title: Aggregate dermal exposure to cyclic siloxanes in personal care products: implications for risk assessment.
abstract: Consumers who use personal care products (PCPs) are internally exposed to some of the organic components present of which some may be detected in exhaled air when eliminated. The aim of this study was the quantitative determination of octamethylcyclotetrasiloxane (D4) and decamethylcyclopentasiloxane (D5) in end-exhaled air to study dermal absorption of substances in PCPs. We exposed the forearm of fifteen healthy volunteers for 60min to pure D4 or D5 and to commercial products containing D4 and D5. Inhalation uptake was kept to a minimum by keeping the forearm in a flow cabinet during dermal exposure and supplying filtered air to the breathing zone of the volunteer during the post-exposure period. End-exhaled air was collected using a breath sampler (Bio-VOC), transferred to carbograph multi-bed adsorbent tubes and analyzed by thermal desorption gas chromatography mass spectrometry (TD-GC-MS). In the end-exhaled air of non-exposed volunteers background concentrations of D4 (0.8-3.5ng/L) and D5 (0.8-4.0ng/L) were observed. After exposing the volunteers, the level of D4 and D5 in end-exhaled air did not or barely exceed background concentrations. At t=90min, a sharp increase of the D4/D5 concentration in end-exhaled air was observed, which we attributed to the inhalation of the substances during a toilet visit without using inhalation protection devices. When this visit was taken out of the protocol, the sharp increase disappeared. Overall, the results of our study indicate that dermal absorption of D4 and D5 contributes only marginally to internal exposure following dermal applications. As in our study inhalation is the primary route of entry for these compounds, we conclude that its risk assessment should focus on this particular exposure route.
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Jacqueline.Biesterbos@radboudumc.nl.
authors.forename: Jacqueline W H
authors.initials: JW
authors.lastname: Biesterbos
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Gwendolyn.Beckmann@radboudumc.nl.
authors.forename: Gwendolyn
authors.initials: G
authors.lastname: Beckmann
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Luuk.vanWel@radboudumc.nl.
authors.forename: Luuk
authors.initials: L
authors.lastname: van Wel
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Rob.Anzion@radboudumc.nl.
authors.forename: Rob B M
authors.initials: RB
authors.lastname: Anzion
authors.affiliation: Swiss Federal Institute of Technology Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland. Electronic address: Natalie.von.goetz@chem.ethz.ch.
authors.forename: Natalie
authors.initials: N
authors.lastname: von Goetz
authors.affiliation: Swiss Federal Institute of Technology Zürich, Vladimir-Prelog-Weg 1, 8093 Zürich, Switzerland. Electronic address: tatsiana.dudzina@chem.ethz.ch.
authors.forename: Tatsiana
authors.initials: T
authors.lastname: Dudzina
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands; Radboud university medical center, Department of Pediatrics, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Nel.Roeleveld@radboudumc.nl.
authors.forename: Nel
authors.initials: N
authors.lastname: Roeleveld
authors.affiliation: Radboud University Nijmegen, Department of Environmental Science, Institute for Wetland and Water Research, P.O. Box 9010, 6500 GL Nijmegen, The Netherlands. Electronic address: A.ragas@science.ru.nl.
authors.forename: Ad M J
authors.initials: AM
authors.lastname: Ragas
authors.affiliation: Radboud university medical center, Department of Pharmacology and Toxicology, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Frans.Russel@radboudumc.nl.
authors.forename: Frans G M
authors.initials: FG
authors.lastname: Russel
authors.affiliation: Radboud university medical center, Department for Health Evidence, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands. Electronic address: Paul.Scheepers@radboudumc.nl.
authors.forename: Paul T J
authors.initials: PT
authors.lastname: Scheepers
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D003358:Cosmetics / Q000008:administration & dosage; D020405:Dermis / Q000378:metabolism*; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D019570:Inhalation Exposure; D008297:Male; D008875:Middle Aged; D018570:Risk Assessment; D012833:Siloxanes / Q000008:administration & dosage / Q000032:analysis / Q000493:pharmacokinetics*; D012869:Skin Absorption
chemical_list: D003358:Cosmetics; D012833:Siloxanes; C114768:decamethylcyclopentasiloxane; C024064:octamethylcyclotetrasiloxane
keywords: D4; D5; Decamethylcyclopentasiloxane; End-exhaled air; Human biological monitoring; Octamethylcyclotetrasiloxane