2. Steer clear of ‘the big three’ Lacquered nails can look lovely, but you may want to kick your favorite color to the curb: Ingredients in conventional nail polishes might harm your health. Steer clear of ‘the big three’: formaldehyde, dibutyl phthalate and toluene. These chemicals have been shown to cause dermatitis, disrupt hormones and affect the nervous system. Brands to try: Deborah Lippmann, Zoya, and Mineral Fusion.