Suspect material
Building material suspected of containing asbestos, e.g., surfacing material, floor tile, ceiling tile, thermal system insulation, and miscellaneous other materials.

Friable asbestos
Any material containing more than one percent asbestos, and that can be crumbled or reduced to powder by hand pressure. (May include previously non-friable material which becomes broken or damaged by mechanical force.)

Actinolite
Actinolite is the intermediate member; when iron is predominant the mineral is ferro-actinolite and when magnesium is predominant, the mineral is tremolite. The iron produces a green color that darkens as the iron content increases. Actinolite may occur in fibrous form (an asbestos). It is not used commercially, but is a common impurity in chrysotile asbestos.

Stage 1 Mesothelioma
Stage 1 mesothelioma affects one layer of the pleura only. It may have grown into the covering of the heart (pericardium) and the diaphragm

Anthophyllite
A type of asbestos in the amphibole group; it is also known as azbolen asbestos.

Permissible Exposure Limit (PEL)
An Occupational Safety and Health Administration (OSHA) allowable exposure level in workplace air averaged over an 8-hour shift of a 40 hour workweek.

Asbestosis
A progressively restrictive fibrosis of the lung and is recognized as a disabling and fatal occupational disease.

Tremolite
Tremolite may occur in fibrous form (an asbestos). It is not used commercially in the United States, but is a common impurity in chrysotile asbestos and vermiculite mined from deposits in Libby, Montana.

Stage 2 Mesothelioma
Stage 2 mesothelioma has spread to both layers of the pleura on one side of the body only

Fibrogenic
Causing or contributing to the fibrotic response mechanism in tissues; commonly refers to substances that contribute to fibrosis of the lungs or liver.