Post-Abatement Clearance & Air Testing

For a Type 3 asbestos job, Ontario's regulation requires a clearance air test before the enclosure comes down. O. Reg. 278/05, section 18, says the test is conducted by a competent worker once the enclosure is dry, and that with the PCM method the area passes only if every air sample "has a concentration of fibres that does not exceed 0.01 fibres per cubic centimetres of air". At least 2,400 litres of air are drawn per filter. A TEM method is also allowed, where the inside average is compared with the outside. Results are posted within 24 hours and the owner keeps a copy for at least one year.

The regulation prescribes a clearance air test for Type 3 only. We found no clearance test in the Type 1 and Type 2 sections, so if you want one after a smaller job, ask for it in the quote.

After mould work there is no Ontario clearance standard. A post-remediation check should confirm the mouldy material is gone, the area is clean and dry, and the moisture source is fixed.

Published Ontario prices for an air clearance test run about $300 to $800. Ask who takes the samples, which method they use, and whether the written results come to you as well as to the contractor.