Mould Testing: An imperfect science

Parents or staff frequently call for “testing” of a building.

CAUTION: Testing for mould or other indoor air factors is not always useful.

If an air quality test did not find mould this is not a conclusive guarantee that mould is not the problem. Common mould tests measure only live spores. If the colony is in a dormant part of the life cycle, live spores will not be in production, and not be found. If the moisture levels are down, or if air circulation is up, or any of several other factors are present or absent, the tests may not find mould even though mould contamination may still be present. This is an oversimplification, but a very important point. Air quality tests for moulds, VOCs, CO2, and much more may not be reliable for many reasons. Professionals in building environments rely on much more than testing to evaluate what is usually a complex situation. It tends to be better to ask for evaluation by building environment specialists rather than just asking for testing. These experts will know whether testing is likely to be helpful, and what action is needed.

Mould is often involved, but there are many other causes and contributing factors to poor IAQ. Skilled building evaluators know that testing is far from infallible and often is unnecessary. Tests are only one of the tools used to determine problems with a building. In fact, testing can let everyone down.

Evaluation is more effective.

See Air Quality Testing and Other Challenges to Building Evaluations on CASLE’s website for more information on building evaluations and tips on how to choose evaluators.

Canadians for A Safe Learning Environment