The Difference Between Class A and Class B Asbestos

Asbestos used to be one of the most popular components in building materials. Not only was it cheap and long-lasting, but it was also flame retardant. Up until the 1980s, asbestos was used in cement, insulation materials, roofing sheets, and spray-on fireproofing.

However, the health hazards of asbestos fibres were soon discovered. Some of these risks include asbestosis, resulting in permanent lung damage; cancer of the gastrointestinal tract, kidney, larynx, and/or oropharynx; lung cancer; mesothelioma, a rare kind of cancer in the chest and stomach lining; and scarring of the lungs.

Upon these discoveries, manufacturers eventually stopped using the material. As such, recent structures are essentially guaranteed to not have components that contain asbestos. On the other hand, homes and buildings constructed or renovated between 1950 and 2000 have a high likelihood of having asbestos or asbestos-containing materials (ACMs) in their components.

Asbestos regulations in New Zealand came into full effect on 4 April 2018. This is after a two-year window given to the industry to implement the Health and Safety (Asbestos) Regulations in 2016. Part of these regulations states that if you occupy or own a building with ACMs, you need to develop a management plan to minimise adverse effects. Moreover, it requires a licenced professional to have your building checked for asbestos before you can renovate.

Do note that there are two kinds of asbestos in construction: Class A and Class B. They are classified based on their level of risk. For example, there are some ACMs that won’t release fibres as long as they remain in good condition and remain undisturbed. CC Training Academy can teach you these and more when you enrol in our asbestos courses. The training is valuable if you want to become an asbestos removal professional or simply want to learn how to identify or best manage asbestos at home or in the office.

That said, here’s a quick overview of Class A and Class B asbestos, where they could be found, and what to do to have them removed from your property:

What is a class A Asbestos?

Class A asbestos is also commonly referred to as “friable asbestos.” This is the kind of asbestos that becomes dust or crumbles into a fine powder when dry. Class A is the more dangerous of the two kinds of asbestos because it can be crushed and release fibres with even the gentlest pressure or movement. Also, friable asbestos and ACMs can have as high as 100% asbestos percentage.

Friable asbestos products can usually be found in the following:

  • asbestos-contaminated dust (ACD), which can come from Class B asbestos
  • deteriorated Class B asbestos
  • floor tile backings
  • spray-on coatings
  • thermal insulation materials

To handle or remove Class A asbestos, you need to work with persons with a Class A removal licence. They are authorised to remove any amount of friable asbestos or ACMs, as well as Class B asbestos and even ACD.

The work will be conducted under full containment, which prevents particles from escaping. Any possible exits for the dust and fibres must be sealed, and air filtration devices capable of absorbing asbestos fibres must be used. Moreover, the workers and supervisor must wear proper PPE or personal protective equipment, particularly full-coverage masks to prevent inhalation of the dislodged asbestos fibres.

What is Class B Asbestos?

If Class A asbestos is considered friable, then Class B is considered “non-friable.” It’s usually mixed and sealed into other products like cement or plastic, which is also why it’s called “bonded” asbestos. It’s less dangerous than Class A, simply because the fibres are bonded more tightly to the main material, and the materials that contain Class B asbestos are usually not as easily crushed or crumbled.

Class B asbestos is usually present in the following:

  • bituminous products
  • cement products like cement sheets, pipes, gutters, and roofing
  • electrical resin products
  • vinyl composite tiles

Similarly, with Class A asbestos, you will need to work with a professional with a Class B removal licence to remove or handle the material. Those with a Class B removal licence can remove any amount of non-friable asbestos and ACM, as well as ACD produced by the removal of non-friable asbestos and/or ACM. The same PPE requirements apply, although there is no need to work in containment.

Do note that those with a Class A licence can also remove Class B asbestos, provided that they have appropriate Class B training. They should also be supervised by certified Class B supervisors. Again, while non-friable asbestos is considered less dangerous, it doesn’t mean that there are no risks involved.

In conclusion, when dealing with any form of asbestos, it’s best to leave it to the professionals. This way, everybody’s health and safety are ensured.

You should also consider taking an asbestos awareness course, even if you aren’t intending to acquire a Class A and/or Class B removal licence. Knowing is half the battle, as they say, and being able to identify the different kinds of materials that may contain asbestos is crucial to home and workplace safety.