Before the 1980s the construction industry used products that were made from asbestos, including roadboard. It could contain between 20%-80% asbestos. People soon realized that inhaling asbestos was very dangerous. The workers exposed to asbestos did not experience any illness symptoms until about 20 or more years after exposure. Commercial and residential buildings were often constructed using roadboard, a building material that is often formed to look like wooden planks, but can be formed in other shapes, as well.  It was made out of a mixture of natural wood fibers, powder, plastic, and other additives – including asbestos, which made the roadboard more durable and resistant to extreme temperatures.  Since the mineral is mixed into the matrix of the roadboard, it is inert.  However, once the roadboard is damaged in any way, internal asbestos particles can be released into the air. During the earlier part of the 20thcentry, the dangers of asbestos were not widely known. Millions of American employees worked day in and day out around this deadly substance. As the years past, an increased number of people who worked in professions that directly dealt with asbestos products soon developed mesothelioma. In order to protect the public from this hazardous product, the U.S. Occupational Safety and Health Administration (OSHA) stepped in and set limits on what was considered acceptable asbestos exposure.