3-methylpent-3-en-2-one

Endpoint summary

Key value for chemical safety assessment

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Justification for selection of repeated dose toxicity inhalation - systemic effects endpoint:
Read across to CAS # 141-79-7, EC # 205-502-5, 4-Methylpent-3-en-2-one, Mesityl Oxide:
1)Key experimental study conducted according OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test) in 1992. In summary, exposure to 302, 103, or 31 ppm of the test substance was associated with a concentration-dependent lower feed consumption, body weight, and body weight gain; clinical abnormalities and nasal passage pathology in the test groups were consistent with exposure to an irritating vapor. Thus, a lowest-observed- adverse-effect level (LOAEL) for toxicity was determined to be 31 ppm based on effects on feed consumption, body weights, body weight gain, and nasal passage histopathology.
2) Experimental result from publication from 1939, The toxicity of mesityl oxide. When mice inhaled 1.3% mesityl oxide, 15 minutes/day for 5 days, none died; however, after 11 days, three of the ten mice studied died. When ten mice inhaled 1.3% mesityl oxide for 30 minutes/day, all of the mice had died by day 6. Gross necropsy and histopathologic examination revealed pulmonary hemorrhage, renal tubular degeneration, distention of the gastrointestinal tract, and hepatic necrosis. The authors concluded that 0.7% mesityl oxide was the maximum concentration which could be inhaled by mice without fatalities.
3) Experimental result from publication from 1939, The toxicity of mesityl oxide. Rabbits could tolerate repeated exposures to 1.3% mesityl oxide in air for 30 minutes/day without dying; however, inhalation of 1.3% mesityl oxide for 60 minutes/day for 10 days caused spastic paralysis and death within 7 to 11 days after the onset of paralysis.
4) Supporting study, response of guinea pigs and rats to repeated inhalation of vapors of mesityl oxide and isophorone , 1942. Pathologic changes, observed at all concentrations except 50 ppm. The frequency and intensity of these changes were concentration dependent.