26/11/2025
Understanding Asbestos: What’s the Difference Between Class A and Class B Materials?
When we talk about asbestos in New Zealand, you’ll often hear the terms Class A and Class B.�These come directly from the Health and Safety at Work (Asbestos) Regulations 2016 and describe the type of asbestos-containing material (ACM)
Here’s what they mean in everyday language:
🔶 CLASS A ASBESTOS (Friable Asbestos)
Official definition:�Asbestos that can be crumbled, pulverised, or reduced to powder by hand pressure when dry.�(Friable = easily becomes airborne)
Examples include:
Sprayed-on insulation
Pipe/boiler lagging
Old fireproofing materials
Loose-fill asbestos
Weak, deteriorated materials that are breaking down.
Why it’s high risk:�Friable asbestos releases fibres easily. Even small disturbance can make fibres airborne, which is when exposure risk increases.
🔷 CLASS B ASBESTOS (Non-Friable or Bonded Asbestos)
Official definition:�Asbestos-containing material where the fibres are strongly bound within a solid matrix.�(Non-friable = stable unless cut, drilled, broken, or weathered)
Common examples in NZ buildings:
Asbestos-cement sheets (AC sheets, “fibro”)
Asbestos cement roofing
Vinyl floor tiles with asbestos backing
Textured coatings (some types)
Old pipes, flues, gaskets, fencing panels
Risk level:�Lower than friable when intact.�BUT: if damaged, aged, drilled, sanded, or weathered, it can become friable, increasing the risk.
🧪 How Do You Know Which One You’re Dealing With?
You cannot confirm whether a material contains asbestos simply by looking at it.
In NZ, this can only be confirmed by:
-a licensed asbestos assessor taking a proper sample and
-analysis by an IANZ-accredited laboratory
These two steps together give you a correct, legally recognised answer.
📍 Where Are These Found in NZ?
If your home, school, or workplace was built before 2000, asbestos-containing materials may be present.�
Common places include:
Ceilings, walls, bathrooms, floor tiles
Roofs, cladding, soffits
Old heaters, flues, fireplaces
Adhesives, sealants, insulation products
🛑 Why This Matters
Understanding Class A vs Class B materials helps you:
-recognise which materials are higher risk
-know when to stop work immediately
-know when to call a professional
-keep children and staff safe in schools and ECEs
-respond safely during incidents like product recalls
👷 Need clarity or testing?
If you have a product or material you’re unsure about, a licensed asbestos assessor can safely take a sample and confirm exactly what you’re dealing with.