Asbestos Identification

Asbestos is a cluster of fibrous silicates that belong to the amphibole and serpentine groups of minerals. Identifying asbestos is important since it is the first step to managing asbestos, a known health risk. To help ease the process, here’s a detailed look at the identification of asbestos.

Types of Asbestos

There are six different types of asbestos, each of which differs in character and appearance. As a result, they each have different levels of risk.

Chrysotile: Apart from being the only serpentine, chrysotile is also the most common and widely used type of asbestos. In fact, more than 95 percent of all ACMs are of the chrysotile variety. Because its long, curly fibers are crystal-like sheets, this type is commonly referred to as white asbestos. Chrysotile is known to cause asbestos-related health issues like mesothelioma.

Amosite: Also known as brown asbestos because of its brown-colored fibers, amosite is popular for being heat-resistant. As a result, it is the second most widely used type of asbestos. Exposure to amosite might lead to asbestos-related diseases like asbestosis, lung cancer, and mesothelioma. In fact, a study by the American Cancer Society shows that exposure to amosite creates a greater risk of cancer than every other type of asbestos.

Crocidolite: Also known as blue asbestos for its straight, blue-colored fibers, crocidolite is considered the most dangerous type of asbestos. Because these fine, needle-like fibers tend to break off easily, the human body finds it hard to expel them once inhaled or ingested. Because it is strong, durable, and fire-resistant, crocidolite was mostly used in thermal insulation, rope lagging, and spray-on fireproofing.

Tremolite: This type of asbestos has been used in a variety of industrial and commercial products because its white, gray, or green-colored fibers are strong, heat-resistant, and flexible enough to spin and weave into cloth. Inhaling the tiny, razor-like fibers is known to cause serious health issues.

Anthophyllite: As one of the rarest types, this white, gray, or brown-colored asbestos does not have a long history of industrial or commercial use. Although it’s not considered a serious health risk, exposure to anthophyllite has been linked to the development of mesothelioma.

Actinolite: Also rare, this type occurs in a variety of forms. It can be brittle and fibrous or dense and compact. Because it is often a contaminant to other minerals, actinolite is rarely used for commercial purposes. Although can occur in white, gray, brown, or green, actinolite is generally dark in color.

Types of Asbestos-Containing Materials

Thanks to its unique and extremely beneficial properties, asbestos has been used in the manufacture of various products. Asbestos-containing materials occur in either friable or non-friable form.

Friable asbestos: Apart from a tendency to contain high levels of asbestos, friable asbestos products are usually quite loose. Very light pressure is therefore enough to crumble them when dry, which will most certainly release asbestos fibers into the air. As a result, friable asbestos products pose a significant health risk. Friable asbestos products have been in use since the late 1800’s and can be found in homes built before 1990. Friable asbestos-containing materials include:

  • Pipe lagging
  • Boiler insulation
  • Sprayed insulation
  • Fire retardant materials

Bonded (non-friable) asbestos: Also known as fibro, these types of products are made using a bonding compound like cement mixed with a small proportion of asbestos, usually less than 15 percent. Since they are solid, rigid, and non-friable, you cannot crumble, pulverize or reduce bonded asbestos products to powder by hand pressure. When in good condition, bonded asbestos-containing materials do not usually release fibers into the air. As a result, non-friable asbestos products are considered low risk. However, bonded asbestos products can become friable when damaged or badly weathered. Non-friable asbestos-containing materials include:

  • Vinyl floor tiles
  • Bitumen-based waterproofing
  • Asbestos cement molded products
  • Asbestos cement sheet



Sources of asbestos in the home environment include:

  • Air conditioning ducts, including thermal insulation and exterior or interior acoustic
  • Ceiling tile
  • Sprayed insulation, popcorn or vermiculite asbestos ceiling
  • Electrical fuse boards
  • Cement conduits
  • Cement external roofs and walls
  • Asbestos cement molded products like ridge capping, gutters, cable troughs, gas meter covers, and covers
  • Cement sheet behind ceramic tiles
  • Internal asbestos cement sheets installed over exhaust canopies like ovens and fume cupboards
  • Asbestos cement sheet interior ceilings and walls
  • Cement sheet underlays for vinyl
  • Storm drain pipes
  • Cement water pipes, often underground
  • Roof tiles
  • Textile gussets in air conditioning systems
  • Door seals and gaskets on ovens
  • Electric high wattage light fittings and insulation around fixtures
  • Floor vinyl tiles
  • Fuse blankets and ceramic fuses in switchboards
  • Insulation in electrical heating units and air conditioners
  • Lagging in fireproof wall penetrations
  • Millboard lining of switch boxes
  • Millboard between heating units and walls
  • Pitch-based electrical switchboards
  • Pipe insulation including molded sections, rope braid, water-mix types, and sheet
  • Window sealant or mastic
  • Mastics and sealants in air conditioner duct joints
  • Sprayed acoustic wall and ceiling
  • Spackle or plasterboard wall-jointing compounds
  • Sprayed beams and ceiling slabs
  • Sprayed insulation for the bolts holding external wall panels and fire retardant
  • Old domestic type stoves
  • Wall insulation
  • Tapered ends of pipe lagging
  • Tilux sheeting, often installed in place of ceramic tiles


Tips on Identification

As asbestos comes in various shapes and sizes, identifying the presence of this mineral is not easy. It is always recommended to get it tested for 100% accuracy. Here are a few identification tips.

Determine when the building was constructed. If your building was built anytime from the early 1900s to 1989, odds are asbestos was used during construction. Buildings constructed after 1990 do not have ACM because asbestos products were no longer in production.

Check old construction materials for abrasions, discoloration, tears, water damage, and any other sign of wear or damage.

Check for evidence of degradation. Indications include:

  • Disintegrating construction features such as walls, pipes, vinyl tiles, insulation, and stovetop pads, especially those that have been present since the building was first constructed.
  • Dusty areas, cracks, and spots where the construction material is likely to break down and fall apart.

Safety Precautions

  • Wear the appropriate protective gear
  • Thoroughly wet the material before you start any work, and regularly during the work.
  • Use non-powered hand tools.
  • When removing asbestos sheeting, start by pulling out any nails to reduce the likelihood of breakage.
  • Try not to cut or break ACMs.
  • Properly remove and dispose of protective equipment.
  • Take a shower, wash your hair and clean your hands immediately afterwards.


If the work involved necessitates sanding, cutting wire brushing, scraping or drilling, contacting a certified and licensed professional is the best and safest option.

What if you suspect asbestos?

If you suspect asbestos, it’s probably best to treat each material as if it contains asbestos, especially since disturbed asbestos fibers are a serious health hazard. You should, therefore, have the area tested to determine the presence of asbestos. When it comes to testing for asbestos, there are several options.

If you are comfortable with the process, you can buy an asbestos testing kit. This kit allows you to take a sample, which you will have to submit for analysis. Only NATA-accredited laboratories can perform the analysis. Some testing kits come with a chemical that can test for asbestos. Unfortunately, the results will depend on variable factors, making such kits potentially inaccurate.

Engaging the services of a professional is the other option. Although it might be more expensive than the asbestos testing kit option, using a professional is a lot safer and provides more comprehensive results.

You can help manage the health risks associated with asbestos by finding out whether you have asbestos in your home. If present, you should then identify the location, quantity, and condition of asbestos. As dangerous as the fibers can be, asbestos identification plays a major role in its management.