Quaternium-15

Quaternium-15 (systematic name: hexamethylenetetramine chloroallyl chloride) is a quaternary ammonium salt used as a surfactant and preservative in many cosmetics and industrial substances. It is an anti-microbial agent by virtue of being a formaldehyde releaser, however this can also cause contact dermatitis, a symptom of an allergic reaction, especially in those with sensitive skin.