Me-acr can be absorbed totally after dermal, and oral exposure. Me-acr is metabolized fairly rapidly and elimination occurs for a large part via exhalation of CO2 and to a lesser extent via urinary excretion of thio-ethers. Me-acr is irritant to corrosive to the skin. Skin sensitization and cross sensitization to some of the related compounds occurs. In a two-year inhalatory study in rats (highest dose tested: 483 mg/m3) no signs of systemic toxicity or carcinogenicity are observed. Dose-related changes are observed in the nasal mucosas. The lowest dose tested (54 mg/m3 = 15 ppm) induces a slight effect on the respiratory and olfactory nasal mucose. Me-acr induces mutations and chromosomal aberrations in mammalian cells in vitro. However, in view of the abovementioned local effects these results are considered irrelevant for the MAC evaluation. Since rats ar obligatory nasal breathers this region has a higher sensitivity and this fact has little significance for the extrapolation to humans. To take into account intraspecies variation a safety factor of 3 is introduced. An occupational exposure limit of 18 mg/m3 (5 ppm) TWA 8 hr is recommended. Since dermal absorption can add to the inhalatory exposure a "H" (skin notation ) is advised.
|Number of pages||27|
|Publication status||Published - 1990|