How Many Types of Asbestos Are There?

Asbestos is one of the most infamous materials in construction history. Once used in an unquantifiable number of construction materials that it’s almost hard to imagine, now it is recognised as one of the most harmful substances in any building, or any environment.

In the UK, asbestos use was banned in 1999, but millions of homes, schools, offices, and industrial sites still contain it. For anyone involved in building work, maintenance, demolition, or property management, understanding the different types of asbestos is essential for the safety of every resident or visitor. Cordtape Environmental have you covered.

The six types of asbestos

The six asbestos minerals are divided into two groups:

• Serpentine (curled fibers)
• Amphibole (straight, needle like fibers)

Each type has its own history, appearance, and hazards.

Chrysotile (serpentine)

Chrysotile fibers are long, silky, and curly, usually white to light grey in colour. They have a layered, flexible structure that makes them easier to spin and weave into fabrics. Chrysotile deposits were mined extensively in Canada, Russia, Zimbabwe, and Italy, with the Jeffrey Mine in Quebec being one of the largest asbestos mines in the world.

Despite its flexibility, chrysotile is still extremely hazardous when inhaled, and because it was used in such large volumes, it’s the most common asbestos type found in UK buildings today.

Chrysotile accounts for roughly 90% of historical UK asbestos use. Fibers can split into microscopic strands, making them easy to inhale.

Common Uses:

• Roofing materials and cement sheets
• Pipe and boiler insulation
• Fireproof spray coatings
• Textiles (fire blankets, gloves)
• Gaskets and brake linings

Actinolite (amphibole)

Actinolite is usually greenish in colour, with straight, sharp fibers that can range from silky to brittle. It’s most often found as a contaminant in other minerals rather than as a mined product. Deposits have been identified in Canada, Finland, and the USA.

Its heat resistance made it suitable for use in certain insulation and cement products, though it was never as widely adopted as chrysotile or amosite and is rarely found in UK buildings.

Common Uses:

• Insulation materials
• Cement
• Drywall compounds
• Sealants

Amosite (amphibole)

Amosite fibers are straight and brittle, typically brown or grey, and have a needle like shape. This asbestos type was mined mainly in the Transvaal region of South Africa. It’s known for its excellent heat resistance and tensile strength, which made it ideal for insulation boards and cement sheets. However, the sharp fibers can lodge deep in the lungs, posing a high mesothelioma risk.

This is the second most common asbestos type in the UK. Breaks easily into airborne fibers during maintenance or demolition.

Common Uses:

• Thermal insulation in pipes and boilers
• Ceiling tiles and acoustic panels
• Cement sheets
• Fireproof insulation boards

Anthophyllite (amphibole)

Anthophyllite fibers are grey, brown, or dull green, with a coarse texture. This asbestos type was mined in smaller quantities, mainly in Finland, Georgia (USA), and North Carolina. It’s rare in UK construction materials. Its resistance to heat and chemical attack meant it was occasionally used in cement and insulation products.

Common Uses:

• Some cement and insulation products
• Contaminated talc

Crocidolite (amphibole)

Crocidolite fibers are fine, sharp, and a striking blue grey colour. Mined mainly in South Africa, Bolivia, and Australia, crocidolite is the most hazardous asbestos type due to its extremely thin fibers, small enough to bypass the body’s natural respiratory defenses. It was widely used in high temperature environments, especially in shipbuilding, before its dangers became undeniable. Crocidolite has the highest rate of asbestos related disease among workers exposed to it.

Common Uses:

• High temperature insulation
• Spray on fireproofing
• Cement pipes and water supply systems
• Shipbuilding insulation

Tremolite (amphibole)

Tremolite fibers range from white to dark green, with a rough, splintery texture under magnification. It wasn’t mined commercially for direct use, but was a frequent contaminant in other minerals such as talc and vermiculite. Major deposits have been found in Italy, the USA, and Austria. Tremolite contamination was one reason for product recalls involving talcum powders and garden vermiculite.

This type of asbestos is dangerous even in trace amounts, as its fibers can cause long term lung damage.

Common Uses:

• Plasters and sealants
• Paints
• Asbestos insulation products

Friable vs non friable asbestos

Asbestos materials can be either friable or non friable. Friable means the asbestos can be crumbled into a fine powder whereas non friable means it cannot.

Because friable asbestos can become airborne as fibres, it is considered more of a health risk than non friable asbestos.