Occurrence of cyclic and linear siloxanes in indoor air from Albany, New York, USA, and its implications for inhalation exposure.

Cyclic and linear siloxanes are used in a wide variety of household and consumer products. Nevertheless, very few studies have reported the occurrence of these compounds in indoor air or inhalation exposure to these compounds. In this study, five cyclic (D3-D7) and nine linear siloxanes (L3-L11) were determined in 60 indoor air samples collected in Albany, New York, USA. The mean concentrations of individual siloxanes in particulate and vapor phases ranged from <12 μg g(-1) (for octamethyltrisiloxane [L3], decamethyltetrasiloxane [L4]) to 2420 μg g(-1) (for decamethylcyclopentasiloxane [D5]) and from 1.05 ng m(-3) to 543 ng m(-3), respectively. The mean concentrations of individual siloxanes in combined particulate and vapor phases of bulk indoor air ranged from 1.41 ng m(-3) (for L4) to 721 ng m(-3) (for D5). Cyclic siloxanes hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), D5, dodecamethylcyclohexasiloxane (D6), and octadecamethylcycloheptasiloxane (D7) were found in all indoor air samples. The mean concentrations of total siloxanes (i.e., sum of cyclic and linear siloxanes) ranged from 249 ng m(-3) in laboratories to 6210 ng m(-3) in salons, with an overall mean concentration of 1470 ng m(-3) in bulk indoor air samples. The calculated mean daily inhalation exposure doses of total siloxanes (sum of 14 siloxanes) for infants, toddlers, children, teenagers, and adults were 3.18, 1.59, 0.76, 0.34, and 0.27 μg/kg-bw/day, respectively.