There are few more important jobs than ensuring the safety of the air we all breathe. And whether they are focusing on ambient air, stationary air source emissions, or indoor/workplace air, laboratories need to know they can rely on their results. An extremely important, yet often overlooked, element of this is filter selection.
With its sprawling regulatory landscape and multitude of settings, targets, and processes, air monitoring may be a complex arena, but it is also one that demands precision – right down to the seemingly smallest detail.
As anyone working in this sector knows, air quality monitoring is a matter of public health. There is no room for error because mistakes can seriously harm human and business health alike.
Ambient air is the air outside of buildings accessible to the public, such as that in city centres. It can contain harmful components, including various size fractions of particulate matter, and airborne chemicals such as organics, heavy metals, and gases such as sulphur dioxide (SO2), carbon monoxide (CO), and nitrogen dioxide (NO2).
Stationary air source emissions, such as those emitting from factories, refineries, boilers, or power plants may contain particulate emissions, heavy metals, and gases including nitrogen oxides (NOx) or volatile organic compounds (VOCs).
And indoor workplace air, depending on the nature of the business, may contain substances such as asbestos fibres, welding fumes, or silica dust, for example.
Organisations, then, have a moral responsibility – not to mention a regulatory duty – to ensure their processes can reliably detect toxicity in a timely manner. It is, however, no mean feat.
Laboratories are tasked with testing for a complex web of setting-specific targets, whether they be physical, chemical, or biological, at thresholds that can vary widely depending on the air-type classification. In addition, monitoring requirements are driven by regulations, which themselves vary by region, setting, and target.
Filtration matters
A common thread throughout is filtration. This seemingly simple step is an integral part of many air quality monitoring processes, and filter characteristics can have a considerable bearing on the reliability of the tests themselves.
Inadequate retention efficiency or flow characteristics, for example, can allow target particles to evade collection.
Filters that are susceptible to mass loss or are too fragile to withstand clamping procedures can skew the relationship between baseline and final results.
It can all add up to a lack of confidence in data, threats to regulatory compliance, and the need for avoidable, costly, productivity-draining re-tests. So how can laboratories make the right choice, first time?
Selection considerations
While a number of standard methodologies stipulate a filter, this is far from the norm. Many contain just generic descriptions of the necessary filter, and others only stipulate
specific performance criteria, such as retention efficiency
In the absence of regulatory guidance, technicians are left to make the appropriate selection themselves. Considerations vary according to the test at hand and tend to in include:
- will the filter collect the target particle?
- will the filter contribute to background target levels?
- will the filter lose mass during the process?
- is the filter difficult to handle?
When collecting particulate matter for chemical analysis, for example, technicians need filters with the appropriate retention efficiency, made from materials that will not contribute to background levels of the target chemical.
During manual sample collection prior to physical analysis, the filter should have a flow rate and loading capacity necessary to collect the full sample without blocking. And, when working in harsh sampling environments, such as high temperatures, the filter needs to be able to withstand the conditions.
Robust. Reproducible. Reliable
Filtration may seem like a small, simple piece in the complicated air monitoring jigsaw, but this common misconception could not be further from the truth.
Using the right product for the task at hand is essential for the generation of quality, reproducible results that laboratories can rely on. It gives organisations confidence
in the safety of their air and the accuracy of their processes.
And importantly, it helps avoid the need for unnecessary, costly, productivity-draining re-tests.
Find out how to match the right filter to your ambient air, stationary air source emissions, and indoor/workplace air chemical and physical analyses with our new eBook. Click here to download your free copy of Filter selection: A simple path to increased air monitoring efficiency