Air monitoring and clearance: how a job is signed off
The job is not finished when the truck leaves. It is finished when somebody independent puts in writing that the area is fit to use again.
('Two steps sit at the end of an asbestos removal, and they are the two most often skipped on a cheap quote: air monitoring and a clearance certificate.
Air monitoring
Air monitoring measures the concentration of respirable fibres in the air. Air is drawn through a filter at a controlled rate, and the fibres collected are counted under a microscope. It can be done before work starts to establish a background level, during the work to check the controls are holding, and at the end to confirm the area is below the clearance criterion.
For friable (Class A) work it is mandatory, and it must be carried out by a licensed asbestos assessor independent of the removalist. That independence is the point of the whole arrangement. For bonded work it is not always required, but it is worth having when the job was indoors, large, or close to neighbours.
The clearance certificate
The clearance is what allows people back in. It records that the area has been visually inspected and found free of visible asbestos residue and dust, and — where monitoring applies — that measured fibre levels meet the clearance criterion.
The visual half matters more than people assume. Most failures are not exotic: debris left in a gutter, fragments in a garden bed, dust in a roof space, a bag left behind the shed. A proper clearance inspection is what catches those before the barriers come down.
Why incomplete clean-up is the real risk
If a household ends up with a contamination problem after a removal, the cause is usually not the removal itself. It is the clean-up. The sheets came off correctly and then the site was left with material in the places nobody looks: gutters, downpipes, under the eaves line, in the soil, in the ceiling space, behind the shed.
This is why “does the quote include decontamination and clearance” is a better question than “how much”.
Keep the certificate
The clearance certificate is a document with a long life. It matters when you sell the house, when a tradesperson asks what has been done in a space, when an insurer or a strata committee asks, and when the next owner wants to know why part of the building is recorded the way it is. File it with the survey and any laboratory reports.
When can you move back in?
When the clearance says so, in writing — not when the work looks finished, not when the skip is collected, and not because somebody says it is fine. On a friable job that means after the assessor has both inspected and monitored. This is the one part of the process where waiting an extra day costs nothing and moving early can cost a great deal.
', 0)Frequently asked questions
Is air monitoring always required?
For friable (Class A) work it is mandatory, carried out by a licensed asbestos assessor independent of the removalist. For bonded work it is not always required, but it is worth having when the job was indoors, large or close to neighbours.
Why must the assessor be independent?
Because the party doing the checking cannot be the party being checked. On Class A work the law requires the assessor doing monitoring and clearance to be independent of the removalist.
What does a clearance certificate actually say?
That the area has been visually inspected and found free of visible asbestos residue and dust, and — where monitoring applies — that measured fibre levels meet the clearance criterion. It is what allows reoccupation.
What usually goes wrong after a removal?
Incomplete clean-up rather than the removal itself: debris in gutters and downpipes, fragments in garden beds, dust in the roof space, material left in the soil. A proper clearance inspection is what catches those.
Sources
What this page explains is based on these official sources. If you check one and it does not match what you read here, send it to us and the article gets corrected.
- SafeWork NSW. Asbestos — hazards A–Z
- WorkSafe Victoria. Asbestos — duties, licensing and safe removal