In part 1 of our guide to UK building air quality, we discussed the importance of assessing external quality (step 1) and setting benchmarks (step 2) as a prerequisite to achieving optimal levels of building air quality. In part 2, we will expand on this approach outlining how businesses can shape their approach to testing (step 3), and risk management (step 4) to control the air quality within their buildings, regardless of scale and purpose.
Step 3) Testing indoor air quality
One of the behaviours which separate businesses with higher levels of internal quality with those with low air quality is the extent to which they have an effective testing protocol in place. In step 2, we stressed the importance of setting benchmarks for internal air quality and defining these in an Internal Air Quality Plan (IAQ Plan). Step 3 is about ensuring the correct type and standard of testing is being undertaken, with the aim of ensuring that all internal air is being filtered effectively.
Indoor air quality may be impaired for several reasons, including inadequate maintenance of Air Handling Units (AHUs), incorrect filters, or systems which are not fit for purpose. With poorly maintained and managed systems, air leaks can occur due to defective seals on AHUs, leading to a corresponding reduction in air quality and hygiene due to the inability to filter out microorganisms which are harmful to human health.
It is now possible to test for a wide range of pollutants and toxins, including carbon monoxide, particulate matter, VOCs, humidity, formaldehyde, and radon by using measurement devices and sensors. Such technology, whether used by internal staff or an external testing provider, can ensure that testing is an ongoing process, and will flag when air quality falls outside of the tolerances set in step 2.
It is also recommended that testing of air filters ensures that performance of AHUs conforms to ISO 16890 (the international standard for air filters for general ventilation). ISO 16890 states:
“The effects of particulate matter (PM) on human health have been extensively studied in the past decades. The results are that fine dust can be a serious health hazard, contributing to or even causing respiratory and cardiovascular diseases. Different classes of particulate matter can be defined according to the particle size range. The most important ones are PM10, PM2,5 and PM1”.
In some cases, existing AHUs may not conform to the ISO 16890, either because a higher standard of filter is needed, or because the unit needs updating to a newer technology capable of meeting the standard.
Step 4) Effective risk management
So far, we have assessed external air quality, set benchmarks for clean air within our buildings (and documented this in an IAQ plan), and put in place effective air quality testing. At this stage, any specific indoor air quality risks can be identified and mitigated.
This is especially pressing in the current context of COVID-19, as it is now well established that impaired immunity can pose an additional risk factor. In addition, there is a growing body of evidence that ultrafine particles (PM1) accumulate in the body, leading to long-term damage to the circulatory system, dementia, emphysema, and other serious conditions. PM1 particles are in the region of one micrometre (one-millionth of a meter) in diameter, and include diesel fumes, dust, bacteria, and even viruses.
The testing process identified in step 3 will enable your organisation to identify any harmful components in the air within your buildings, and put in place a plan to remove them, including by selecting and installing air filters designed for the specific risks you have identified. Air filters can be chosen based on their ability to trap ultrafine particles (e.g. HEPA Class H13 filters) and contaminants found during testing. If your building is in an area with high outside pollution, as may be the case in a city, a higher specification of AHU and/or filter may be required. In addition, where greater levels of air filtration are needed, air cleaning technology can be fitted retrospectively to many buildings, further boosting indoor air quality.
Optimal indoor air quality requires an ongoing commitment to the measurement and testing of air quality, and identifying and mitigating specific risks. An investment in air quality measurement sensors and equipment, and air filtration and cleaning technology will pay dividends for the health and wellbeing of individuals within your care; whether they are employees, contractors, members of the public, customers, and visitors. Adopting a ‘one size fits all’ approach to air filtration is neither recommended nor effective. Air filtration technology has now advanced to the point where even the smallest particles can be removed from circulating air and can be tailored to the specific contaminants in your building.