Waste containing asbestos

Construction workers in white protective suits and respirators in a corrugated asbestos roof.Click to enlarge
When the asbestos protective clothing must be worn.
Source: Lucaz80 / Fotolia.com

The term “asbestos” means a family of naturally occurring fibrous minerals. In the past, asbestos was widely used in myriad products owing to its exceptional heat and chemical resistance, whereby white asbestos (chrysotil asbestos) and blue asbestos (crocidolie asbestos) were the types most commonly used.

Past application domains

In earlier times, asbestos was mainly used for construction, namely for pipes, large flat or corrugated sheets, or for small facade and roof panels.

Asbestos and materials containing asbestos were also used in consumer products such as planters, flower boxes, ashtrays, various types of electrical heating apparatuses and household appliances.
On site disposal
Household objects and minor amounts of household objects containing asbestos are collected by public sector recycling companies along with other minor amounts of pollutants. The main site disposal options in this regard are as follows:
• Disposing of the waste at recycling centres
• Collection at other public sector waste recycling facilities
• Landfill
• Disposing of the waste at storage facilities operated by asbestos disposal companies.

Waste containing asbestos is to be placed and transported in suitable securely closeable and clearly labeled receptacles. Such waste is to be kept separate from other wastes so as to avoid mixing with other materials that would enlarge the amount of asbestos containing waste or that would result in the asbestos content remaining unknown. In this process, local waste disposal regulations are to be adhered to.

Properties; health hazards

Asbestos exhibits two properties – its thermal resistance and its fiber structure – that made it useful for numerous applications and that resulted in large scale dissemination of products containing asbestos. Moreover, asbestos was a readily available and low cost material that readily lends itself to processing and is resistant to chemicals. But it is the very fiber structure of asbestos that makes its extraction, use and disposal hazardous. When subjected to mechanical stress, asbestos fractures into countless minute fibers which can enter the human body through respiration and can provoke lung cancer, asbestiosis, and mesothelioma, all of which are potentially fatal. In 1995, these health risks resulted in a ban on the manufacturing, marketing and use of asbestos products in Germany, whereby the EU followed suit shortly thereafter via Directive 1999/77/EC, which completely banned the use of asbestos.

Hence asbestos release and inhaling asbestos must be avoided at all costs. In terms of asbestos disposal, this entails either destruction of the fiber structure or permanently removing asbestos waste from the biosphere. In Germany, waste containing asbestos is normally disposed of permanently in special landfill sites or sections thereof. Unfortunately, attempts at large scale asbestos fiber destruction with concurrent cement matrix recycling have been unsuccessful.

Classification and disposal of waste containing asbestos

Council Decision No. 573 of 23 July 2001 classifies waste containing asbestos as a hazardous, including construction waste containing asbestos that is embedded in the binder matrix (e.g. asbestos cement). This classification was solely determined by the potential health risks of the materials in question, and not by the degree of risk entailed by the release of asbestos fibers into the environment. The fact that this hazard is designated as H7 (carcinogenic) in Directive 2008/98/EC Annex III means that all types of waste containing asbestos listed in the European Waste List constitute hazardous wastes whose transport and disposal are subject to specific regulations. Disposal of asbestos containing waste is governed in Germany by regional-state laws, whose provisions differ slightly from each other in some cases. The LAGA (Federal States Working Party on Waste) has issued a guide to implementation of these rules (Mitteilung M23), which is updated at regular intervals.

If some products containing asbestos (e.g. asbestos injected into steel frameworks as a fire safety measure, ship fire walls, thermal clothing, sealants, brake shoes and filters) are relevant solely for very specific professions, other products are used virtually everywhere, including electrical heating devices such as night storage heaters, as well as asbestos-cement pipe, roof and facade structural elements.

Asbestos in night storage heaters tends to turn up in various components, whereby the stones that actually store the heat may contain chrome VI compounds and other pollutants. Hence by law, only specialized companies are permitted to dismantle and dispose of such apparatuses.

Asbestos cement structural elements that were made using fiber bonding were manufactured in Germany until around 1990. These elements are composed of up to 15 percent asbestos fibers, which endow the brittle cement matrix with limited bend strength, thus allowing for the production of large, thin structural components. Such fibers are only released if the bond between them and the cement stone is eliminated via mechanical or physicochemical forces. Hence it is essential to ensure that such elements are not damaged while being dismantled and disposed of. Normal weathering can also eliminate the bonds between fibers. However the extent to which this weathering poses a risk needs to be assessed on a case by case basis.

Owing to the fact that buildings tend to last a long time, many structural elements containing asbestos are still in use and need to be disposed of as hazardous waste.
Asbestos-free construction products that strengthen the inorganic binding matrix of fibers made of organic polymers (asbestos cement) or glass fiber reinforced concrete have been on the market for many years now. Fibers of this type are too large to enter the lungs. Components containing these materials are not readily recognizable as asbestos free elements, notwithstanding their having been expressly designed as an asbestos substitute for structural sizes and forms similar to those used for asbestos cement. The legacy trade name “Eternit” is still used for some of these products. In case of doubt, only a thorough investigation can determine whether a given material contains asbestos.