"Possible cosmetic irritant" refers to a substance that has the potential to cause irritation or allergic reactions when applied to the skin or other body surfaces. 

In cosmetic products, these substances may include fragrances, preservatives, dyes, or other ingredients to which some people may be sensitive. 

Although not all people may experience irritation from these substances, some compounds have the potential to cause discomfort, redness, itching, or other adverse reactions in some individuals. 

Cosmetic manufacturers often label products with potential irritants to inform consumers and enable them to make informed choices based on their sensitivities and preferences.