Nail primer cosmetics: Correlations between product pH and adequacy of labeling

Background: We have previously reported on injuries suffered by young child ren exposed to methacrylic acid-containing nail primers and the need for pu blic education efforts concerning this potential household hazard. However, some primers contain alternative ingredients, which may or may not pose th e same risk; product labeling information is variable and may be confusing to consumers. Objective: To investigate the relationship between pH of diff erent primer products, product contents, and appropriateness of product lab eling and packaging. Methods: Twenty-three commercially available primers w ere grouped by product contents: (methacrylic acid vs others). Product pH w as measured and product labels were scored on 7 warning points: "poison and /or corrosive," a "caution to avoid contact and/or to use a barrier when ha ndling the product," a "skin first aid," an "eye first aid," an "ingestion first aid," a caution to "keep out of reach of children," and a "in emergen cy, contact a poison center." A summative "global hazard notification score " was calculated for each product. Data were analyzed using correlations an d the two-sample t-test. Results: None of 23 products tested were contained in a child-resistant container and none included all 7 label items. Produc t pH ranged from 1.90-8.55 (mean pH 4.59 +/- 1.99); 20 products had pH < 7. 0. Only 1 product advised, in the event of a poisoning, that a poison cente r be contacted. Of 20 acidic products, only 7 alerted users that the conten ts could cause burns. The mean global hazard notification score (MAX = 7) w as 3.6; global hazard notification score did not correlate with pH. Methacr ylic acid-containing products had a lower pH (mean 3.43 +/- 0.78) than thos e without methacrylic acid (mean 5.34 +/- 2.18), p = 0.008. When the primer bottle was separated from the rest of the packaging which comprised the ar tificial nail "kit," 50% of products lost all of their warning information. Conclusions: Most, but not all, artificial nail primers analyzed in this s tudy were highly acidic. Labeling and packaging of many nail primers are in adequate, given the potential of methacrylic acid in these products to caus e burns and the toxicity of most nail primers. We agree with the Consumer P roduct Safety Commission's recently proposed rule to require cosmetic manuf acturers to repackage methacrylic acid-containing household products in chi ld-resistant containers. We also urge manufacturers to alert consumers to t he hazards of nail primers by better labeling. Manufacturers should also in vestigate the feasibility of either substituting other chemicals or lowerin g the concentration of methacrylic acid.