May 1994

Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs)

Camphor (synthetic)

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	LC_Lo	Time	Adjusted 0.5-hr LC (CF)	Derived Value
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)

LD_Lo

(mg/kg)

Adjusted LD

Derived value

Dog

Mouse

Rabbit

Flury and Zernik 1935

Horikawa and Okada 1975

Smith and Margolis 1954

oral

-----

1,310

-----

800

-----

2,000

5,600 mg/m³

9,170 mg/m³

14,000 mg/m³

560 mg/m³

917 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.