Types of Asbestos
Asbestos has been used for centuries for its insulating and fireproof qualities. As far back as the Stone Age, asbestos was used to strengthen pottery.
The term “asbestos” stems from an Ancient Greek word in the 1600s that means "inextinguishable.” This origin is fitting, as asbestos is a dangerous and pervasive substance. Asbestos is a naturally occurring class of minerals that form long, thin, very strong fibers.
Disturbing asbestos minerals or other asbestos-containing material may release tiny asbestos fibers into the air. Inhalation of these fibers over an extended period of time causes asbestosis, lung disease, lung cancer and mesothelioma. Many of these conditions can be fatal. It wasn’t until July 12, 1989 that the Environmental Protection Agency issued a final rule banning most asbestos-containing products.
The legal definition of asbestos applies to six fibrous minerals in two general classes:
- Serpentine class: chrysotile (also known as white asbestos)
- Amphibole class: amosite (brown asbestos), crocidolite (blue asbestos), anthophyllite, tremolite, and actinolite
Fibers found in the Serpentine class are softer and more flexible when compared to Amphibole asbestos, where the fibers are brittle and hard. This makes asbestos found in the Amphibole class more difficult to expel from the lungs, and therefore more dangerous. All six types of asbestos, however, can cause chronic and debilitating disease.
Here are the six main types of asbestos.
Chrysotile (white asbestos):
This was the most commonly used form of asbestos worldwide. It is the only member of the Serpentine family. As much as 90% of commercial asbestos once in use was white asbestos. Its soft and malleable fibers were frequently used in roofing material, fire blankets and safety clothing. The automotive industry used chrysotile asbestos in clutches, gaskets and brake linings. Other uses for the Serpentine class of asbestos were pipe insulation and floor covering.
Amosite (brown asbestos):
Amosite is the trade name for grunerite, the majority of which was mined in South Africa. In building insulation and ceiling material, Amosite is light brown in color, so it is also referred to as brown asbestos. You can find it present in ceiling tiles, soffits and door linings among other.
Crocidolite (blue asbestos):
This is the most hazardous type of asbestos because it easily crumbles when it is disturbed. Crocidolite asbestos was predominantly used in cement products, pipe insulation and spray coating. Historically, blue asbestos was commonly used to insulate steam engines.
This type of asbestos was not widely used in commercial production because, though it is brittle, it has low tensile strength. This type of asbestos could be found in vermiculite, talcum powder, and composite flooring.
Tremolite: This asbestos was only mined in limited quantities. It was used as a component of cement sheets and ceramics, as well as gaskets and fire doors. Tremolite can appear brown, white, green, gray or transparent.
This type of asbestos is the darkest colored asbestos. Its long fibers are sharp and easily inhaled. Actinolite was not mined itself, but can be found in loft insulation, sealants, and other fireproofing material.
It takes an experienced environmental consultant to identify the presence of asbestos in your home or business.
When you need the professional services of St. John Environmental Consulting, an AHERA accredited inspector will help you to determine the appropriate asbestos sampling plan and protocol to ensure that you protect yourself from health impacts and liabilities of asbestos, without wasting money on abating unnecessary materials.