User Guide to Thresholds and Classification - Environmental ...

164User Guide for Thresholds and Classifications11.2.2. Skin corrosion or irritation classification criteria for substancesSkin corrosionSchedule 5 to the Hazardous Substances (Classification) Regulations 2001 identifies three classificationsubclasses for substances that are corrosive to skin (subclass 8.2) as follows.Subclass 8.2 – substances that are corrosive to dermal tissueA subclass 8.2 classification and one of the subsequent three categories apply to any substance thatmeets the following criteria.a. Category 8.2AA substance for which data indicate irreversible destruction of dermal tissue, which destruction isvisible necrosis through the epidermis and into the dermis, within 1 hour following exposure to thesubstance for less than or equal to 3 minutes in greater than or equal to 33% of exposures as aresult of exposure to the substance.b. Category 8.2BA substance for which data indicate irreversible destruction of dermal tissue, which destruction isvisible necrosis through the epidermis and into the dermis, within 14 days following exposure to thesubstance for greater than 3 minutes, but not more than 1 hour, in greater than or equal to 33% ofexposures as a result of exposure to the substance.c. Category 8.2CA substance for which data indicate irreversible destruction of dermal tissue, which destruction isvisible necrosis through the epidermis and into the dermis, within 14 days following exposure to thesubstance for greater than 1 hour, but not more than 4 hours, in greater than or equal to 33% ofexposures as a result of exposure to the substance.Skin irritationSchedule 4 to the Hazardous Substances Classification Regulations 2001 identifies two classificationcategories for substances that are skin irritants (subclass 6.3) as follows.Category 6.3A – substances that are irritating to the skina. A substance for which reversible adverse effects on dermal tissue are evidenced by data indicating amean Draize score greater than or equal to 2.3, but less than or equal to 4.0, for either erythema oreschar or oedema, as a result of exposure to the substance.b. A substance for which data indicate skin inflammation, including alopecia over a limited area,hyperkeratosis, hyperplasia, and scaling, that persists for 14 days following exposure to thesubstance in at least 66% of exposures, as a result of exposure to the substance.c. A substance for which data indicate a pronounced variability of adverse effects between and withintest exposures, even though the effects of exposure to the substance do not meet the criteria in (a)or (b), or for hazard classification 6.3B.January 2012 EPA0109