Phthalate and Organophosphate Plasticizers in Nail Polish: Evaluation of Labels and Ingredients

In the 2000s, nail polish manufacturers started promoting "3-Free" products, phasing out three widely publicized toxic chemicals: toluene, formaldehyde, and dibutyl phthalate (DnBP). However, DnBP was sometimes replaced by another endocrine-disrupting plasticizer, triphenyl phosphate (TPHP). Many new " n-Free" labels have since appeared, without any standardization on which n chemicals are excluded. This study aimed to compare measured plasticizer content against nail polish labels. First, we summarized definitions of labels. Then, we measured 12 phthalate and 10 organophosphate plasticizers in 40 nail polishes from 12 brands selected for popularity and label variety. We found labels ranging from 3- to 13-Free; 10-Free was the most inconsistently defined (six definitions). Our samples contained TPHP and bis(2-ethylhexyl) phthalate (DEHP) at up to 7940 and 331 μg/g, respectively. The 5- to 13-Free samples had lower TPHP levels than unlabeled or 3-Free samples (median <0.002 vs 3730 μg/g, p < 0.001). The samples that did not contain TPHP had higher DEHP levels (median 68.5 vs 1.51 μg/g, p < 0.05). We measured plasticizers above 100 μg/g in five brands that did not disclose them and in two that excluded them in labels. This study highlights inconsistencies in nail polish labels and identifies TPHP and DEHP as ingredient substitutes for DnBP.