Why Most Building Materials Are Suspect for Asbestos Assume until proven otherwise—how to think about suspect materials before disturbance Suspect Materials • Risk Screening • Smart Planning

Colorado and the EPA both require contractors and inspectors to assume that many common building products may contain asbestos until proven otherwise. This applies to homes, schools, and commercial buildings of all ages. The easiest way to know if a material is suspect is to list the few materials that are not suspect: pure wood (framing, planks, boards, etc.), glass, metal, ceramic and fiberglass. If it's not one of those materials, it's probably suspect.

1. What “Suspect Materials” Means
A suspect material is any building material that could contain asbestos, based on historical manufacturing practices and product use. Examples include:

• ​Wall textures
• Drywall and joint compound
• Ceiling textures and plaster
• Floor tiles and adhesive/mastic
• Roofing, siding, shingles, mastics
• Pipe insulation, duct wrap, fireproofing   ​
• These are so common that the EPA and CDPHE say: assume they contain asbestos unless tested.

2. Age of the Building Does Not Guarantee Safety
Many people believe asbestos was “banned” decades ago — but it was never fully banned in the U.S. Even materials installed in the 2000s or later can contain asbestos, since some asbestos-containing products are still legal and imported today. The EPA’s “Purple Book” (Guidance for Controlling Asbestos-Containing Materials in Buildings) emphasizes that visual inspection alone cannot determine whether asbestos is present. Sampling and lab testing are the only reliable methods.

3. Why the Rules Require Caution
EPA (AHERA, NESHAP) and Colorado Reg 8 both mandate inspections before disturbing suspect materials in regulated projects. OSHA (29 CFR 1926.1101) requires employers to treat suspect materials as ACM unless proven otherwise by testing. This framework protects workers, building occupants, and the public from exposure to asbestos fibers.

4. Why This Matters for You

• Health risk: Asbestos fibers are microscopic — you can’t see them, but they can cause asbestosis, lung cancer, and mesothelioma.
• Hidden liability: Renovating without testing may expose workers or tenants, creating legal and financial consequences.
• Peace of mind: Testing suspect materials up front provides certainty and prevents project delays.

✅ In Plain English
​Most building materials are considered “suspect” for asbestos, no matter how old or new your building is.

• Age is not a reliable indicator.
• The only way to know for sure is laboratory testing.
• That’s why inspections and sampling are required before disturbing these materials.

References for Those Who Want to Read More

• EPA “Purple Book” – Guidance for Controlling Asbestos-Containing Materials in Buildings (EPA 560/5-85-024, June 1985, still cited today)
• EPA Restrictions on Use of Discontinued Asbestos EPA →
• Colorado Regulation No. 8, Part B – Asbestos CDPHE →
• OSHA 29 CFR 1926.1101 – Construction Asbestos Standard OSHA →