Preservatives in Cosmetics

Preservatives are substances added to cosmetic products for the primary purpose of inhibiting the growth of microorganisms (bacteria, yeasts, molds) to maintain product safety and extend shelf life. The regulation of preservatives in cosmetics is among the most detailed aspects of cosmetic ingredient law.

The EU regulates preservatives through a positive-list system in Annex V of EC 1223/2009. Only substances listed in Annex V may be used as preservatives in cosmetic products, each with specified maximum concentrations, product type restrictions, and labeling conditions. As of 2026, Annex V contains 57 permitted preservative entries. Notable preservatives include methylparaben (max 0.4% as acid), phenoxyethanol (max 1.0%), and benzalkonium chloride (max 0.1%).

The US does not maintain a positive list for preservatives — instead, preservatives must be safe under the general safety requirements of the FD&C Act and MoCRA. The CIR has evaluated many common preservatives and provides concentration recommendations that carry significant weight in safety substantiation.

Preservative efficacy is evaluated through challenge testing (also called preservative efficacy testing or PET), where the product is inoculated with specified microorganisms and the preservative system's ability to reduce microbial counts is measured over time. The results are assessed against criteria such as those in ISO 11930 or the USP <51> method. Preservative efficacy data supports both the PAO determination and the CPSR safety assessment.