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o-Methylcyclohexanone

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

CAS number: 583–60–8

NIOSH REL: 50 ppm (230 mg/m3) TWA, 75 ppm 345 mg/m3) STEL [skin]

Current OSHA PEL: 100 ppm (460 mg/m3) TWA [skin]

1989 OSHA PEL: 50 ppm (230 mg/m3) TWA, 75 ppm (345 mg/m3) STEL [skin]

1993-1994 ACGIH TLV: 50 ppm (229 mg/m3) TWA, 75 ppm (344 mg/m3) STEL [skin]

Description of substance: Colorless liquid with a weak, peppermint-like odor.

LEL:. . . Unknown

Original (SCP) IDLH: 2,500 ppm

Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that rabbits and cats exhibited sleepiness, respiratory irregularities, and poor coordination after a 1-hour exposure to 2,500 ppm; a 30-minute exposure to 3,500 ppm caused prostration in mice, guinea pigs, and rats [Gross as cited by Lehmann and Flury 1943].

Short-term exposure guidelines: None developed

ACUTE TOXICITY DATA:

Lethal concentration data:

Species Reference LC50(ppm) LCLo(ppm) Time Adjusted 0.5-hrLC (CF) Derived value
Rat Smyth et al. 1969 2,800 —– 4 hr 5,600 ppm (2.0) 560 ppm

Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived value
Rat Smyth et al. 1969 oral 2,140 —– 3,215 ppm 322 ppm
Rabbit Treon et al. 1943 oral —– 1,000-1,250 1,502-1,878 ppm 150-188 ppm

Other animal data: Mice, guinea pigs, and rats exposed at 3,500 ppm for 30 minutes suffered irritation of the mucous membranes and exhibited signs of central nervous system depression [Clayton and Clayton 1981]. Rabbits and cats exhibited sleepiness, respiratory irregularities, and poor coordination after a 1-hour exposure to 2,500 ppm [Clayton and Clayton 1981].

Human data: None relevant for use in determining the revised IDLH.

REFERENCES:

1. Clayton GD, Clayton FE, eds. [1981]. Patty’s industrial hygiene and toxicology. 3rd rev. ed. Vol. 2C. Toxicology. New York, NY: John Wiley & Sons, Inc., pp. 4722-4723, 4782-4784.

2. Gross E [?]. Unpublished. [From Lehmann KB, Flury F, eds. [1943]. Toxicology and hygiene of industrial solvents. Translated by E. King and H.F. Smyth, Jr. Baltimore, MD: Williams & Wilkins Company, p. 247.]

3. Lehmann KB, Flury F, eds. [1943]. Toxicology and hygiene of industrial solvents. Translated by E. King and H.F. Smyth, Jr. Baltimore, MD: Williams & Wilkins Company, p. 247.

4. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1770.

5. Smyth HF Jr, Carpenter CP, Weil CS, Pozzani UC, Striegel JA, Nycum JS [1969]. Range-finding toxicity data: list VII. Am Ind Hyg Assoc J 30(5):470-476.

6. Treon JF, Crutchfield WE Jr, Kitzmiller KV [1943]. The physiological response of rabbits to cyclohexane, methylcyclohexane, and certain derivatives of these compounds. I. Oral administration and cutaneous application. J Ind Hyg Toxicol 25(6):199-214.