When the toxic asbestos fibers get inhaled, they can trigger health problems such as asbestosis, mesothelioma and lung cancer. The U.S. Government set forth a number of rules and regulations on working with asbestos cement products.
An individual’s health is at a high risk during the mining and production processes. Studies indicated that the installation of asbestos products is not completely free of risk either, but rather marginal. The EPA declared a material that contains asbestos only as potentially dangerous if it is friable. Friable means, that it can be broken up further, crumbled or pulverized by hand pressure. Therefore, asbestos cement cannot be considered hazardous, since it is not friable. The cement binds the asbestos fibers which prevents them from getting airborne, if the product is used under normal conditions.
However, when deterioration or any other disturbance causes the product to chip, grind, or if it's being sawed or sanded, the dust particles get released to the air, then asbestos cement materials are considered friable.
The National Institute of Building Science (NIBS) published a paper called 'Asbestos Operations and Maintenance Work Practices', which is alongside with another EPA publication ('Managing Asbestos in Place'), a commonly accepted guideline regarding the maintenance and management of asbestos cement products. It is advisable to strictly follow these recommendations to avoid asbestos cement products becoming friable during remodeling work, abatement or restoration projects. Interestingly enough, there are only very few federal laws in place regarding the non friable materials. Regarding asbestos cement, the visible emission can be relatively easy kept under control by keeping the material wet, which prevents the dust to get airborne. If the material needs to be repaired or replaced, it is recommended to spray it down and keep it continuously wet. Alternatively, the use of HEPA (high efficiency particle arresting) equipment is recommended. Before starting the work and during the project, the material can be kept wet by using a firehouse. The OSHA sets forth a set of regulations for disturbing non-friable materials, which does include frequent inspections, training on operation and maintenance, asbestos awareness training, wet methods and other handling procedures.
If the asbestos cement product will not be subject to disturbance, no further precautions are required, but it is strongly advised to conduct inspections periodically. In general, you may want to consider hiring a licensed asbestos contractor, since the professionals do have all the adequate gear and can make sure, that the project will be done safely.