Asbestos in Fume Hoods and Other Lab/Industrial Equipment
Fume hoods, also known as fume cupboards, are pieces of ventilation equipment that are used in laboratories, paint shops and auto repair facilities among other places. These devices are used to protect workers from exposure to potentially toxic dust, gases or other fumes, and even biohazards. A fume hood consists of a box enclosed on five sides with the open side facing the worker. Air is drawn into vents and either expelled outside the building or filtered and recirculated into the room.
Over the years, fume hoods have been lined with various materials, including fiberglass, resin polymers, stainless steel and cement board. The latter was often an asbestos-containing material; the combination of portland cement with asbestos fiber was known as transite. The asbestos fiber made the material stronger and more durable, and as long as it was undamaged, posed little in the way of exposure risk. However, when this material was damaged, it became friable. In this state, asbestos fibers are released as toxic dust into the local environment and may float around an enclosed room for months or years.
Another place where asbestos might have been found is around the electrical equipment that powered the fans. Crocidolite, or "blue" asbestos, was often used as an electrical insulator, since its unique chemical properties made it very useful for this purpose. Crocidolite is one of the most toxic forms of asbestos, known to cause mesothelioma and lung cancer.
The use of asbestos materials in the manufacture of such equipment has largely been phased out since the 1980s, but older units may still contain these materials.
Hazards Associated with Fume Hood Products
The workers producing the transite or the insulating material for the fans in a fume hood might have had some asbestos exposure, as factory workers were often not advised to use appropriate respiratory protection when working with the material.
The fume hoods themselves posed relatively little threat to users when first installed, as the asbestos materials were intact and undamaged. However, as the fume hoods aged, the asbestos insulation in the electrical components and the asbestos cement lining apparatus could easily become friable and begin emitting asbestos fibers that users of the hood could breathe in. Such exposure was quite dangerous and could lead to the development of asbestosis, lung cancer, or mesothelioma.Sources
Bowker, Michael. Fatal Deception: The Untold Story of Asbestos (New York: Touchstone, 2003)