Chemical Sampling Information
	Hexamethylcyclotrisiloxane
Quick Links General Description Health Factors Search    [use word(s)/phrase] Table of Contents By Name A B C D E F G H I J K L M N O P Q R S T U V W X Y Z By CAS Number General Description OSHA IMIS Code Number: M205 Chemical Abstracts Service (CAS) Registry Number: 541-05-9 Chemical Description and Physical Properties: white crystalline chunky solid molecular formula: C6H18O3Si3 molecular weight: 222.47 boiling point: 134°C flash point: 35°C melting point: 64-66°C Health Factors Potential symptoms: No human data available; INHAL. SUBACUTE (Rats): liver and kidney enlargement, centrilobular hepatocellular hypertrophy, protein droplet nephropathy; reproductive toxicity (at 2500 ppm) Health Effects: Unknown in humans. Affected organs: Liver, kidneys (in animals) Notes: OSHA does not have a PEL for this chemical, which is used primarily as an intermediate in the synthesis of other silicone materials. The NOAEL for systemic toxicity in rats inhaling hexamethylcyclotrisiloxane (D3) 6 hours/day for up to 39 days appears to be 100 ppm. Respective plasma and blood D3 levels of 2-12 ng/ml and 20-28 ng/ml were reported for 6 of 10 women with silicone implants or 2-5 years after implants were removed, whereas D3 was not detectable in plasma or blood samples from a control group. D3 was tested as a possible impurity in silicone oil associated with cataract, keratopathy, glaucoma, or retinopathy as complications of intraocular administration. However, significant increases in rabbit corneal permeability to inulin or dextran, were not proportional to the concentrations of 1, 2.5, 10 and 25 mg/ml added to an FDA-approved silicone oil used intravitreally in the treatment of retinal detachment, severe proliferative vitreoretinopathy, and cytomegalovirus retinitis. Date Last Revised: 05/24/2007 Literature Basis: Flassbeck, D., Pfleiderer, B.,Grumping, R. and Hirner, A.V.: Determination of low molecular weight silicones in plasma and blood of women after exposure to silicone breast implants by GC/MS. Anal. Chem. 73(3): 606-611, 2001. Green, K., Kearse, E.C. and Trask, D.K.: Concentration-dependent effects of silicone oil components on corneal endothelial permeability. J. Toxicol. Cutan. Ocular Toxicol. 17(2-3): 141-155, 1998. Jean, P.A., Tobin, J.M. and Plotzke, K.P.: Vapor inhalation toxicity study of hexamethylcyclotrisiloxane in the rat [Abstract]. Toxicologist 78(1-Suppl.): 204, 2004. All Trademarks are the property of their respective owners.