Why bring this IARC list up out of the blue? The parent comment mentioned an EPA classification and you brought up a list of IARC classifications. The EPA and IARC frequently disagree on their classifications.
The two categories are very similar, they are sort of aimed at the same result but have slightly different criteria. e.g. the EPA considers exposure levels, IARC requires at least some human evidence. So you wouldn't say one is stricter than the other, just different ways of skinning a cat.