What is asbestos, and why is it still in so many buildings?
The mineral that built the modern house, and the reason we test before we touch it.
Asbestos is the name for a group of six naturally occurring fibrous minerals. The fibers are strong, flexible, heat-proof, rot-proof and microscopic, which made them perfect for building products and, once breathed in, a lasting hazard.
Prized, and already suspected
People wove asbestos into cloth and lamp wicks for thousands of years. Writers of the ancient world even noted illness among those who worked with it.
The industrial boom
Mining and manufacturing scaled up. Asbestos wrapped steam pipes and boilers, and spread into roofing, cement and insulation.
The building-boom peak
Postwar construction used asbestos in floor tile, siding, ceiling texture, plaster, joint compound, duct wrap and attic insulation. Most American homes from this era can contain some.
The health evidence becomes undeniable
Decades of data linked heavy exposure to asbestosis, lung cancer and mesothelioma. Regulation of specific products and workplace exposure began.
A broad ban is struck down
The EPA moved to ban most asbestos products, but a court ruling in 1991 overturned much of that rule, so many uses lingered for years.
The EPA ends ongoing chrysotile use
A 2024 EPA rule banned ongoing uses of chrysotile asbestos. It does not remove material already installed, which is why surveys still matter.
Where it hides in a Michigan home
You cannot identify it by sight. These are the places and eras where it is most often found.
| Material | Where to look | Typical era |
|---|---|---|
| Vinyl & asphalt floor tile | Kitchens, basements, under newer flooring, plus the black mastic glue | 1940s–1980s |
| Textured & popcorn ceilings | Living areas, bedrooms, hallways | 1950s–1980s |
| Pipe & boiler wrap | Basements and utility rooms with older heating | Pre-1980 |
| Cement siding & roofing | Exterior walls, shingles and flat roofs | 1920s–1970s |
| Vermiculite insulation | Attics and wall cavities, a pebbly grey-brown fill | Mid-century |
| Plaster & joint compound | Walls and ceilings | Through the 1970s |
Why avoid it
When asbestos-containing material is damaged and fibers float into the air, they can be inhaled and lodge deep in the lungs. The body cannot clear them. The diseases they cause, including asbestosis, lung cancer and mesothelioma, can appear 10 to 40 years later, and no safe level of exposure has been identified.
That is why the answer is never to guess. Find out first, then decide whether to leave it, contain it or remove it.
Not sure what is in your building? A licensed inspector can sample and tell you, usually before the lab results even come back.
Get an asbestos surveyQuick answers
What is asbestos?
Asbestos is the name for a group of six naturally occurring fibrous minerals that resist heat, fire and chemicals. Its fibers are strong, flexible and microscopic.
Is asbestos still legal?
Many uses were restricted over decades, but it was not fully banned for a long time. In 2024 the EPA finalized a rule ending ongoing uses of chrysotile asbestos in the U.S. Material installed long ago is still in many older buildings.
Why is asbestos dangerous?
When fibers get into the air and are breathed in, they can lodge in the lungs and cause serious disease years or decades later, including asbestosis, lung cancer and mesothelioma.
Can I tell if something contains asbestos by looking at it?
No. Materials with and without asbestos look the same. Only a laboratory analysis of a sample can confirm it.