Friable Vs. Non Friable Asbestos

Friable Vs. Non Friable Asbestos

Asbestos was a popular ingredient in building materials for many years because of its indestructibility, insulating properties, tensile strength and low electrical conductivity. It is still used in the U.S. today, but a distinction is made between more and less dangerous asbestos-containing material (ACM). More dangerous ACM can release asbestos fibers into the air where they can be inhaled and cause illness. Less dangerous ACM generally coats or encapsulates the asbestos fibers with cement, plastics, or asphalt so that they are not easily released into the air. The more dangerous ACMs have been banned or voluntarily replaced to a large degree, while some of the less dangerous ones remain in use.
The U.S. Environmental Protection Agency (EPA) made this distinction when first regulating ACM under the National Emission Standards for Hazardous Air Pollutants (NESHAP) in 1973. They called the more dangerous type of ACM "friable." Friable asbestos-containing materials were officially defined as those materials containing more than 1% asbestos which could be crumbled, pulverized or reduced to powder by hand pressure when dry, using methods specified in the NESHAP rules.
The EPA called "non-friable" the generally less dangerous form of ACM, not very likely to release asbestos fibers into the air. A non-friable ACM is a material containing more than 1% asbestos but not able to be crumbled, pulverized or reduced to powder by hand pressure when dry, using the same methods (1).
The terms "friable" and "non-friable" are not necessarily meant to pertain to a particular material for its entire lifetime. Some materials will always be friable by their nature, particularly the lightweight uncapsulated ACM once used for insulation. But the EPA has determined that otherwise non-friable ACM can become friable if it is damaged or worn enough (2).  Cutting or grinding or sanding a non-friable material like asbestos-containing cement, as the homeowner might do during renovation, for instance, would create large amounts of dust which might contain significant amounts of asbestos fibers which had been freed from their binding material by the pressure exerted by power tools.

NESHAP therefore regulates both friable ACM and non-friable ACM which is likely to become friable when acted upon during demolition or renovation, or when degraded during its natural lifetime by the weather or other forces it might be exposed to. Non friable asbestos ACM may be either Category I or Category II, which is generally a division reflecting its probability of becoming friable over time, and its relative danger after being disturbed or degraded. Federal laws defined by NESHAP as well as the Department of Labor, Occupational Safety and Health Administration (OSHA) rules for asbestos workers—plus more stringent laws on state and local levels for handling, transporting and disposal—will differ depending on whether the ACM in question is friable or non-friable Category I or Category II, and whether it shows damage or is likely to be damaged by the kind of action to be taken (3).