The best way to get a smooth finish is to sand the glue off the wood. However, if there is asbestos in the glue, sanding it will cause the asbestos to become airborne, thus contaminating the entire house. Normally sheetrock does not contain asbestos, but the joint compound used on the seams between the pieces of sheetrock can contain asbestos. This is common on sheetrock walls and ceilings. Visual inspection can not determine if there are asbestos fibers in it.
Asbestos fibers are very small and some times invisible to the human eye.
As a result, microscopic analysis is the only way to determine if a product contains or does not contain asbestos. PLM is the US EPA accepted method. Sampling of suspect asbestos materials must be performed by an inspector accredited by the State of North Carolina. Inspectors are trained to look for certain materials in buildings that may contain asbestos and are also trained in proper sampling techniques. At present there is no requirement to remove asbestos materials from commercial and industrial buildings unless the identified asbestos material has deteriorated to the point that it may become air-borne and, therefore, a possible health hazard.