………a three-year debate over the need to regulate decamethylcyclopentasiloxane, also known as D5, ended when federal Environment Minister Peter Kent concluded that it does not harm the environment.
D5 and related siloxanes are noted for their ability to provide a quick-drying, non-oily feel to everything from shampoo to sunscreen. In January 2009, a screening assessment, conducted as part of Canada’s ongoing Chemicals Management Plan, flagged D5 as potentially harmful to the environment. However, in July 2009 the Silicones Environmental, Health and Safety Council of North America submitted a Notice of Objection. In response to this, then-environment minister Jim Prentice established a scientific board of review to look into the matter. The board issued its report last fall.
The Report of the Board of Review for Decamethylcyclopentasiloxane (Siloxane D5) concluded that, due to its high vapour pressure, D5 tends to partition primarily into air, where it is quickly degraded into harmless compounds by indirect photolysis. Although it can persist in sediments and accumulate in sediment-dwelling organisms, it does not biomagnify through the food chain. The report noted that “siloxane D5 will not accumulate to sufficiently great concentrations to cause adverse effects in organisms in air, water, soils, or sediments.”
Source: The Canadian Chemical News (Canadian Society for Chemistry))