Washington State University
Environmental Health & Safety General Asbestos Awareness: Online Training

What Is Asbestos?

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This asbestos shows filaments separating from its surface
Asbestos is the name for a group of naturally-occurring minerals that can separate into long thin fibers. Because it has so many useful qualities, asbestos has been widely used in industry and specific terms and definitions apply to it. Asbestos fibers are durable and light-weight.

Fibers can be either coarse and needle-like or curved and silky and can be woven into cloth.

Asbestos is most hazardous when it is friable.

Asbestos fibers have:

  • Relatively high tensile strength,
  • Good frictional properties,
  • Resistance to heat and cold,
  • Resistance to corrosive chemicals and bacteria, and
  • High electrical resistance.

Friable means it can be reduced to dust by hand pressure. Asbestos causes a health risk when microscopically small fibers break off and float in the air where they can be inhaled. These fibers are so small they may stay suspended in air for hours or even days.

Because it is naturally occurring, some fibers are already present in the air, with more contamination in cities due to wearing of asbestos-containing materials such as brake linings.

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