Background

Asbestos–Containing Materials (ACM) may be present at the NIH as pipe, duct and equipment insulation; core material of Virginia Metal wall partitions; original wooden doors; acoustical ceiling plaster; ceiling tiles, duct mastic; floor tiles and their associated mastic; asbestos-cement sheets (transite board) and spray-on fireproofing. These materials are most commonly found in mechanical rooms, pipe chases, stairwells and above suspended ceilings.

The potential for asbestos-containing material to release airborne fibers depends on its’ degree of friability. Friability is the ability of materials, when dry, to be crumbled, pulverized, or reduced to powder by hand pressure. The sprayed-on or troweled-on materials used as acoustical plaster on ceilings or as fireproofing is considered friable and readily releases airborne fibers if disturbed. Materials such as vinyl-asbestos floor tiles are considered non-friable and do not release airborne fibers unless sanded or broken. Transite board can release fibers only if sawed, drilled or broken.

Whenever suspect asbestos containing materials are encountered in a work area at the NIH, the presence or absence of asbestos will be confirmed by sampling and analysis conducted by the DOHS.

Information regarding the NIH locations where the presence or absence of asbestos has been documented is maintained by the Technical Assistance Branch (TAB), DOHS.