A pilot study to characterize hand-to-mouth transfer efficiency of organophosphate flame retardants identified in infant products

Abstract

This study aimed to determine levels of flame retardants (FRs) in infant products, and to characterize potential for hand-to-mouth transfer efficiency from these products. Select FR concentrations were found in polyurethane foam (PUF) in ten infant products. We examined dermal loading and hand-to-mouth transfer efficiency by simulating handling of two products by participants (n = 9), one of which was handled with and without a fabric covering. Tris (1-chloro-2-propyl) phosphate (TCIPP) was detected in all infant products. The total TCIPP mass transferred to hands was higher for products without covers; however, the relative transfer efficiency (TE) from hands to saliva was higher after handling the product with the cover. Average TCIPP dermal loading was significantly higher without the cover, indicating that these materials may act as a barrier for FR transfer from the PUF to the skin. Estimated highest average daily TCIPP ingestion in infants and children resulting from hand-to-mouth transfer during normal use was 9390 ng/day (1570 ng/kg bw-day) for the uncovered bath product, assuming 100% TE. This study indicates that further research is needed to understand factors that influence individual variability of dermal loading and transfer efficiency, variability of FR concentrations in PUF, and to elucidate the role of fabric coverings on dermal transfer.

Keywords:

• Flame retardants
• hand-to-mouth
• oral exposure
• transfer efficiency
• dermal loading
• infant products

Disclosure statement

LG, BT, JS, CB are current or former employees of consulting firms that provide scientific advice to entities including governments, corporations, law firms, and various scientific/professional organizations. At the time of acceptance and publication, CB was employed by GZA GeoEnvironmental, Inc.; BT was employed by IBM; JS was employed by Insight Exposure and Risk Sciences; and LG was employed by Cardno ChemRisk. CB and JS have previously served as testifying experts in the area of exposure and risk assessment, but not for the specific compounds addressed in this study. This paper was prepared and written exclusively by the authors. This is contribution 4053 of the Virginia Institute of Marine Science, William & Mary.

Supplemental Material

Supplemental material for this article can be accessed at www.tandfonline.com/bher

Supplemental Table S1. Hydration Values Measured by EnviroDerm Skin Hydration Meter, SK-IV skin hydration meter, and DermaLab Trans Epidermal Water Loss

Supplemental Table S2. Surface Area of Participants' Hands (cm²)

Supplemental Table S3. Sequential Wipe Analysis

Supplemental Table S4. Exposure Categories and Parameters Used in the Exposure Assessment for Ingestion of TCIPP in Children

Supplemental Table S5. Estimated Exposure via Ingestion of TCIPP Resulting from Hand-to-Mouth Exposure in Children

Supplemental Materials: Experimental Method (PUF)

Supplemental Materials: Experimental Method (Dermal Wipes)

Additional information

Funding

No outside financial support was provided to any of the authors for preparing the manuscript. The study was funded by Cardno ChemRisk and Insight Exposure and Risk Sciences.