Reducing risk to building occupants and workers with air filtration devices

A proper air filtration setup will help to reduce the exposure of occupants and technicians to potentially dangerous materials, writes Cleaning Systems’ Paul Pritchard.

Air filtration devices (AFDs), more commonly known as ‘air scrubbers’ with HEPA filtration, are increasingly important in restoration. They have become the standard of care on most flood remediation or decontamination insurance claims in NZ.

AFDs should always be used when drying a structure with a known contaminant, and are also recommended when wall cavities, flooring surfaces or sub-surfaces are known to carry a high degree of organic debris, soils, allergens or other undesirable particulates.


Proper air filtration is important when building occupants have significant risk to exposure to particulates, specifically the very young, the elderly, and those who have respiratory problems or a compromised immune system.

Whenever airmover’s are used on any flood restoration job for drying, the amount of particulates in the restoration space dramatically increases likely causing risk to both workers and occupants or at the very least creating unpleasant malodours.
AFDs work by drawing the contaminated air through several stages of special filters, arranged in order from coarsest to finest filtration.

HEPA stands for High Efficiency Particulate Air Filtration. When used in-conjunction with airmovers, which can also have HEPA filters attached, a higher level of safety can be achieved.

Ask yourself: how often does at least one of the following conditions or tasks exist on a restoration job?

  • Contamination (sewerage, mould, or asbestos)
  • Drying carpet or carpet and underlay in place or “floating” carpet
  • Structural cavity drying
  • Customers who request air filtration
  • Customers who are concerned about allergies
  • Immuno-compromised individuals or other at-risk occupants.

The answer is of course every job has at least one of these conditions. This is why controlling dust, soot, and airborne bacterial contamination with air scrubbers or AFDs is essential and expected by insurance companies using preferred suppliers in NZ.

The Environmental Protection Agency (EPA)1 and American Lung Association2 have both published articles listing pollutants of concern. These pollutants can be classified into two types: particulate and gaseous.

The presence of airborne substances, whether non-visible respirable particles or the more visible larger particles, should always be assumed.

A proper air filtration setup will help to reduce the exposure of occupants and technicians to these potentially dangerous materials, and help to ensure that the indoor environment has truly been restored to its pre-loss condition.

Learn more about indoor air quality at EPA’s website

  1. “The Inside Story: A Guide to Indoor Air Quality,” EPA Document #402-K-93-007, 19 June 2003 Accessed April 16, 2019. 
  2. American Lung Association, “Indoor Air Pollutants and Health,” Accessed April 16, 2019.

*This article first appeared in the August issue of INCLEAN NZ

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