Asbestos in plaster, filler and tile adhesive: advice for electrical and plumbing and heating businesses

Almost every tradesperson recognises asbestos cement on a roof. It is more difficult with plaster, fillers and tile adhesives. Until asbestos was banned, it was sometimes added to them, often in small quantities. Nothing can be seen from the outside; only a material sample with laboratory analysis gives certainty. The surfaces affected are exactly those that electrical and plumbing and heating businesses work on every day.

What a study in Bavaria measured

From 2017 to 2019, the Bavarian State Office for Health and Food Safety (Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit) examined building materials from buildings constructed before 1993. Around 40 per cent of the 70 samples, including tile adhesives, fillers and window putty, contained asbestos. The levels were mostly very low, but one tile adhesive contained 15 to 40 per cent amphibole asbestos.

For electrical work in wall plaster, the fibre concentrations measured for drilling and fitting sockets were below 10,000 fibres per cubic metre, i.e. in the range of the acceptable concentration. Abrasive methods were a completely different story: when using an angle grinder without extraction, up to 866,000 fibres per cubic metre were measured. The State Office notes that even products with a low asbestos content can release considerable quantities of fibres, and that sanding, milling and grinding release significantly more than manual work, even with extraction.

What the Hazardous Substances Ordinance (Gefahrstoffverordnung) requires

Work on materials containing asbestos is prohibited in principle. Exceptions include maintenance work, which covers functional maintenance as part of ongoing use, including adaptation to current construction standards (§ 11 Abs. 2 GefStoffV). Such work is only permitted if it does not give rise to a high risk, the material still fulfils its function and subsequent complete removal is not made significantly more difficult (§ 11 Abs. 5).

Before starting, the business must determine whether the work is permitted, whether fibres may be released and which risk range it falls into, and draw up a work plan (§ 11a Abs. 1). For many activities there are recognised low-emission methods that have been proven to remain in the low risk range (§ 2 Abs. 4c). Anyone using such a method can use its description instead of the work plan. The methods are compiled in DGUV Information 201-012. For drilling in walls, ceilings and floors, the Institute for Occupational Safety and Health of the DGUV (Institut für Arbeitsschutz der DGUV) lists several tested methods.

In practice

For buildings where construction began before 31 October 1993, it should be clarified before chasing, chiselling or tiling work whether the layers affected have been tested. Where this is unclear, sampling should be part of work preparation. On site, hand tools, direct extraction at the drilling point and avoiding cut-off grinders are the measures that make the biggest difference according to the Bavarian measurements.