Do metabolites of polymethylcyclosiloxanes induce physiological disorders?

Bernhard Buchter, Dr. sc. techn. Dipl. Forsting, Margrit Dunkel, BScOT AOTR


Polydimethylcyclosiloxanes are synthetic organo-silicon compounds used in everyday products. Their degradation in humans is not completely understood. Dimethylsilanediol as the final metabolite is debatable. Silicon has never been directly monitored, even though complete mineralisation to carbon dioxide and silicon dioxide is likely. The latter one is not respirable, not degradable, and hardly soluble and is hence presumably accumulated within the human body. Chemical similarity to dimethylsulfoxide suggests that dimethylsilanediol is able to penetrate the intact skin and to pass the blood-brain barrier. Degradation within the brain could lead to increased levels of formic acid and silicon deposits visible as plaques. Intermediate and final metabolites may disturb the synthesis of citrate, succinate and fumarate. They may induce and boost also many of today’s autoimmune diseases like Alzheimer’s disease, Parkinson’s disease, systemic sclerosis, amyotrophic lateral sclerosis, primary biliary cirrhosis, obesity, and multiple sclerosis. In view of the possible impact of carbon-silicon compounds on human health, their metabolic pathways have to be unambiguously elucidated based on separate directly determined mass balances of carbon and silicon.

Keywords: Alumosilicate, Alzheimer’s disease, Blood-brain barrier, Citric acid circle, Dimethylsilanediol, Dimethylsulfoxide, Diabetes mellitus, Dopamine, Formic acid, Fumarate, Mitochondria, Obesity, Parkinson’s disease, Plaques, Primary biliary cirrhosis, Psoriasis, Sclerosis


Full Text:



Horii Y, Kannan K: Survey of organosilicone compounds, including cyclic and linear siloxanes, in personal-care and household products. Arch Environ Contam Toxicol. 2008; 55(4): 701-710.

Kaj L, Schlabach M, Andersson J, et al.: Siloxanes in the Nordic Environment TemaNord. Copenhagen: Nordic Council of Ministers, 2005: 593.

Accettola F, Guebitz GM, Schoeftner R: Siloxane removal from biogas by biofiltration: Biodegradation studies. Clean Techn Environ Policy. 2008; 10(2): 211-218.

Fajgar R, Pola J: Trimethylsilylgroup migration in the Criegee intermediate of gas-phase ozonolysis of trimethylsilylethenes. Tetrahedron Lett. 2000; 41(14):2435-2438.

Graiver D, Farminer KW, Narayan R: A review of the fate and effects of silicones in the environment. J Polym Env. 2003; 11(4): 129-136.

Sabourin CL, Carpenter JC, Leib TK, et al.: Biodegradation of dimethylsilanediol in soils. Appl Environ Microbiol. 1996; 62(12): 4352-4360.

Lehmann RG, Miller JR, Collins HP: Microbial degradation of dimethylsilanediol in soil. Water Air Soil Poll. 1998; 106(1-2): 111-122.

Varaprath S, Salyers KL, Plotzke KP, et al.: Identification of metabolites of octamethylcyclotetrasiloxane (D(4)) in rat urine. Drug Metab Dispos. 1999; 27(11): 1267-1273.

Environment Canada: Screening assessment for the challenge. Decamethylcyclopentasiloxane (D5). CAS No 541-02-6, 2008. Available at Accessed January 8, 2012.

Environment Canada: Screening assessment for the challenge. Dodecamethylcyclohexasiloxane (D6). CAS No 540-97-6, 2008. Available at Accessed August 12, 2011.

Environment Canada: Screening assessment for the challenge. Octamethylcyclotetrasiloxane (D4). CAS No 556-67-2, 2008. Available at Accessed January 8, 2012.

Haustein UF, Herrmann K: Environmental scleroderma. Clin Derm. 1994; 12(3): 467-473.

Kemppainen BW, Mehta M, Stafford R, et al.: Effect of vehicle on skin penetration and retention of a lipophilic red tide toxin (PbTx-3). Toxicon. 1992; 30(8): 931-935.

Sharma T, Rawal G: Transdermal therapeutic systems: An overview. Int J Pharmac Biol Arch. 2011; 2(6): 1581-1587.

Broadwell RD, Salcman M, Kaplan RS: Morphologic effect of dimethyl sulfoxide on the blood-brain barrier. Science. 1982; 217(4555): 164-166.

Santos NC, Figueira-Coelho J, Martins-Silva J, et al.: Multidisciplinary utilization of dimethyl sulfoxide: Pharmacological, cellular, and molecular aspects. Biochem Pharmacol. 2003; 65(7): 1035-1041.

Habgood MD, Begley DJ, Abbott NJ: Determinants of passive drug entry into the central nervous system. Cell Mol Neurobiol. 2000; 20(2): 231-253.

Patel D, Chaudhary SA, Parmar B, et al.: Transdermal drug delivery system: A review. Pharma Innovation J. 2012; 1(4): 66-75.

Seelig A, Gottschlich R, Devant RM: A method to determine the ability of drugs to diffuse through the blood-brain barrier. Proc Natl Acad Sci USA. 1994; 91(1): 68-72.

Schwarzenbach RP, Gschwend PM, Imboden DM: Environmental Organic Chemistry. New York: Wiley-Interscience, 1993: 681.

Perlman F, Wolfe HF: Dimethylsulfoxide as a penetrant carrier of allergens through intact human skin. J Allergy. 1966; 38(5): 299-307.

Luzar A, Chandler D: Structure and hydrogen bond dynamics of water–dimethyl sulfoxide mixtures by computer simulations. J Chem Phys. 1993; 98: 8160-8173.

Xu S, Kropscott B: Method for simultaneous determination of partition coefficients for cyclic volatile methylsiloxanes and dimethylsilanediol. Anal Chem. 2012; 84: 1948-1955.

Henzi H: Chronic methanol poisoning with the clinical and pathologic-anatomical features of multiple sclerosis. Med Hypotheses. 1984; 13(1): 63-75.

Meléndez-Hevia E, Waddell TG, Cascante M: The puzzle of the Krebs citric acid cycle: Assembling the pieces of chemically feasible reactions, and opportunism in the design of metabolic pathways during evolution. J Mol Evol. 1996; 43(3): 293-303.

Moharregh-Khiabani D, Linker RA, Gold R, et al.: Fumaric acid and its esters: An emerging treatment for multiple sclerosis. Curr Neuropharmacol. 2009; 7(1): 60-64.

Birchall JD, Chappell JS: The chemistry of aluminum and silicon in relation to Alzheimer’s disease. Clin Chem. 1988; 34(2): 265-267.

Candy JM, Klinowski J, Perry RH, et al.: Aluminosilicates and senile plaque formation in Alzheimer’s disease. Lancet. 1986; 327(8477): 354-356.

Rees S, Cragg B: Is silica involved in neuritic (senile) plaque formation? Acta Neuropathol. 1983; 59(1): 31-40.

Tokutake S, Nagase H, Morisaki S, et al.: Aluminium detected in senile plaques and neurofibrillary tangles is contained in lipofuscin granules with silicon, probably as aluminosilicate. Neurosci Lett 1995; 185(2): 99-102.

Abeliovich A: Parkinson’s disease: Mitochondrial damage control. Nature. 2010; 463: 744-745.

Garruto RM, Swyt C, Yanagihara R, et al.: Intraneuronal colocalization of silicon with calcium and aluminum in amyotrophic lateral sclerosis and parkinsonism with dementia of Guam. N Engl J Med. 1986; 315(11): 711-712.

OEHHA: Toxicity data review: Decamethylcyclopentasiloxanes (D5), 2007. Available at review.pdf.

Malik VS, Popkin BM, Bray GA, et al.: Sugar-sweetened beverages, obesity, type 2 diabetes mellitus, and cardiovascular disease risk. Circulation. 2010; 121(11): 1356-1364.

Schwyzer RU: Multiple sclerosis: Prevention of serious illness—Vision of a desired future for newly ascertained patients. Med Hypotheses. 1992; 37(2): 115-118.

Buchter B, Dunkel M, Li J: Multiple sclerosis: A disease of affluence? Neuroepidemiology. 2012; 39: 51-56.

Tacke R: Milestones in the biochemistry of silicon: From basic research to biotechnological applications. Angew Chem Int Ed. 1999; 18(20): 3015-3018.

Buchter B, Dunkel M, Li J: Hypothesis: Everyday products induce multiple sclerosis. Med Hypotheses. 2011; 77(3): 466-467.

Sanz J, Serratosa JM: Silicon-29 and aluminum-27 high-resolution MAS-NMR spectra of phyllosilicates. J Am Chem Soc. 1984; 106(17): 4790-4793.



  • There are currently no refbacks.