The categories within skin corrosion are primarily classified under Category 1, which can be further subdivided into three sub-categories based on the severity and duration of exposure:
- Category 1: Skin corrosion involves destruction of skin tissue, visible necrosis through the epidermis and into the dermis, observed in at least one tested animal after exposure up to 4 hours.
- Sub-category 1A: Corrosive responses occur in at least one animal following exposures of up to 3 minutes with observation lasting up to 1 hour.
- Sub-category 1B: Corrosive responses occur in at least one animal following exposures greater than 3 minutes and up to 1 hour, with observations up to 14 days.
- Sub-category 1C: Corrosive responses occur in at least one animal following exposures greater than 1 hour and up to 4 hours, with observations up to 14 days.
There is also Category 2 for skin irritation, which refers to reversible damage to the skin, but it is separate from the corrosion categories.
