Laboratory hoods, also known as fume hoods, provide those working with them in scientific or medical fields with an area that can safely contain certain materials for handling, usually because said materials would otherwise constantly be releasing harmful fumes into the air around them. The device pulls all gases under the overhanging transparent hood upward into a ventilation and filtration system designed to screen out the harmful additives in the air and cycle it back into use. This kind of apparatus has become a necessary safety feature in some professions, allowing close work with otherwise unapproachable materials. There are different kinds of fume hoods, but the ones most often used in industrial settings are those with a duct system that can pull airborne contaminants safely away from the user.
For a time the ductwork, liners, and shelves in these hoods often contained the mineral asbestos, which is responsible for causing a long list of serious medical conditions including mesothelioma, a very lethal form of cancer. Primarily transmitted by inhaling small fibers of the substance, asbestos made these hoods dangerous to the health of all those exposed. While a laboratory hood is essential for keeping a workplace healthy, parts of the device made from transite or cement board would repeatedly expose medical and scientific personnel to deadly airborne fibers until the risks became more widely known and asbestos removal began in earnest.
While it’s true that the filter will work safely as long as the asbestos fibers haven’t become frayed or loose, the risks are so serious that older laboratory hoods should not be used under any circumstances. The possibility that an asbestos-containing part of the device has been broken, scratched, or otherwise damaged is all too real, and it only takes a small amount of exposure to this dangerous material to cause serious health problems.