Thirty skin care products intended for infants and children were purchased from an independent infant-focused retail store. In regard to selection methodology, an attempt was made to obtain at least one product from each manufacturer available, and an adequate representation of diverse product types was intended. These included 19 leave-on products and 11 wash-off products from a variety of manufacturers. Each product was categorized as body wash, baby bath, moisturizer, sunscreen, or diaper cream (Table 1). The products were shipped in their original containers to an independent laboratory (Analytical Sciences, Petaluma, CA), where phthalate analysis was performed. For each product, 0.5 to 1.0 g of the sample was carefully weighed to the nearest tenth of a milligram (ie, ± 0.0001 g) in a 40 mL vial. Exactly 10 mL of clean hexane was added to each sample vial, which was then sealed with a polytetrafluoroethylene-lined cap. The vials were mixed with a vortex mixer and placed (sealed) into a sonication bath for 30 minutes. After extraction by sonication, the vials were allowed to stand for at least 2 hours, at which point a portion of the hexane solvent extract was removed and placed into a sealed autosampler vial for analysis by gas chromatographic mass spectroscopy (GC/MS). In some cases, a dilution was used in the initial analysis owing to the overall hydrocarbon content expected in the original sample, and the reported detection limit (RDL) increased by the dilution factor.
The GC/MS instrument was optimized and calibrated for 17 specific phthalate compounds prior to the analysis of the extracted skin care products (Table 2). The phthalate compounds in the analyzed products were identified and quantitated by the GC/MS software. Results were reported in units of parts per million (ppm) or milligrams per kilogram of phthalate present in the analyzed product.
Dermatitis. 2011;22(05):272-276. © 2011 American Contact Dermatitis Society