Three Classes of ACBMs
EPA classifies ACBMs in three general categories
Thermal System Insulation (TSI)
Surfacing Material
Miscellaneous
Use in building materials was most common from about 1945 to 1980
Friable – definition:
A material that, when dry, may be crumbled, pulverized or reduced to powder by hand pressure
Includes previously non-friable material after it has been damaged to the extent that it has become friable
Sampling requirements under HAR §11-502:
A certified asbestos building inspector must take at least 3 samples of a homogeneous material, depending on the type of ACBM, in order to determine whether a suspect ACBM contains asbestos. All 3 samples must be shown to be ≤1% asbestos in order to be non-ACM. If one of the samples contains >1% asbestos, the entire homogeneous area (or unified sampling area - USA) is classified as ACBM.
Friable blown-on ceiling insulation. It is easy to imagine crumbling this material with hand pressure.
Non-friable materials can be made friable, if damaged. Vinyl asbestos floor tiles are generally not friable unless damaged. Failure to use wet methods has resulted in these floor tiles being damaged and becoming friable, with release of asbestos fibers.