The document describes methods for measuring various indoor air pollutants. However, other measurement methods which were primarily developed for the field of ambient air pollution are also suitable and have been proven for indoor air measurements. Part 3 deals with determining pentaclorophenol (PCP) and γ-hexachlorcyclohexane (γ-HCH, lindane, see annex A for chemical structures) and describes the GC/MS method. The method is designed for measuring in the air of living rooms and indoor environment for a sampling period of 0,5 to 8 hours. With a sampling time of one hour, concentrations in the range from approximately 0,02 ?/m3 to 1 ?/m3 (=20 ng/m3 to 1000 ng/m3) can be determined.