Zinc chloride fume

CAS number: 7646–85–7

NIOSH REL: 1 mg/m³ TWA, 2 mg/m³ STEL

Current OSHA PEL: 1 mg/m³ TWA

1989 OSHA PEL: 1 mg/m³ TWA, 2 mg/m³ STEL

1993-1994 ACGIH TLV: 1 mg/m³ TWA, 2 mg/m³ STEL

Description of substance: White particulate dispersed in air.

LEL: . . Noncombustible Solid

Original (SCP) IDLH*: 4,800 mg/m³ [*Note: "Effective" IDLH = 2,000 mg/m³ -- see discussion below.]

Basis for original (SCP) IDLH: The chosen IDLH is based on the 30-minute human TC_LO of 4,800 mg/m³ zinc chloride [Ferry 1974 cited by NIOSH 1976]; and the toxic effects involved the respiratory system. No other data on acute inhalation toxicity are available on which to base the IDLH for zinc chloride fume. Because of the assigned protection factor afforded by each device, however, 2,000 ´ the OSHA PEL (i.e., 2,000 mg/m³) is the concentration above which only the "most protective" respirators are permitted.

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species	Reference	LC50	LCLo	Time	Adjusted 0.5-hr LC (CF)	Derived value
Rat	Karlsson et al. 1986	LC67: 1,960 mg/m3	-----	10 min	1,352 mg/m3	135 mg/m3
Rat	Marrs et al. 1983	1,260 mg/m3	-----	30 min	1,260 mg/m3	126 mg/m3
Rabbit	Marrs et al. 1983	LC70: 1,260 mg/m3	-----	30 min	1,260 mg/m3	126 mg/m3
Mouse	Marrs et al. 1983	11,80 mg-min/m3	-----	-----	393 mg/m3	39 mg/m3

Lethal dose data:

Species	Reference	Route	LD50 (mg/kg)	LDLo (mg/kg)	Adjusted LD	Derived value
Rat	Calvery 1942	oral	350	-----	2,450 mg/m3	245 mg/m3
Mouse	Calvery 1942	oral	350	-----	2,450 mg/m3	245 mg/m3
G. pig	Calvery 1942	oral	200	-----	1,400 mg/m3	140 mg/m3
Rat	Domingo et al. 1988	oral	1,100	-----	7,700 mg/m3	770 mg/m3
Mouse	Domingo et al. 1988	oral	1,250	-----	8,750 mg/m3	875 mg/m3

Other animal data: It has been reported that 90 mg/m³ is the no observed adverse effect level (NOEL) for rat intratracheal fibrosis [Richards et al. 1989].

Human data: A 30-minute exposure to 4.8 mg/m³ has been reported to produce respiratory distress [Ferry 1974]. Exposure to 80 mg/m³ has caused nausea and coughing and 120 mg/m³ for 2 minutes has caused nose and upper respiratory system irritation [Cullumbine 1957].

Revised IDLH: 50 mg/m3 Basis for revised IDLH: The revised IDLH for zinc chloride fume is 50 mg/m3 based on acute toxicity data in humans [Cullumbine 1957] and animals [Richards et al. 1989].

REFERENCES:

1. Calvery HO [1942]. Trace elements in foods. Food Res 7:313-331.

2. Cullumbine H [1957]. The toxicity of screening smokes. J Royal Army Med Corps 103:119-122.

3. Domingo JL, Llobet JM, Paternain JL, Corbella J [1988]. Acute zinc intoxication. Vet Hum Toxicol 30(3):224-228.

4. Ferry JJ [1974]. Personal communication with area manager of industrial & environmental hygiene. General Electric Company, 1 River Road, Schenectady, NY 12345.

5. Karlsson N, Cassel G, Fangmark I, Bergman F [1986]. A comparative study of the acute inhalation toxicity of smoke from TiO₂-hexachloroethane and Zn-hexachloroethane pyrotechnic mixtures. Arch Toxicol 59(3):160-166.

6. Marrs TC, Clifford WE, Colgrave HF [1983]. Pathological changes produced by exposure of rabbits and rats to smokes of hexachloroethane and zinc oxide. Toxicology Lett 19:247-252.

7. NIOSH [1976]. ZH14000. Zinc chloride. In: Registry of toxic effects of chemical substances, 1976 ed. Cincinnati, OH: U.S. Department of Health, Education, and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 76-191, p. 1228.

8. Richards RJ, Atkins J, Marrs TC, Brown RFR, Masek L [1989]. The biological and pathological changes produced by the intratracheal instillation of certain compounds of zinc-hexachloroethane smoke. Toxicology 54(1):79-88.