Follow-up report: 30th Forum Asbestos and Other Pollutants in Technical Structures
On November 11 and 12, 2021, the 30th Forum Asbestos took place at the Haus der Technik, Essen. After we were only able to participate in the online offerings of the conference in 2020, we were again on site in person at the 30th Forum. Here is a summary of our impressions of the event:
On the current asbestos situation in Switzerland
As in the previous year, Clemens Jehle gave an interesting insight into the current asbestos issues and developments in Switzerland.
In order to improve the quality of asbestos analyses and analysis reports, the Swiss Association for Building Pollutants FAGES has adopted a new guideline. This specifies the minimum requirements for reports on material and indoor air samples for asbestos. In addition, the guideline addresses requirements regarding the independence of inspections and the issue of recumbent dusts. Experience has shown that asbestos can repeatedly be detected in recumbent dusts, while no relevant asbestos exposure can be measured in the room air. Therefore, the question arises to what extent these dusts can be used as a benchmark for the quality of a renovation or for a risk assessment.
In Switzerland, room air measurements according to VDI 3492 are often carried out incorrectly or at least problematically. For example, the measurements for success control are made by the remediator himself, no visual control is carried out, the utilization simulation is implemented incorrectly or omitted completely, self-protection (PPE) is omitted, the devices are not maintained or calibrated, measurement conditions are not recorded in the protocol and reports are neither complete nor comprehensible. Whether these problems are unique to Switzerland, where (as in Germany) there is increasing price pressure, could not be clarified.
News in the field of asbestos abatement:
- Foundation of an association of asbestos abatement contractors
- Increasing number of specialist firms for asbestos removal recognized by SUVA
- Decreasing number of trainees for asbestos removal according to EKAS guideline 6503 (the Swiss counterpart to TRGS 519 in Germany) - possible reason: increased requirements for asbestos removal specialists
Building pollutants: News from Germany
Olaf Dünger of Competenza GmbH spoke at the 30th Forum Asbestos about the latest building pollutant developments in Germany.
- March 2021: GVSS recommendation for action on the subject of fire dampers containing asbestos.
- June 2021: DGUV Information 201-012 on the subject of low-emission procedures in accordance with TRGS 512 for activities on materials containing asbestos.
The outdated low-emission method of burst lining is coming under increasing criticism. In this rehabilitation method for fiber cement pipes, the existing old pipe is burst and displaced into the surrounding soil. An entry must be made in the register of contaminated sites and the value of the property may be reduced as a result. The method may therefore only be used with the consent of the landowner and only in exceptional cases - if considerable difficulties and additional costs would otherwise have to be expected, such as when crossing under roads, railroads or bodies of water. In Bavaria, burst lining is not permitted.
Remediation methods with low asbestos exposure
Andrea Bonner of the Ministry of Labor and Social Affairs spoke about the importance of low exposure procedures and their timing at the 30th Asbestos Forum. Tested, standardized work procedures are designed to ensure that employee exposure is below the applicable limit (still 15,000 fibers/m³ of indoor air at the outset) and that when work is performed indoors, it is not contaminated upon completion.
According to TRGS 910, which was revised in 2014, the acceptance concentration of 10,000 fibers/m³ of room air must not be exceeded for activities with low exposure. For activities inside buildings, the indoor air concentration must be below 500 fibers/m³ and the upper Poisson value below 1,000 fibers/m³. Low-emission processes are mandatory for refurbishment and maintenance involving surface removal; for demolition work, they should at least be given preference.
In the future, the requirements for the permissibility of repair work are to apply:
- No high risk for the employees as well as no danger for other persons
- The useful life of the asbestos-containing material must not have been reached
- Prohibition of covering: Asbestos-containing material must not be concealed in such a way that later detection is considerably impeded or prevented
- Later complete removal of the asbestos-containing material must not be made significantly more difficult
Dr. Simone Peters of BG Rohstoffe und chemische Industrie spoke about the development of new processes with low asbestos exposure. The following regulations are relevant for this:
TRGS 519 (above all the exposure-risk matrix) - especially for work on construction chemical products containing asbestos, such as the plasters, fillers, and tile adhesives.
DGUV Information 201-012 "Low-emission procedures in accordance with TRGS 519 for work on materials containing asbestos".
The challenges of implementing low-exposure procedures in practice were discussed by Christoph Hohlweck of the German Pollutant Remediation Association at the 30th Asbestos Forum.
For example, the question was raised as to what extent the low-emission procedures under TRGS 519 are compliant with the rules. They do not require ventilation measures, although asbestos fibers are released (cf. GefStoffV $ 7, basic obligations, adequate ventilation). In addition, they (often) do not (any longer) correspond to the state of the art with regard to minimizing asbestos exposure.
Asbestos in building rubble and recycled material
In his comments on VDI 3876 in practice, Dr. Bernd Sedat of Sachverständigenbüro Dr. Sedat reported on how difficult it is to remove asbestos that has found its way into recycling material. On the stockpile, he said, it might still be halfway possible to separate afterwards; after processing and crushing into smaller grain sizes, it would be almost impossible. Dr. Philipp Stelter of APC GmbH described similar experiences. In tests of samples from various construction waste processing plants, asbestos was detected in all of them. 8 out of 20 laboratory samples examined contained asbestos, 2 even above a level of 0.005% by mass.
Dr. Alexander Berg of AB-Dr. A. Berg GmbH spoke about conflicts and possible solutions for the reuse of building materials. In order to prevent the uniform distribution of asbestos in new construction projects and to avoid conjuring up an endless remediation story, it is necessary to prevent asbestos-containing construction debris from entering the recycled product during the production of recycled building materials.
Before demolition, buildings must be stripped of asbestos in a regulated process (in accordance with VDI 6202 Sheet 3). A control method should exist here to check that it has been carried out properly. Dr. Berg's suggestion for identifying contamination hotspots in building rubble: hotspot sampling according to LAGA PN 98 and application of the statistical approach of VDI 6202 Sheet 3.
What is geogenic asbestos?
Geogenic asbestos is asbestos that has not been deliberately added to the material to improve its properties. Unlike "technical asbestos," these asbestos minerals have been carried along as "free riders" along with other aggregates, or they are part of the natural mineral paragenesis of a material.
At the 30th Asbestos Forum, Dr. Kay Menckhoff of Wartig Nord Analytik GmbH explained the differences between the two types of asbestos minerals. Chrysotile in particular, but also amosite, crocidolite and anthophyllite are technically frequently used asbestos species. Other asbestos types are rarely used technically, but appear in aggregates. Tremolites, for example, can occur in PVC, where they reveal themselves by their energy-dispersive element spectrum and their fissility.
Morphological criteria to distinguish technical and geogenic asbestos:
- Technical asbestos:
- Extremely fibrous and needle-like.
- Uniform fibers
- Mostly respirable
- Geogenic asbestos:
- Often fissility typical of asbestos, very thin fibers in places
- Often columnar or prismatic minerals
- Dimensions are often clearly above the WHO criteria for respirable fibers (however, respirable fibers can be released quickly due to easy fissility)
Fire dampers containing asbestos
Dr. Uwe Koop of IBUK GmbH gave recommendations on how to deal with fire dampers containing asbestos. For example, a building owner must regularly prove that the fire dampers are in good working order. Mostly, testing organizations refuse to carry out functional tests without extensive protective measures according to TRGS 519. However, anyone who operates a building without complying with fire protection regulations is liable to prosecution.
René Laarmann from Bau- und Lieganschaftsbetrieb NRW showed how fire dampers containing asbestos can be replaced at the end of their service life with low emissions. It should be noted that, in addition to the damper blade, the stop seal can also contain asbestos. Michael Mund of Ingenieurbüro Mund explained which regulations apply to the renovation of fire dampers containing asbestos.
VDI Guideline 6202 Sheet 3
Martin Kessel of Arcadis Germany GmbH reported on initial practical experience with VDI Guideline 6202 Sheet 3 "Asbestos - Investigation and Assessment," which was published in September.
This new guideline is aimed at all those involved in construction, such as building owners, planners, experts, and contractors, and provides them with assistance, for example in drawing up a sampling plan. It applies to the investigation and assessment of asbestos in structural and technical installations, both during operation and during construction measures, valuation or demolition. However, it does not apply to earthworks, landfills, and contaminated soils.
Conclusion
We were pleased to be able to attend the Asbestos Forum in person again. In addition to the exciting technical presentations, we were able to enjoy the exchange with other conference participants, colleagues and old acquaintances. You can read an even more comprehensive follow-up report on the 30th Forum Asbestos in the scilogs.spektrum.de blog entry by our colleague Dr. Gunnar Ries.
