5df75927_r_Batch_7___Environment_Canada__Response
[Comment] There is a need for a clear explanation for taking a threshold approach to the effects of isophorone. [Response] 
Although the mode of induction of tumours is not fully elucidated, the tumours observed are not considered to have resulted from direct interaction with genetic material. Therefore, a threshold approach is used to assess risk to human health.
Summary of Public Comments received on the Challenge substance Isophorone (CAS 78-59-1) Draft Screening Assessment Report for Batch 7 - Environment Canada
Response