An official website of the United States government
Camphor (synthetic)
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 76–22–2
NIOSH REL: 2 mg/m3 TWA
Current OSHA PEL: 2 mg/m3 TWA
1989 OSHA PEL: Same as current PEL
1993-1994 ACGIH TLV: 12 mg/m3 (2 ppm) TWA, 19 mg/m3 (3 ppm) STEL
Description of Substance: Colorless or white crystals with a penetrating, aromatic odor.
LEL: . . 0.6% (10% LEL, 3,600 mg/m3)
Original (SCP) IDLH: 200 mg/m3
Basis for original (SCP) IDLH: No data on acute inhalation toxicity are available on which to base an IDLH for camphor. For this draft technical standard, therefore, the chosen IDLH is based on a report by Gronka et al. [1969] concerning the camphor processing and packaging area of a plant. Concentrations of camphor ranging from 3 to 194 mg/m3 produced nose and sinus irritation among workers in this plant [Gronka et al. 1969].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA
Lethal concentration data:
| Species | Reference | LC50 | LCLo | Time | Adjusted 0.5-hrLC (CF) | DerivedValue |
|---|---|---|---|---|---|---|
| Mouse | Nikolaeva 1957 | —– | 400 mg/m3 | 3 hr | 720 mg/m3 (1.8) | 72 mg/m3 |
Lethal dose data:
| Species | Reference | Route | LD50(mg/kg) | LDLo(mg/kg) | Adjusted LD | Derived value |
|---|---|---|---|---|---|---|
| DogMouse
Rabbit |
Flury and Zernik 1935Horikawa and Okada 1975
Smith and Margolis 1954 |
oraloral
oral |
—–1,310
—– |
800—–
2,000 |
5,600 mg/m39,170 mg/m3
14,000 mg/m3 |
560 mg/m3917 mg/m3
1,400 mg/m3 |
Human data: It has been reported that concentrations during camphor processing and packaging ranged from 33 to 194 mg/m3; workers had no complaints other than slight eye irritation and afternoon drowsiness [Gronka et al. 1969].
| Revised IDLH: 200 mg/m3 [Unchanged]Basis for revised IDLH: Based on chronic inhalation toxicity data in workers [Gronka et al. 1969], the original IDLH for synthetic camphor (200 mg/m3) is not being revised at this time. |
REFERENCES:
1. Flury F, Zernik F [1935]. Zusammenstellung der toxischen und letalen dosen für die gebräuchlichsten gifte und versuchstiere. Abder Hand Biol Arbeitsmethod 4:1289-1422 (in German).
2. Gronka PA, Bobkoski RL, Tomchick GJ, Rakow AB [1969]. Camphor exposures in a packaging plant. Am Ind Hyg Assoc J 30:276-279.
3. Horikawa E, Okada T [1975]. Experimental study on acute toxicity of phenol camphor. Shika Gakuho (Journal of Dentistry) 75:934-939 (in Japanese).
4. Nikolaeva [1957]. Toxicological evaluation of camphor vapors. Gig Sanit 22(11):83-86 (in Russian).
5. Smith AG, Margolis G [1954]. Camphor poisoning: anatomical and pharmacologic study; report of a fatal case; experimental investigation of protective action of barbiturate. Am J Pathol 30(5):857-868.