Cosmetic products containing benzalkonium chloride (BAK) and formaldehyde (FA) preservatives are toxic to ocular cells, a recent study found. These preservatives are found in many common cosmetic products such as mascara, eye shadow, eyeliner and eye makeup remover.1
Researchers tested the influence of BAK and FA on the morphology, survival, and proliferation and signaling ability of meibomian gland, corneal and conjunctival epithelial cells. Results show that both preservatives cause dose-dependent changes in the morphology, survival and proliferation of all types of cells tested. “Many of the concentrations tested induced cell atrophy, poor adherence, decreased proliferation and death after five days of exposure,” the study said. “Our results demonstrate that the cosmetic preservatives, BAK and FA, exert many toxic effects on human ocular cells.”1
While BAK commonly used in topical glaucoma medications is known to disrupt tear film homeostasis by stripping away the lipid layer, this study sheds further light on the preservative’s use in cosmetic eye products and possible ill effects.2
1. Chen X, Sullivan DA, Sullivan AG, et al. Toxicity of cosmetic preservatives on human ocular surface and adnexal cells. Exp Eye Res. 2018;170:188-97.