The Cause

Volatile Methyl Siloxanes(VMS) are a class of chemicals with an increasing range of applications.

They are widely used in personal care products such as deodorants, tooth-pastes, skin care preparations, hair conditioners and as carriers in anti-perspirents. They are also used as effective cleaning agents of electronic circuitry.

Recently legislation has encouraged the dry cleaning industry to change from using chlorofluoro solvents to more environmentally friendly products, such as Siloxanes.

The waste from these industries are frequently disposed of in landfill sites. As organic matter decomposes it produces methane and carbon dioxide. The Siloxanes blend with this and contaminate the gas which is used to fuel engines that produce electricity.

Sewage treatment works acquire Siloxanes via industrial and domestic discharges. This is often supplemented by road tankers adding waste directly into the treatment process.

The contamination is similar to that experienced on landfill sites, with the resultant gas used to fuel engines.

The gas produced by these sites is frequently contaminated by Siloxanes particularly the cyclic D3, D4, D5 and the linear L2 all of which will decompose into silicon dioxide during the combustion process.