Parabens

Parabens are preservatives used in a wide range of cosmetic products, including products for children, and some are permitted in foods. However, there is concern for endocrine disrupting effects. This paper critically discusses the conclusions of recent reviews and original research papers and provides an overview of studies on toxicokinetics. After dermal uptake, parabens are hydrolyzed and conjugated and excreted in urine. Despite high total dermal uptake of paraben and metabolites, little intact paraben can be recovered in blood and urine. Paraben metabolites may play a role in the endocrine disruption seen in experimental animals and studies are needed to determine human levels of parabens and metabolites. Overall, the estrogenic burden of parabens and their metabolites in blood may exceed the action of endogenous estradiol in childhood and the safety margin for propylparaben is very low when comparing worst-case exposure to NOAELs from experimental studies in rats and mice.

Background: Little information is available on the content of bisphenol A (BPA) and other endocrine-disrupting chemicals (EDCs) such as parabens in infant textiles and clothes. Objectives: 1) To determine the concentrations of BPA and parabens in socks for infants and young children purchased in Spain, 2) to assess the (anti-)estrogenicity and (anti-)androgenicity of extracts from the socks, and 3) to estimate dermal exposure doses to these chemicals. Methods: Thirty-two pairs of socks for infants and young children (1-48 months) were purchased from 3 stores in Granada (Spain). Textile material was cut from the foot, toe, and leg of each sock (n = 96 samples) for chemical analysis. Hormone-like activities were determined in foot sections (n = 32 samples) by using the E-Screen assay for (anti-)estrogenicity and PALM luciferase assay for (anti-)androgenicity. Results: BPA was present in 90.6% of samples at concentrations ranging from < 0.70 to 3736 ng/g. BPA levels were around 25-fold higher in socks from store 1, which had a higher cotton content compared to stores 2 and 3. Ethyl-paraben was found in 100% of samples, followed by methyl-paraben (81.0%), and propyl-paraben (43.7%). No butyl-paraben was detected in any sample. Estrogenic activity was detected in 83.3% of socks from store 1 (range = 48.2-6051 pM E 2 eq/g) but in only three socks from stores 2 and 3. Anti-androgenic activity was detected in six of the 32 socks studied (range = 94.4-2989 μM Proceq/g), all from store 1. Estimated dermal exposure to BPA was higher from socks for children aged 36-48 months (median = 17.6 pg/kg/day), and dermal exposure to parabens was higher from socks for children aged 24-36 months (median = 0.60 pg/kg/day). Discussion: This is the first report in Europe on the wide presence of BPA and parabens in socks marketed for infants and children. BPA appears to contribute to the hormone-like activity observed in sock extracts.

A method for simultaneous determination four paraben preservatives in cosmetics by using fast isocratic high-performance liquid chromatography was developed. Methyl paraben (MP), ethyl paraben (EP), propylparaben (PP), and butyl paraben (BP) were analyzed on a Chromolith reversed-phase 18e column (50 mm x 4.6 mm) using isocratic elution with acetonitrile and water (32:68 v/v), and the flow rate was set at 3.00 mL min –1. Under these optimal conditions, all analyte peaks were baseline separated with a run time of 2 min. The linearity ranges for calibration curves were 0.05-8.00 mg L –1 for MP and EP, 0.10-10.00 mg L –1 for PP, and 0.20-10.00 mg L –1 for BP with a R 2 more than 0.9995 for all analytes. The limits of detection (0.01-0.06 mg L –1) and quantification (0.03-0.18 mg L –1) for the analytes were obtained. The purposed method was successfully applied to determine the paraben preservatives in cosmetic samples. The cosmetic samples were prepared by ultrasonic extraction using acetonitrile with recoveries ranging from 96-105%.