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Air Samples

Is Air Sampling the correct test for your situation?

There are many tests available to test for mould. Unfortunately for the customer, most inspection companies rely solely on one test – an Air Sample – to determine if there is a problem in your home.

While the air sample is useful in some instances, if you need to know where the mould is growing. If want to have the problem fixed and the mould removed, then you may want to consider hiring a company that used other methods of testing to actually find the mould.

An air sample cannot tell you where the mould is or which surfaces require cleaning. Nor can the air sample tell you about historical problems.
And yes, while an air sample is often used as a prescreening method, further investigations will need to be conducted to determine where the mould is and how extensive the problem is.

If the mould inspection company that you are hiring is planning to only provide you with one air sample, then the information gained from this may not be adequate to quantify the extent of the problem.

If I can see mould, then why do I need a mould inspection and mould testing?

Some interesting facts about Indoor Air Samples:

  • Air sampling is a testing method designed for the rapid collection of airborne aerosols. These include mould spores, pollen, skin fragments, asbestos, insect parts, drywall dust, fibreglass.
  • Air sample results can vary dramatically depending on time and location and many samples are needed to compensate for this variability.
  • Air sampling should not be done on rainy days.
  • An air samples can often produce “false positives” or “false negatives”
  • Some moulds like Stachybotrys chartarum (Black toxic Mould) does not aerosolize well and therefore often does not show up on an air sample.
  • An air sample can be influence by vacuuming in the room up to an hour before the sample is taken.
  • An air sample can be influenced by opening and closing doors or windows.
  • Very few companies take sufficient samples: at minimum you require a control sample, a sample from the complaint area and a non-complaint area or one sample per 1000 sq ft./ per level.
  • Some unscrupulous companies will offer a ‘Fogging” of the room prior to air sampling, thus guaranteeing a “pass” on the air sample.
  • There are no set standards or exposure limits for determining if an air sample is a pass or fail.
  • Health Canada recommends that air sampling alone should not be used to make a determination concerning the heath of the occupants.
  • In every case, if high levels of spores are found on an air sample, you will still need the information about where the mould is, how extensive and information on what protocols should be used to have it removed.

Talk to your inspection company to determine if they can provide you with the correct testing for your particular problem and situation. This is one case where one size does not fit all.

Mould Inspections – Other ways to sample the Air Laser Particulate Counters

In microbial remediation projects, all parties may benefit when using the laser particle counter as an indicator that the aerosolized debris has been adequately purged prior to actually submitting post-remediation verification sampling for laboratory analysis.

This provides a real-time indicator that all aerosolized microbial and non-microbial debris were adequately purged before conducting the final cleaning regimen and third-party validation.

Laser particle counters can also help determine the collection efficiency of HEPA filters, thus eliminating the possibility of disposing filters before their full use.