Abstract and Introduction
Background: The systemic toxicity of phthalates has been extensively reported. Although rarely sensitizing, phthalates have been implicated in promoting the development of both atopy and contact dermatitis in animal models. Dermal absorption of phthalates may contribute to overall chemical burden. Infants may be particularly susceptible to chemical exposures. Baby skin care products may be a significant source of phthalate exposure.
Objective: We measured the phthalate content of 30 skin care products intended for babies and children.
Methods: Nineteen leave-on and 11 wash-off baby skin care products were analyzed for 17 unique phthalates by an independent laboratory using standard gas chromatographic mass spectrometry.
Results: Of 30 products tested, four had phthalate levels above the reporting limit (0.1–0.5 ppm); of these, only one had levels above 1 ppm (44 ppm). There was no statistical significance of phthalate detection in leave-on versus wash-off products (p = .578).
Conclusion: The majority (26 of 30) of the baby skin care products analyzed did not have detectable phthalate levels. Four products had detectable phthalate levels. In baby skin care products, levels of the 17 phthalates tested are low overall, but occasional products may contain higher phthalate levels. Monitoring products to ensure safety standards are met may be warranted.
Phthalates are man-made esters of phthalic acid and are used in many industries. Their use adds flexibility, durability, and transparency to plastic (usually polyvinyl chloride). Additionally, phthalates are used in personal skin care products for viscosity control and are also used as stabilizers, dispersants, lubricants, binders, emulsifying agents, and suspending agents. Although rarely listed as ingredients, phthalates have been detected in numerous adult skin care products.[1,2] Their presence has been attributed to contaminants, to part of the "fragrance" in the ingredient list, or to by-products of manufacturing.
In the last decade, there has been increasing public concern about environmental exposure to phthalates,[3–5] given their association with systemic toxicity in both animal and in vitro studies.[6–20] For example, there has been a correlation between phthalates and toxic effects on the genitourinary system from di-n-butyl hthalate (DnBP) in rats, as well as from diethyl phthalate (DEP), mono-n-butyl phthalate (MBP), monobenzyl phthalate (MBzP), and monoisobutyl phthalate in humans. Studies have noted reproductive-system effects in rats from DnBP and bis(2-ethylhexyl) phthalate (DEHP),[10–12] in mice offspring from DEP, and in humans from DnBP and DEHP as well as DEP, MBP, and MBzP.[15,16] Cardiopulmonary-system consequences have been reported with exposure to mono-2-ethylhexyl phthalate in vitro and to DEHP in rats.[18,19] DEHP has also been documented to affect the rat gastrointestinal system.[10,20]
There are also data to support dermatologic manifestations of phthalate exposure. Contact urticaria from DEHP following exposure to polyvinyl chloride–coated cotton gloves and to a work uniform has been described. Although phthalates are not highly sensitizing, reports of allergic contact dermatitis from phthalates have been published.[24–33] There is evidence that DnBP promotes susceptibility to (and development of) contact dermatitis in mouse models. Atopic dermatitis–like lesions in mice have also reportedly been exacerbated by exposure to DEHP at low concentration levels and also by exposure in utero, suggesting that widespread exposure to phthalates may play a role in the increasing prevalence of atopic dermatitis.
Human exposure to phthalates is extensive; in the 1999-to-2000 United States National Health and Nutrition Examination Survey, at least one phthalate urinary metabolite was detected in 99% of the 2,540 adult urine samples analyzed. As a result of the current public health concern, the Consumer Product Safety Improvement Act was passed by Congress in 2008, banning several common phthalates, DEHP, DnBP, n-butyl benzyl phthalate, diisononyl phthalate, diisodecyl phthalate, and di-n-octyl phthalate in concentrations greater than 0.1% in any children's toy or child care articles such as teethers.
Additionally, it has been proposed that dermal absorption of phthalates may contribute to the overall chemical burden of exposure.[37,38] Sathyanarayana and colleagues measured nine phthalate metabolites in the urine of 163 infants and reported a significant correlation between the application of lotions, powders, and shampoo products in the 24 hours prior to collection and increased urinary phthalate concentrations. This association was even stronger in younger infants and increased with the number of products applied. With their developing livers and a unique ratio of surface area to volume, infants may be a particularly susceptible population with regard to dermal absorption of chemicals.[40,41]
At the time of this study, there were no published studies evaluating baby skin care products for the presence of phthalates. This study sought to determine if phthalates are present in baby skin care products, including leave-on, wash-off, and "soaking" products (ie, products—such as bubble baths—that are intended as wash-off products but that may in practice entail longer skin exposures).
Dermatitis. 2011;22(05):272-276. © 2011 American Contact Dermatitis Society