User Guide to Thresholds and Classification - Environmental ...

208User Guide for Thresholds and Classifications2 Minimum degrees of hazard(1) A substance with toxic properties is not hazardous for the purposes of the Act unless—…(m) data for the substance indicates evidence of mutagenic effects as a result of mammalianin vivo exposure to the substance; or(n) data for the substance indicates evidence of—i. genotoxic effects as a result of mammalian in vivo exposure to the substance; andii. mutagenic effects as a result of in vitro exposure to the substance; or(o) data for the substance indicates evidence of mutagenic effects as a result of in vitroexposure of mammalian cells to the substance and the substance has a structure-activityrelationship to known germ cell mutagens, where—i. structure-activity relationship means a significant correlative relationship between thechemical structure of the substance and the chemical structure of a known germ cellmutagen; andii. the relationship relates to that germ cell mutagenic activity.14.2.2. Mutagenicity classification criteria for substancesSchedule 4 to the Hazardous Substances Classification Regulations 2001 identifies two classificationcategories for substances that are mutagenic (subclass 6.6).Category 6.6A – substances that are known or presumed human mutagensa. A substance for which data indicate a causal relationship between the exposure of humans to thesubstance and the induction of heritable mutagenic effects in the germ cells of humans.b. A substance for which data indicate evidence of heritable mutagenic effects in the germ cells ofmammals as a result of in vivo exposure to the substance.c. A substance for which data indicate, as a result of in vivo exposure to the substance:i. evidence of mutagenic effects in the somatic cells of mammals; andii.evidence that the substance has the potential to cause mutagenic effects in germ cells ofmammals (including evidence of genotoxic effects in germ cells or evidence of the ability of thesubstance or its metabolites to interact with the genetic material of germ cells).d. A substance for which data indicate evidence of mutagenic effects in the germ cells of humans as aresult of exposure to the substance without evidence of transmission to progeny (including an increasein the frequency of aneuploidy in sperm cells of exposed humans).Category 6.6B – substances that are suspected human mutagensa. A substance for which data indicate evidence of mutagenic effects in the somatic cells of mammals asa result of in vivo exposure to the substance.January 2012 EPA0109