There is often no single factor that determines the quality of indoor air in an office, retail, or enclosed space. The Indoor Air Quality (IAQ) of a building is a complexity of factors that influence the link to human health effects.
Concentrations of indoor air pollutants are influenced by changes in activities both within and outside the buildings, cleaning, heating and renovation regimes, the degree of ventilation, and the presence of products that are hazardous (including asbestos) or emit volatile organic compounds.
Increasingly, as dwellings have become better sealed from the external environment, pollutants being released from indoor sources are being found at higher concentrations such as fungi, microbial contamination, house dust mites, particulates and air toxics such as formaldehyde.
The Purple Tick selects approved laboratories such as CETEC with significant IAQ assessment experience (ie air quality monitoring) and which purple tick air quality a strong focus on the quantitative elements of IAQ.
The Purple Tick and CETEC adopt a disciplined sampling methodology. This may include airborne sampling and swabbing of representative affected areas. In many instances, speciation may be necessary as some species are more hazardous to human health than others.
Quantitative measures can involve monitoring the following:
Temperature and humidity
Measurement of building ventilation rates (carbon dioxide) and the effectiveness of the ventilation system
The concentration of selected indoor air pollutants, such as VOCs, carbon monoxide and formaldehyde
Air particulates
Airborne microbials
Radiation
