Formaldehyde in "nontoxic" Nail Polish

Background: Nail polish is known to contain potentially hazardous chemicals that have been linked to adverse health effects after overexposure. Formaldehyde is used as an antimicrobial, preservative, and nail hardener in select nail products, yet it is a recognized carcinogen and potent allergen in allergic contact dermatitis. Objective: The aim of this study was to investigate whether formaldehyde is present in nail polishes marketed as formaldehyde-free. Methods: Twenty-nine cosmetic nail polishes were purchased for analysis; of these, 28 were advertised as formaldehyde-free and/or did not declare formaldehyde in their ingredient lists. Initial testing was pursued using the chromotropic acid method, which uses a red-purple color change to indicate the presence of formaldehyde. Products were subsequently analyzed at least twice using high-performance liquid chromatography, quantifying formaldehyde amount above the detection limit of 2 ppm. Conclusions: High-performance liquid chromatography analysis found 5 of 29 products containing formaldehyde, 4 of which were advertised as formaldehyde-free. All other products were negative for formaldehyde (