Full length articleOccurrence of organophosphorus flame retardants on skin wipes: Insight into human exposure from dermal absorption

- PFR levels varied at different skin locations with palms > back-of-hands > forearms.
- TCEP and ∑ TCPP levels were strongly reliable in three repeated measurements.
- Hand-washing removed > 50% of PFRs on hands.
- Indoor dust contributed a little to PFRs on hands.
- Dermal absorption is a potential significant pathway for PFR exposure.

This study surveyed occurrences and influencing factors of organophosphorus flame retardants (PFRs) on skin surface. Skin wipe samples from palms, back-of-hands and forearms of 30 adults were collected by using gauze pads soaked in isopropyl alcohol in Beijing, China. Tris(chloropropyl) phosphate isomers (∑ TCPP), tris(2-chloroethyl) phosphate (TCEP) and triphenyl phosphate (TPHP) were the most abundant compounds with detection frequencies higher than 97%. ∑ TCPP showed the highest mean level (4.6 μg/m2), followed by TPHP (2.4 μg/m2) and TCEP (1.6 μg/m2). Levels on palms were slightly higher than on back-of-hands, and both were substantially higher than those on forearms. TCEP and ∑ TCPP levels were strong reliable in three repeated measurements from 4 participants over a three month period (intraclass correlation of coefficient of 0.91 and 0.95, respectively), while TPHP levels were not. Washing with soap and water removed a large fraction of PFRs on hands with median reduction of 76, 72 and 67% for TCEP, ∑ TCPP and TPHP, respectively. Paired dust samples, table surface wipe and hand wipe samples were collected from 17 offices (13 surface wipes and 22 hand wipes) in Beijing. Hand wipe TCEP, ∑ TCPP and TPHP were neither correlated with dust samples nor with table surface wipe samples. Two methods were used for dermal exposure assessments. The estimated lower median total exposure from palms, back-of-hands and forearms by the relative absorption method were 0.6, 1.0, 0.3 ng/kg BW-d for TCEP, ∑ TCPP and TPHP, respectively. These estimates were in the same range as those via dust ingestion for adults in Beijing, suggesting dermal absorption is likely a significant pathway of human PFR exposure.

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