The present invention provides a filtering system for a semiconductor processing tool. In one embodiment, the filtering system is associated with the semiconductor processing tool. A system of the invention comprises a first and second filter layer in fluid communication with a gas flow path. The flow path is a gas stream comprising volatile silica containing compounds such as hexamethyldisiloxane and trimethylsilanol. The gas flow path passes through the first and second filter layer to fluidly communicate with the semiconductor processing tool. Preferably, the first filter layer of the filtering system is upstream along the gas flow path from the second filter layer. The medias of the first and second filter layers are selected and arranged based on given contaminant concentrations. The invention also provides a method for filtering gas containing hexamethyldisiloxane and trimethylsilanol in communication with a semiconductor processing tool, which employs a system comprising a first and second filter layer.