Details

Besides obvious asbestos applications in buildings (e.g. asbestos cement), chemical construction products were used in Germany between around 1960 and the mid-1980s to which asbestos was added, either as a reinforcement or for modification of the application properties. Typical products are fillers, adhesives (e.g. for tiles) and plasters. These product types were manufactured and used both with and without asbestos. During work in existing buildings, such product applications are inadvertently worked mechanically. Since it is not immediately apparent whether materials in wall structures contain asbestos, a special surveying and sampling concept is required by which it can be determined with sufficient statistical accuracy whether asbestos will be encountered during the planned work.

The concept involves taken samples from the wall structure in which (in contrast to samples of archetypal technical asbestos products) it must be possible to detect asbestos even at very low concentrations of < 0.1% by mass. Due to the particular properties of the samples a special preparation strategy has been developed. The aim of this strategy is, on the one hand, to enhance the visibility of asbestos where present (uncovering of fibres, elimination of disturbing components) in order to facilitate subsequent scanning electron microscopy; and on the other, for preparation to be sufficiently gentle to prevent excessive breakdown of the chrysotile that may render it invisible for analysis.

With regard to the analysis of material samples, a comprehensive measurement campaign is also being conducted for the surveying of exposure to asbestos and dust (silica, respirable and inhalable dust) arising during various tasks performed in existing buildings. The German Social Accident Insurance Institutions are conducting reference measurements on a large scale and with use of particular protective measures, the purpose of which is to define low-emission methods for as many of the tasks as possible.