Follow-up report on the 29th Forum on Asbestos and Other Pollutants in Technical Structures
The 29th Forum Asbestos took place in Essen at the beginning of November. Due to the worsening infection situation, we did not have a booth on site this year but participated in the online offerings of the event. We have summarized some impressions of the event for you in this follow-up report.
The building pollutant asbestos from a Swiss perspective
Dealing with asbestos continues to be an issue in our neighboring countries as well. In his presentation, Clemens Jehle focused on Switzerland, where asbestos has been banned for 30 years. In addition to a historical summary, the topics of education and training, asbestos analysis, and asbestos-containing waste were discussed.
While sprayed asbestos floor coverings and lightweight building boards containing asbestos were considered to have been largely cleaned up in the 2000s, the importance, and prevalence of other building materials containing asbestos, such as window putties, floor coverings, adhesives, fillers, tile adhesives, and plasters, had been underestimated, as was the case in Germany. In recent years, the Swiss Accident Insurance Fund (SUVA) has tightened up several regulations and launched campaigns to increase the focus on asbestos. Although the limits have been lowered several times, cases of asbestos-related diseases continue to rise to this day; the peak does not yet seem to have been reached. At the same time, the amount of asbestos-containing waste has increased sharply.
Asbestos-containing fire dampers and guideline on the asbestos investigation
Olaf Dünger of Competenza provided information on the latest developments in building pollutants. In the case of fire dampers containing asbestos, the asbestos guideline (more than 20 years ago) provided for long-term reassessment without a direct need for remediation. In the meantime, there is a risk that the aged asbestos foam will slowly decay, which is accelerated by damper tripping. Measurements have shown that fibers are released when the leaf hits the gasket. The German Association of Building Pollutant Remediation Services (GVSS) is expected to issue a recommendation for action on this in January 2021, advising rapid replacement of fire dampers containing asbestos.
Since April 2020, a "Guideline for Asbestos Investigation in Preparation for Work in and on Older Buildings" has been available for download. This non-normative guideline is intended to support craftsmen in particular, but also do-it-yourselfers. It pays particular attention to the quality of sampling: because if samples are not taken professionally, not only risks arise. The determination of the absence of asbestos by a negative laboratory result can also be made unnecessarily difficult.
Occupational safety: Working on contaminated structures
Martin Kessel of Arcadis Germany spoke at the Asbestos Forum about various innovations in the field of contaminant detection in the normative area. The April 2020 report of the Committee on Waste Technology on the handling of construction and demolition waste with low asbestos content again raises the question of what is considered "asbestos-free." Several possible definitions are being considered:
- Structures constructed more than 2 years after asbestos was banned (with no indication that building materials introduced into commerce before 1993 were used)
- Buildings renovated to the current state of asbestos technology
- Buildings with an asbestos-free certificate issued by a recognized expert
- Suspicion of asbestos eliminated by appropriate sampling and analyses
Particularly in the case of demolition, preliminary investigation plays a central role, as the subsequent inspection of construction waste for asbestos is much more complicated. If, for example, materials containing asbestos have been used in a building, but these cannot be separated before demolition, then the total content of asbestos in the construction waste could slip below the detection limit due to the dilution effect. This should not result in the waste subsequently being assessed as free of asbestos.
Status of the National Asbestos Dialogue
Andrea Bonner from the Federal Ministry of Labor and Social Affairs reported on the current status of the National Asbestos Dialog. The future cornerstones of the asbestos regulations are to be laid down in the Hazardous Substances Ordinance – including the occasion-related duty of investigation for the initiator of activities in existing buildings. The presumption is that all buildings erected before the asbestos ban are contaminated with asbestos. Overview of further developments and relevant contents:
- Concretization of the prohibition of overlapping
- A more precise description of permitted activities as exceptions to the prohibition of the use
- Definition of risk-based protective measures
- Adoption of activity prohibitions from the Ordinance on Hazardous Substances
- Description of permitted activities (e.g. activities for analysis purposes)
- Requirements for activities involving asbestos (based on the risk-based concept of the Hazardous Substances Ordinance and TRGS 519)
Asbestos in building rubble and recycled building materials
Dr. Bernd Sedat of Sachverständigenbüro Sedat addressed the question of asbestos in quality-controlled recycling materials. To keep recycled building materials free of asbestos, it is necessary to monitor the quality of building rubble according to VDI 3876 and to take samples according to LAGA PN 98. 77.7% of construction waste (approx. 45.5 million tons; as of 2016) is returned to the economic cycle as a recycled construction material. In this way, natural resources are conserved. More than half of the recycled building materials are used in road construction. In the new trades as well as in the preparation or processing, no carried-over asbestos should appear.
Low-emission methods in asbestos abatement
Gerald Lotz of Nassauische Heimstätten Wohnungs- und Entwicklungsgesellschaft mbH spoke about the advantages and disadvantages of so-called low-emission methods in asbestos abatement. A common problem in occupied housing stock: asbestos-containing plasters and fillers are to be removed from apartments where there is not enough room for conventional asbestos abatement with the appropriate protective measures such as 4-chamber airlocks.
The low-emission process developed has the advantage of eliminating the need for costly compartmentalization. Besides, the reduced site equipment and the elimination of the need for open-air measurements save time and costs.
The 29th Forum Asbestos was an exciting event with many informative technical papers. You can read even more detailed explanations of the topics touched on here and others in the extensive scilogs.spektrum.de blog entry by our colleague Dr. Gunnar Ries. The online event was a good opportunity to find out about new developments concerning asbestos as a building pollutant, even under the current pandemic conditions. However, we missed the otherwise also usual and appreciated personal meetings and discussions. Therefore, we hope to be there again next year.