Sampling for VOCs should only be done after source elimination has been considered as a first step. If this is not possible, or too expensive, sampling could then be considered. The source-pathway-receptor relationship will have characteristics that will influence the sampling method and duration. Table 2-5 shows how VOC sampling can be tailored to suit various complaint patterns.
If the timing of a source is well known it may be used to define the source-pathway-receptor relationship and possibly eliminate or reduce the amount of VOC sampling required. For example, if odour or health complaints can be correlated with building conditions, occupant/neighboring activities, weather, or ventilation system status, then it may be possible to determine the source or pathway, and mitigate the problem without sampling or to adjust the sampling program.
The duration of sampling should provide data that it is representative and meaningful. How the data will be interpreted should be considered. Timing factors may also be defined by legislation such as determining short-term exposure or time weighted average exposure for workers. Where timing is not defined by legislation, occupants should be interviewed or asked to complete a questionnaire to gain an understanding of when exposure may be occurring. It is important to note that complainants may not always be objective when providing information.
To learn more about VOC sampling methods go to our downloadable module: http://iaqforum.ca/wp-content/uploads/2012/11/Mod2_VOC.pdf