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Mesityl oxide
May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)
CAS number: 141–79–7
NIOSH REL: 10 ppm (40 mg/m3) TWA
Current OSHA PEL: 25 ppm (100 mg/m3) TWA
1989 OSHA PEL: 15 ppm (60 mg/m3) TWA, 25 ppm (100 mg/m3) STEL
1993-1994 ACGIH TLV: 15 ppm (60 mg/m3) TWA, 25 ppm (100 mg/m3) STEL
Description of substance: Oily, colorless to light-yellow liquid with a peppermint- or honey-like odor.
LEL: . 1.4% (10% LEL, 1,400 ppm)
Original (SCP) IDLH: 5,000 ppm
Basis for original (SCP) IDLH: The chosen IDLH is based on the statement by Patty [1963] that 5,000 ppm might be dangerous to life in 30 to 60 minutes [Smyth et al. 1942].
Short-term exposure guidelines: None developed
ACUTE TOXICITY DATA:
Lethal concentration data:
| Species | Reference | LC50 | LCLo | Time | Adjusted 0.5-hrLC (CF) | Derived value |
|---|---|---|---|---|---|---|
| RatRat
Mouse G. pig |
Carpenter et al. 1949Izmerov et al. 1982
Izmerov et al. 1982 Specht et al. 1940 |
1,000 mg/m39,000 mg/m3
10,000 mg/m3 2,000 mg/m3 |
———-
—– —– |
4 hr4 hr
2 hr 7 hr |
2,000 ppm (2.0)18,000 ppm (2.0)
16,000 ppm (1.6) 4,800 ppm (2.4) |
200 ppm1,800 ppm
1,600 ppm 480 ppm |
Lethal dose data:
| Species | Reference | Route | LD50(mg/kg) | LDLo(mg/kg) | Adjusted LD | Derived value |
|---|---|---|---|---|---|---|
| RatRabbit
Mouse |
Hann &Jansen 1974Hann & Jansen 1974
Izmerov et al. 1982 |
oraloral
oral |
1,1201,000
710 |
———-
—– |
1,922 ppm1,716 ppm
1,218 ppm |
192 ppm172 ppm
122 ppm |
Human data: The probable response to 100 ppm was predicted to be eye and mucous membrane irritation, difficulty breathing, headache, and vertigo [Shell 1957]. It has been stated that 5,000 ppm might be dangerous to life in 30 to 60 minutes [Smyth et al. 1942].
| Revised IDLH: 1,400 ppm [LEL]Basis for revised IDLH: Based on health considerations and acute inhalation toxicity data in humans [Smyth et al. 1942], a value of about 4,000 ppm would have been appropriate for mesityl oxide. However, the revised IDLH for mesityl oxide is 1,400 ppm based strictly on safety considerations (i.e., being 10% of the lower explosive limit of 1.4%). |
REFERENCES:
1. Carpenter CP, Smyth HF Jr, Pozzani UC [1949]. The assay of acute vapor toxicity, and the grading and interpretation of results on 96 chemical compounds. J Ind Hyg Toxicol 31(6):343-346.
2. Hann W, Jansen PA [1974]. Water quality characteristics of hazardous materials. Vols. 1-4. College Station, TX: Texas A & M University, Civil Engineering Department, Environmental Engineering Division.
3. Izmerov NF, Sanotsky IV, Sidorov KK [1982]. Toxicometric parameters of industrial toxic chemicals under single exposure. Moscow, Russia: Centre of International Projects, GKNT, p. 80.
4. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1758.
5. Shell [1957]. Mesityl oxide: safety data sheet SC:57-105. New York, NY: Shell Chemical Corporation, pp. 1-3.
6. Smyth HF Jr, Seaton J, Fischer L [1942]. Response of guinea pigs and rats to repeated inhalation of vapors of mesityl oxide and isophorone. J Ind Hyg Toxicol 24(3):46-50.
7. Specht H, Miller JW, Valaer PJ, Sayers RR [1940]. Acute response of guinea pigs to the inhalation of ketone vapors. NIH Bulletin 176:1-66.