- ACM
- Asbestos-containing material — any product with more than 1% asbestos by weight.
- PACM
- Presumed asbestos-containing material — older suspect material treated as positive until a test proves otherwise.
- Friable
- Material that crumbles under hand pressure and therefore releases fibers easily.
- Non-friable
- Asbestos bound into a hard material such as floor tile or stucco; a hazard mainly when cut or broken.
- PLM
- Polarized Light Microscopy, the standard lab method for identifying asbestos in bulk building samples.
- Point count
- A more precise PLM technique used when asbestos content sits close to the 1% regulatory threshold.
- Homogeneous area
- A section of material that's uniform in color, texture and installation date — each one needs its own sample.
- Chain of custody
- The signed paper trail tracking a sample from collection to laboratory analysis.
- Chrysotile
- White asbestos, by far the most common type found in U.S. residential materials.
- Amosite
- Brown asbestos, typically found in insulation board and thermal products.
- Encapsulation
- Sealing or covering asbestos material in place instead of removing it — often the least expensive compliant option.
- Abatement
- Licensed removal of asbestos material under containment, carried out by a certified abatement contractor.
- NESHAP
- Federal air-quality standard requiring asbestos testing and notification before most demolition and renovation work.
- State environmental agency
- The state-level agency that enforces asbestos and demolition air-quality rules alongside federal requirements.
- State health department
- The state agency that typically licenses asbestos inspectors and abatement contractors and enforces state asbestos rules.
