ISO 16000-12:2008 specifies the planning of measurements for polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) also known as polychlorinated oxanthrenes, polychlorinated dibenzofurans (PCDFs) and polycyclic aromatic hydrocarbons (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, e.g. with respect to the need for remedial action or the success of such an action. An inappropriate measurement strategy may contribute more overall uncertainty to the measurement result than the measurement procedure itself.