Parameter Objective of measurement Average concentration Maximum concentration Ambient temperature normal conditions normal conditions Relative humidity normal conditions normal conditions Ventilation status before sampling during sampling normal normal no ventilation: doors and windows closed no ventilation: doors and windows closed Occupancy normal activity maximum occupancy Source status normal use heavy usea Sampling location centre of room at 1-2 m height close to activity Time of sampling anytime during activity Duration of sampling 5-14 days 30-60 min Minimum number of samplesb for orientation for control of compliance 1 2 1 3

Table 2: Recommended conditions for VOCs sampling in the air of public buildings and private homes (adopted and modified from ECA report no 6, 1989 [22]). a. Attention has to be paid to instructions and warnings for the use of products to avoid potential health damage. In case of combustion sources, temperature and humidity will rise in such experiments. Beware also of rising carbon monoxide concentrations. b. Duplicates are desirable.