Quick answer
Four-stage clearance is the HSG248 process for signing off after licensed asbestos removal: (1) preliminary check of the work site, (2) thorough visual inspection, (3) air monitoring and clearance indicator (<0.01 f/ml), (4) final assessment post-dismantling of the enclosure. Only then can a Certificate of Reoccupation be issued.
The four stages
The sequence, per HSG248:
- Stage 1 — preliminary check of site condition and job completeness
- Stage 2 — thorough visual inspection of the enclosure interior
- Stage 3 — air monitoring inside the enclosure (result <0.01 f/ml)
- Stage 4 — final visual assessment after enclosure dismantling
Who does it
An independent UKAS-accredited analyst — never the removal contractor themselves. Independence is what makes the certificate legally meaningful.
Frequently asked questions
Common questions
Can I skip the clearance?+
No. Reoccupation without a valid clearance certificate is a breach of CAR 2012.
What if stage 3 fails?+
The contractor must clean and retest. Repeated failures escalate to remedial cleaning or SEM.
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