10712
Emerging evidence suggests that the model alkylating agents methyl - and ethylmethanesulfonate and methylnitrosourea ( MNU ) and ethylnitrosourea observe a nonlinear dose - response with a no observed genotoxic effect level ( NOGEL ) .
 Chemical: methyl; Chemical: ethylmethanesulfonate; Chemical: methylnitrosourea; Chemical: MNU; Chemical: ethylnitrosourea
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: methyl; Chemical: ethylmethanesulfonate; Chemical: methylnitrosourea; Chemical: MNU; Chemical: ethylnitrosourea