ASBESTOS
Friable material

Friable asbestos-containing material (ACM) is defined as any material containing more than one percent (1%) asbestos.

This is evaluated by using the method specified in the EPA rules, that, when dry, determine if it can be crumbled, pulverized or reduced to powder by hand pressure. Non-friable material

Non-friable ACM is any material containing more than one percent (1%) asbestos as determined using the method specified in the EPA rules, that, when dry, it cannot be crumbled, pulverized, or reduced to powder by hand pressure.

EPA also defines two categories of non-friable ACM -- Category I and Category II non-friable ACM -- which are described later in this guide.

Courtesy of The EPA: NESHAP Regulated Asbestos Containing Materials Guidance