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Zirconium compounds (as Zr)
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 7440–67–7 (Metal)
NIOSH REL: 5 mg/m3 TWA, 10 mg/m3 STEL
Current OSHA PEL: 5 mg/m3 TWA
1989 OSHA PEL: 5 mg/m3 TWA, 10 mg/m3 STEL
1993-1994 ACGIH TLV: 5 mg/m3 TWA, 10 mg/m3 STEL
Description of substance: Varies
Original (SCP) IDLH: 500 mg Zr/m3
Basis for original (SCP) IDLH: The available toxicological data indicate that zirconium compounds possess a low order of toxicity. The chosen IDLH has been based on the citation by NIOSH [1976] that a 30-minute exposure to 500 mg/m3 of zirconium nitrate is the lowest concentration of this substance which has been shown to be lethal to rats [Mogilevskaya 1967].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
| Species | Reference | LC50 | LCLo | Time | Adjusted 0.5-hrLC (CF) | Derived value |
|---|---|---|---|---|---|---|
| Zr(NO3)2 Rat | Mogilevskaya 1967 | —– | 500 mg/m3 | 30 min | 212 mg Zr/m3 (1.0) | 21 mg Zr/m3 |
Lethal dose data:
| Species | Reference | Route | LD50(mg/kg) | LDLo(mg/kg) | Adjusted LD | Derived value |
| ZrF6×2K Mouse | Shalganova 1967 | oral | 98 | —– | 221 mg Zr/m3 | 22 mg Zr/m3 |
| Zr(SO4)2 Rat | Cochran et al. 1950 | oral | 3,500 | —– | 7,886 mg Zr/m3 | 789 mg Zr/m3 |
| ZrOCl2 Mouse | Delongeas et al. 1983 | oral | 1,227 | —– | 4,398 mg Zr/m3 | 440 mg Zr/m3 |
| ZrOCl2 Rat | Klimmer & Doll 1964 | oral | 2,950 | —– | 10,573 mg Zr/m3 | 1,057 mg Zr/m3 |
| ZrCl4 Rat | ACGIH 1986 | oral | 1,688 | —– | 4,643 mg Zr/m3 | 464 mg Zr/m3 |
| ZrCl4 Mouse | ACGIH 1986 | oral | 655 | —– | 1,801 mg Zr/m3 | 180 mg Zr/m3 |
| ZrF4 Rat | ACGIH 1986 | oral | 98 | —– | 374 mg Zr/m3 | 37 mg Zr/m3 |
Human data: None relevant for use in determining the revised IDLH.
| Revised IDLH: 25 mg Zr/m3Basis for revised IDLH: The revised IDLH for zirconium compounds is 25 mg Zr/m3 based on acute toxicity data in animals [ACGIH 1986; Mogilevskaya 1967; Shalganova 1967]. This may be a conservative value due to the lack of relevant acute inhalation toxicity data for workers. |
REFERENCES:
1. ACGIH [1986]. Zirconium. In: Documentation of the threshold limit values and biological exposure indices. 5th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, p. 647.
2. Cochran KW, Doull J, Mazur M, DuBois KP [1950]. Acute toxicity of zirconium, columbium, strontium, lanthanum, cesium, tantalum and yttrium. AMA Arch Ind Hyg Occup Med 1:637-650.
3. Delongeas JL, Burnel D, Netter P, Grignon M, Mur JM, Royer RJ, Grignon G [1983]. Toxicité et pharmacocinétique de l’oxychlorure de zirconium chez la souris et chez le rat. J Pharmacol 14(4):437-447 (in French).
4. Klimmer OR, Doll W [1964]. Zur frage der toxizität und speicherung löslicher zirkoniumverbindungen bei kurz- und langdauernder verfütterung an warmblüter. Arzneimittel-Forschung (Drug Research) 14:1286-1290 (in German).
5. Mogilevskaya OY [1967]. Zirconium. In: Toxicology of the rare metals, ZI Izrael’son, ed. Translated from Russian by Y. Halperin, edited by E. Lieber. Washington, DC: U.S. Atomic Energy Commission and the National Science Foundation, pp. 44-52.
6. NIOSH [1976]. ZH87500. Zirconium nitrate. 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. 1230.
7. Shalganova IV [1967]. Hygienic features of the production of rare-metal fluorides. Gig Sanit 32(10-12):343-347 (translated).