The contamination of n-nitrosamines in cosmetics has been
raised as a serious concern due to their carcinogenicity, which are
capable of penetrating the skin and causing cancer in laboratory
animals [1]. Contamination by n-nitrosamines in cosmetic products
has become an issue since the 1970s and cosmetics containing
n-nitrosamines have been subjected to enforcement action
in the USA [2].
N-nitrosamines in cosmetics are formed by the reaction products
of amines or amine derivatives with nitrosating agents such
as nitrous acid (HONO), nitrites, or oxides of nitrogen as described
in Eq. 1,
[3].