The combination of element-specific investigation by low temp. gas chromatog. coupled online with inductively coupled plasma optical emission spectroscopy (LT-GC/ICP-OES) and gas chromatog. using mass spectrometry detection (GC-MS), as an addnl. anal. technique for mol. identification, was employed for the detn. of volatile organosilicon species. Gaseous and liq. samples from waste deposit sites, waste composting tanks, and sewage-disposal plants were investigated. It was frequently possible to identify the labile silanol compd. trimethylsilanol as a dominant Si species in waste disposal and waste composting gases. Trimethylsilanol is a volatile product of the degrdn. of organosilicon materials under special environmental conditions.