Which asbestos fiber types are commonly regulated in construction, and which is most prevalent?

• A. Amosite is the most prevalent in construction; chrysotile is not regulated.
• B. Crocidolite is the most prevalent in construction; chrysotile is regulated.
• C. Chrysotile (serpentine) is the most prevalent in construction; amphibole forms include amosite, crocidolite, tremolite, actinolite, and anthophyllite.
• D. Tremolite is the most prevalent; other forms are also regulated.

Answer: (C)

Asbestos in construction comes in two main mineral groups: serpentine (chrysotile) and amphibole forms (such as amosite, crocidolite, tremolite, actinolite, and anthophyllite). Chrysotile is by far the most commonly encountered asbestos in building materials and applications, making it the predominant type you’d expect to regulate in typical construction scenarios. All asbestos types are regulated due to health risks, but the material you’d most likely find and need to manage in construction is chrysotile, with the other regulated forms belonging to the amphibole group. The other options misstate which type is most prevalent and don’t reflect the broad regulatory stance on all asbestos forms.