title: Methylsiloxanes in children silicone-containing products from China: Profiles, leaching, and children exposure.
abstract: Methylsiloxanes (D4-D6, L5-L16) were detected in children silicone-containing products (n=190, detected frequencies=46-89%) marketed in China. For the 15 target compounds, the average concentrations ranged from <LOQ - 0.005±0.007μg/g in hard toys, 0.084±0.281-22.2±29.6μg/g in pacifiers, 0.020±0.023-20.6±16.0μg/g in teethers, and 0.005±0.009-2.81±3.22μg/g in soft rubber toys. Linear methylsiloxanes were predominant in these four types of children products. In the leaching test, except for L6, the other 14 methylsiloxanes were detected (mean=0.001±0.008-0.770±2.60ng/mL) in saliva leachates for children products, with the detection frequencies ranging from 4 to 46%. The conservative mouthing exposure for children were 6.87-18.05ng/kg bw-day via pacifiers and 0.44-2.29ng/kg bw-day via teether/soft rubber toys for ∑cyclic methylsiloxanes, and 7.89-20.74ng/kg bw-day via pacifiers and 0.41-2.12ng/kg bw-day via teether/soft rubber toys for ∑linear methylsiloxanes. Methylsiloxanes conservative mouthing exposure associated with children products were 1-2 order of magnitudes lower than the sum of children's daily inhalation exposure and dust ingestion exposure in the indoor environment. The above results indicated that although methylsiloxanes, as the impurities of polydimethylsiloxane, distributed in children silicone-containing products, exposure arising from directly mouthing these products may not be the dominated pathway for children exposure of methylsiloxanes.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Liqin
authors.initials: L
authors.lastname: Zhi
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Science, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China; Institute of Environment and Health, Jianghan University, Wuhan 430056, China. Electronic address: caiyaqi@rcees.ac.cn.
authors.forename: Yaqi
authors.initials: Y
authors.lastname: Cai
mesh_terms: D002648:Child; D000067576:Child Health; D002681:China; D004781:Environmental Exposure / Q000032:analysis; D004785:Environmental Pollutants / Q000032:analysis* / Q000737:chemistry; D005260:Female; D006801:Humans; D008297:Male; D041361:Pacifiers; D010988:Play and Playthings; D012463:Saliva / Q000737:chemistry; D012833:Siloxanes / Q000032:analysis* / Q000737:chemistry
chemical_list: D004785:Environmental Pollutants; D012833:Siloxanes
keywords: Children silicone-containing product; Leaching test; Methylsiloxane; Mouthing exposure