28 ppm (0.55) 2.7 ppm (1.0)	16 ppm 0.5 ppm 2.5 ppm 2.8 ppm 8.8 ppm 3.7 ppm 34 ppm 44 ppm 24 ppm 32 ppm 98 ppm 4.6 ppm 2.8 ppm 0.3 ppm

Other animal data: It has been reported that concentrations as low as 0.5 ppm for 2 hours caused definite pathological changes in the lungs of rats sacrificed 96 hours post exposure; the investigators believed some abnormalities were present 3 months after the rats had been exposed at 2 ppm for 80 minutes [Gross et al. 1965].

Other human data: It has been calculated that based on acute toxicity data in humans, the lethal dose for a 30-minute exposure would be about 17 ppm [Diller 1978]. It has been stated that 25 ppm for 30 to 60 minutes is dangerous and brief exposure to 50 ppm may be rapidly fatal [Henderson and Haggard 1943]. It has also been stated that 5 ppm is probably lethal for a 30-minute exposure [Jacobs 1967].

Revised IDLH: 2 ppm [Unchanged] Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Diller 1978; Jacobs 1967], the original IDLH for phosgene (2 ppm) is not being revised at this time.

REFERENCES:

1. Diller WF [1978]. Medical phosgene problems and their possible solution. J Occup Med 20:189-193.

2. Flury F [1928]. Moderne gewerbliche vergiftungen in pharmakologisch-toxikologischer hinsicht (Pharmacological-toxicological aspects of intoxicants in modern industry). Arch Exp Pathol Pharmakol 138:65-82 (translated).

3. Gross P, Rinehart WE, Hatch T [1965]. Chronic pneumonitis caused by phosgene. Arch Environ Health 10:768-775.

4. Henderson Y, Haggard HW [1943]. Noxious gases. 2nd ed. New York, NY: Reinhold Publishing Corporation, pp. 137-138.

5. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 99.

6. Jacobs MB [1967]. The analytical toxicology of industrial inorganic poisons. New York, NY: Interscience Publishers, pp. 648-649.

7. NDRC [1946]. Summary technical report of division 9, NDRC. Vol 1. Chemical warfare agents and related chemical problems. Parts I-II. Washington, DC: National Defence Research Committee, pp. 1-385.

8. 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. 69-86.

9. Tab Biol Per [1933]; 3:231 (in German).