This standard is intended as an aid to planning measurements for PCBs, PCDDs, PCDFs and PAHs in indoor air. In the case of indoor air measurements, the careful planning of sampling and the entire measurement strategy are of particular significance since the result of the measurement may have far-reaching consequences, for example, with regard to the need for remedial action or the success of such an action. An inappropriate measurement strategy may contribute to the complete uncertainty of the measurement result in a larger extent than the measurement procedure itself.