1.1 This test method covers the sampling/analysis of respirable suspended particles (RSP) and the estimation of the RSP fraction attributable to environmental tobacco smoke (ETS). The test method is based on collection of total RSP on a membrane filter, extraction of the filter in methanol , and determination of solanesol, a C45 isoprenoid alcohol, by high performance liquid chromatography (HPLC) with ultraviolet (UV) detection.