Methyl tertiary-butyl ether mode of action for cancer endpoints in rodents.
There are no reports of studies that evaluate if methyl tertiary-butyl ether (MTBE) exposure causes cancer in humans. This evaluation of MTBE carcinogenicity is based on the results of animal studies. A weak tumorigenic response was reported for both MTBE and TBA in one tumor type (kidney) in male rats, for MTBE in one other tumor type (testicular) in male rats, for MTBE in one tumor type (liver) in female mice, and for TBA in one tumor type (thyroid) in female mice. The weight of the evidence does not support a genotoxic mode of action (MOA). Non-genotoxic MOAs have been demonstrated or suggested that correspond to the weak tumorigenic responses. These MOAs either do not occur in humans or humans are much less susceptible to these effects. It is, therefore, unlikely that humans would be exposed to sufficient levels of MTBE to cause these tumorigenic responses.
Cruzan
George
G
ToxWorks, Bridgeton, NJ, USA.
Borghoff
Susan J
SJ
de Peyster
Ann
A
Hard
Gordon C
GC
McClain
Michael
M
McGregor
Douglas B
DB
Thomas
Michael G
MG
D000818:Animals; D015197:Carcinogenicity Tests; D002273:Carcinogens / Q000008:administration & dosage / Q000633:toxicity*; D023381:Endpoint Determination; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage / Q000633:toxicity*; D051379:Mice; D009152:Mutagenicity Tests; D009369:Neoplasms / Q000139:chemically induced; D011237:Predictive Value of Tests; D051381:Rats; D012737:Sex Factors; D013045:Species Specificity
D002273:Carcinogens; D008738:Methyl Ethers; C043243:methyl tert-butyl ether