Development of a testing method for asbestos fibers in treated materials of asbestos containing wastes by transmission electron microscopy.

•A high sensitive and selective testing method for asbestos in treated materials of asbestos containing wastes was developed.•Asbestos can be determined at a limits are a few million fibers per gram and a few μgg−1.•High temperature melting treatment samples were determined by this method. Asbestos fiber concentration were below the quantitation limit in all samples, and total fiber concentrations were determined as 47–170×106g−1.