Copper (dusts and mists, as Cu)

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

CAS number: 7440–50–8 (Metal)

NIOSH REL: 1 mg/m3 TWA

1989 OSHA PEL: Same as current PEL

Current OSHA PEL: 1 mg/m3 TWA

1993-1994 ACGIH TLV: 1 mg/m3 TWA

Description of Substance: Varies

Original (SCP) IDLH*: No Evidence [*Note: “Effective” IDLH = 2,000 mg Cu/m3 — see discussion below.]

Basis for original (SCP) IDLH: There is no evidence that an acute exposure to a high concentration of copper dusts and mists could impede escape within 30 minutes. Browning [1969] noted that there is little evidence that copper presents a serious industrial hazard, either from acute or chronic poisoning. For this draft technical standard, therefore, respirators have been selected on the basis of the assigned protection factor afforded by each device up to 2,000 × the OSHA PEL of 1 mg Cu/m3 (i.e., 2,000 mg Cu/m3); only the “most protective” respirators are permitted for use in concentrations exceeding 2,000 mg Cu/m3.

Short-term exposure guidelines: None developed


Lethal concentration data:

Species Reference LC50 LCLo Time Adjusted 0.5-hrLC (CF) Derivedvalue
Worthing 1991 >2,000 mg/m3 —– ? ? ?


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
Sine 1991 oral 1,000 —– 4,559 mg Cu/m3 456 mg Cu/m3
Coulston and Korte 1975 oral 140 —– 629 mg Cu/m3 63 mg Cu/m3
Marhold 1977 oral 595 —– 1,457 mg Cu/m3 146 mg Cu/m3
Siegle and Sisler 1977 oral 300 —– 836 mg Cu/m3 84 mg Cu/m3


Human data: It has been stated that there is little evidence that copper presents a serious industrial hazard, either from acute or chronic poisoning [Browning 1969]. Inhalation of copper salts can result in irritation of the nasal mucous membranes [Clayton and Clayton 1981]. A lethal oral dose of 857 mg of CuSO4/kg (equivalent to 341 mg Cu/kg) has been reported [Csiky 1958]. [Note: An oral dose of 341 mg Cu/kg is equivalent to a 70-kg worker being exposed to 227 mg Cu/m3 for 30 minutes, assuming a breathing rate of 50 liters per minute and 100% absorption.]

Revised IDLH: 100 mg Cu/m3Basis for revised IDLH: The revised IDLH for copper dusts and mists is 100 mg Cu/m3 based on acute oral toxicity data in humans [Csiky 1958] and animals [Coulston and Korte 1975; Marhold 1977; Siegel and Sisler 1977]. This may be a conservative value due to the lack of relevant acute inhalation toxicity data in workers.



1. Browning E [1969]. Toxicity of industrial metals. 2nd ed. New York, NY: Appleton-Century-Crofts, p. 148.

2. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2A. Toxicology. New York, NY: John Wiley & Sons, Inc., pp. 1620-1630.

3. Coulston F, Korte F, eds. [1975]. Heavy metal toxicity, safety and hormology. In: Environmental Quality & Safety, Supplement 1. New York, NY: Georg Thieme Publishers, pp. 1-120.

4. Csiky P [1958]. Uber die akuten kupfersulfat-vergiftungen. Arch Toxikol 17:20-26 (in German).

5. Marhold JV [1977]. Personal communication. VUOS, 539-18, Pardubice, Czechoslovakia, March 29, 1977.

6. Siegel MR, Sisler HD [1977]. Antifungal compounds. Vol. 1. New York, NY: Marcel Dekker, p. 507.

7. Sine C, ed. [1991]. Copper hydroxide. In: Farm chemicals handbook ’91, p. C89.

8. Worthing CR, ed. [1991]. Copper hydroxide. In: The pesticide manual. A world compendium. 9th ed. Farnham, Surrey, United Kingdom: The British Crop Protection Council, p. 184.

Page last reviewed: December 4, 2014