Survey of Organosilicone Compounds, Including Cyclic and Linear Siloxanes, in Personal-Care and Household Products Yuichi Horii Æ Kurunthachalam Kannan Received: 13 February 2008 / Accepted: 31 March 2008 / Published online: 29 April 2008 Ó Springer Science+Business Media, LLC 2008 Abstract The determination of organosiloxanes in con- sumer products is important for the evaluation and characterization of sources of human and environmental exposures. In this study, we determined concentrations of cyclic siloxanes [octamethylcyclotetrasiloxane (D 4 ), deca- methylcyclopentasiloxane (D 5 ), dodecamethylcyclohexasil- oxane (D 6 )], tetradecamethylcycloheptasiloxane (D 7 )] and linear siloxanes (L 4 to L 14 ) in a variety of consumer products (n = 76), including hair-care products, skin lotions, body washes, cosmetics, nursing nipples (i.e., pacifiers), cook- ware, and household sanitation products such as cleansers and furniture polishes, using gas chromatography–mass spectrometry with selected ion monitoring. Prior to the analysis of samples, a method was developed to reduce the contamination arising from organosiloxanes present in cer- tain gas chromatograph (GC) parts, such as the inlet septum; use of a Restek BTO septum at an inlet temperature of 200°C gave the lowest background level (D 4 : 0.8 pg; D 5 : 0.3 pg; D 6 : 0.2 pg). Concentrations of cyclic siloxanes in consumer products analyzed ranged from \ 0.35 to 9380 lg/g, from \ 0.39 to 81,800 lg/g, from \ 0.33 to 43,100 lg/g, and from \ 0.42 to 846 lg/g for D 4 ,D 5 ,D 6 , and D 7 , respectively. Concentrations of linear siloxanes varied from \ 0.059 to 73,000 lg/g. More than 50% of the samples analyzed contained D 4 ,D 5 , or D 6 . Cyclic siloxanes were predominant in most of the sample categories; D 5 was predominant in hair-care products, skin lotions, and cos- metics; D 6 or D 7 was predominant in rubber products, including nipples, cookware, and sealants. Potential daily exposure to total organosiloxanes (sum of cyclic and linear siloxanes) from the use of personal-care products by adult women in the United States has been estimated to be 307 mg. Significant positive correlations (p \ 0.01) existed in our study between D 4 and D 7 ,D 4 and linear siloxanes, D 5 and D 6 , and D 5 and linear siloxanes. The correlations can be related to the composition of organosiloxanes used in con- sumer products. The results of our study suggest that a wide variety of consumer products that are used on a daily basis contain cyclic and linear siloxanes and these products can contribute considerably to human exposures. Introduction Over the last three decades, organosiloxanes (silicones) such as cyclic siloxanes and polydimethylsiloxane (PDMS; linear siloxane) have been widely used in consumer prod- ucts such as electronics, furniture, health-care products, cosmetics, cookware, and medical devices because sili- cones have low surface tension, high thermal stability, and smooth texture and are believed to be inert. Silicones are polymeric organic silicon, consisting of a backbone of alternating silicon–oxygen [Si–O] units with organic side chains attached to each silicon atom (Hobson et al. 1997). Annual production of octamethylcyclotetrasiloxane (D 4 , where D refers primarily to the dimethylsiloxane unit and the subscript refers to the number of Si–O bonds that make up the chain), which is used as a base material for the production of polymeric silicones, is 100–500 million pounds/year (http://www.ewg.org/reports/cheminventory). Reports suggest that cyclic siloxanes have direct or indirect toxic effects such as estrogen mimicry, connective tissue Y. Horii Á K. Kannan (&) Wadsworth Center, New York State Department of Health, Department of Environmental Health Sciences, School of Public Health, State University of New York at Albany, Empire State Plaza, PO Box 509, Albany, NY 12201-0509, USA e-mail: kkannan@wadsworth.org 123 Arch Environ Contam Toxicol (2008) 55:701–710 DOI 10.1007/s00244-008-9172-z