Class A vs Class B Asbestos Removal: The Equipment You're Required to Have
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A Class B licence and a Class A licence are not the same business. The paperwork is different, the training is different, and the gear on the truck is different by an order of magnitude.
This is the equipment side of it, written for someone deciding whether to stay Class B or step up.
What's the difference between a Class A and a Class B asbestos removal licence?
It comes down to friable versus non-friable.
Non-friable asbestos is bonded into a matrix — fibro sheet, vinyl tiles, cement pipe, roof sheeting. Intact, it holds its fibres.
Friable asbestos can be crumbled, pulverised or reduced to powder by hand pressure when dry — pipe lagging, sprayed limpet, millboard, and any asbestos-contaminated dust or debris (ACD).
Under the NSW Work Health and Safety Regulation 2017:
- Clause 458 puts the duty on a person conducting a business or undertaking to ensure the asbestos removal work is carried out by a licensed asbestos removalist.
- Clause 485 sets the work that requires a Class A licence — friable asbestos, and asbestos-contaminated dust or debris.
- Clause 487 sets the work that requires a Class B licence — more than 10 square metres of non-friable asbestos or ACM.
- Removing 10 m² or less of non-friable asbestos doesn't need a licence, but every other duty still applies.
A Class A licence holder can do Class B work. The reverse is never true.
Clause numbers here are NSW; other states adopt the model WHS Regulation with equivalent provisions — check your state's version.
What equipment does each class actually require?
| Class B (non-friable, over 10 m²) | Class A (friable and ACD) | |
|---|---|---|
| H-Class vacuum (AS/NZS 60335.2.69) | Required | Required |
| Sealed enclosure | Not usually | Required |
| Negative pressure unit | Not usually | Required |
| Air changes in the enclosure | n/a | at least 4 per hour |
| Decontamination unit | Basic — bucket, wash, PPE bagging | Three-stage decon unit, attached to the enclosure |
| Respiratory protection | Selected by risk assessment under AS/NZS 1715 — commonly P2 half-face for Class B, PAPR or supplied-air on friable work. | |
| Air monitoring | Not mandatory | Mandatory (cl 475), by an independent licensed asbestos assessor |
| Clearance inspection | Independent competent person (cl 473) | Independent licensed asbestos assessor (cl 473) |
| Clearance certificate | Required before re-occupation (cl 474) | Required before re-occupation (cl 474) |
| Notification to the regulator | Required | Required |
| Worker training | CPCCDE3014 Remove non-friable asbestos | CPCCDE3015 Remove friable asbestos |
The short version: Class B is a vacuum, PPE, wetting down and controlled disposal. Class A is all of that plus a sealed, ventilated, monitored box that you build and then prove is working.
Why does Class A work need a negative pressure unit?
Because a sealed enclosure on its own doesn't stay sealed. Someone leans on it, a corner tears, a door opens. If the inside of the enclosure is at the same pressure as the corridor, the air moves whichever way it likes.
A negative pressure unit fixes the direction of travel. It draws air out of the enclosure through a HEPA filter and exhausts it clean, so the enclosure sits below the pressure of the surrounding area. Every leak becomes an inward leak. Clean air goes in, nothing contaminated comes out.
Two numbers do the work.
Air changes per hour. Australian practice, following the Code of Practice, is at least four air changes per hour in the work enclosure. Take the enclosure volume in cubic metres, multiply by four, and that's your minimum extraction rate in m³/h. Then add margin, because filters load up and airflow drops as the job goes on.
Negative pressure differential. The enclosure must be held measurably below the pressure of the surrounding area, and you have to be able to show it. Verify it with a manometer and smoke test the enclosure before work starts — a reading you can point to beats an assumption every time.
Sizing an example. A 5 m x 4 m room at 2.4 m high is 48 m³. Four air changes gives 192 m³/h as an absolute floor. A Smart Dec S55 SE ($2,885.85) moves 900 m³/h with the filter fitted at 230V, weighs 21.5 kg and runs an H13/H14 filter to EN 1822 — so it covers that room with a lot of headroom, and it's light enough for one person to carry up a ladder. For a large ceiling void or a multi-room strip-out, a Green Dec G 200 (from $7,713.00) or a Green Dec G 300 (from $9,975.00) is the sensible starting point.
Position the NPU at the opposite end of the enclosure to the decontamination unit. That way the only significant path for makeup air is in through the decon unit, and the airflow across the work area is smooth rather than swirling.
Smoke test the enclosure before you start removal, every time. It's the only cheap way to find the leak you built in.
What does a Class A decontamination unit have to do?
Three stages, in order, attached directly to the enclosure: dirty end, shower, clean end.
The worker leaves the work area into the dirty room, removes and bags the contaminated coveralls, showers with the respirator still on, then removes the respirator and dresses in the clean room. The stages are physically separated so contaminated air and clean clothing never share a space.
That's why a Class A decon unit is a real piece of plant and not a shower tent. It needs water supply, wastewater filtration so asbestos fibres don't go to sewer, and its own airflow relationship with the enclosure.
Deconsafe's range runs from a SMART Line 1000 three-chamber shower ($8,601.89) and the SMART+ 1000 ($10,073.76) for standard site work, up to the ECOLINE 1000 ($17,016.16), and then to trailer-mounted units like the Mobile Decon Unit E4000 ($92,357.30) for large or remote projects. There's also a DeconSafe Disposable Decontamination Unit ($500.00) for smaller controlled jobs — call us to confirm it suits your job class.
What air monitoring is required, and who has to do it?
For Class A work, clause 475 of the NSW WHS Regulation 2017 requires air monitoring of the asbestos removal area, carried out by an independent licensed asbestos assessor. Independent means not you and not your employee.
The numbers used in practice:
- Below 0.01 fibres/mL — controls are working, keep going.
- 0.01 to 0.02 fibres/mL — stop and review the controls before continuing.
- Above 0.02 fibres/mL — stop work, find the cause, fix it. Clause 476 deals with action required when the respirable fibre level is too high.
Samples must be analysed by a NATA-accredited laboratory using the membrane filter method in Safe Work Australia's guidance note.
Clearance is separate again. Under clause 473 a clearance inspection is required after the work, and under clause 474 a clearance certificate must be issued before the area is re-occupied. For Class A work, the assessor must be an independent licensed asbestos assessor; for other licensed work, an independent competent person.
Is stepping up from Class B to Class A worth it?
Be honest about the capital. A serviceable Class A setup — enclosure materials, NPU, three-stage decon unit, H-Class vacuums, PAPR respirators, air monitoring budget — is a five-figure commitment before you win the first job, and the decon unit is usually the biggest single line.
It's worth it if you're regularly turning down friable work, or subcontracting it and watching the margin walk out the door. It isn't worth it to occasionally chase one job a year. Hire is the middle path — most NPUs and decon units on our range are available for hire as well as sale, which lets you price a Class A job properly before you own the equipment.
FAQ
Do I need a negative pressure unit for Class B non-friable removal?
Usually not. Full enclosure with negative pressure is a Class A control for friable work. Class B non-friable removal relies on wetting down, controlled work methods, H-Class vacuuming and controlled disposal. A risk assessment can still call for an enclosure on a Class B job.
Can a Class B licence holder remove asbestos-contaminated dust?
No. Asbestos-contaminated dust or debris is Class A work under clause 485, regardless of what it came off. If a non-friable job has generated ACD, the cleanup crosses into Class A territory.
Is air monitoring required for Class B work?
Not as a standing requirement — clause 475 attaches air monitoring to Class A removal. A clearance inspection and a clearance certificate are still required, and a risk assessment or the client may call for monitoring anyway.
How many air changes per hour does an asbestos enclosure need?
At least four per hour, per the Code of Practice. Size the NPU on enclosure volume x 4 as a minimum, then add capacity for filter loading. Undersizing is the most common mistake we see.
Do I need an H-Class vacuum for both Class A and Class B?
Yes. The vacuum standard — Class H to AS/NZS 60335.2.69 — doesn't change with licence class. A Numatic HZ370 ($1,870.00) covers a Class B crew; Class A work needs more capacity and more machines.
Who can issue the clearance certificate?
For Class A work, an independent licensed asbestos assessor. For other licensed removal work, an independent competent person. Either way, the certificate must be issued before anyone re-occupies the area (cl 473 and 474).
Deconsafe Solutions supplies negative pressure units, decontamination units, H-Class vacuums and consumables to licensed asbestos removalists across Australia. We're the only Deconta dealer in the country. Most NPUs and decon units are available for hire as well as purchase. Prices above are current at time of writing.