What is Insulation?
Insulation, depending on its application, serves to conserve energy, retain heat or cold, inhibit electrical conductivity or reduce sound volume in a room. Insulation comes in many forms, including blankets, paper sheets and tapes, cloth wraps, cements, plasters, and pre-molded forms. Historically, many types of insulation were made with asbestos because of its properties of heat and flame resistance, chemical stability, moisture and insect resistance, and low electrical conductivity. In the mid 1970's when the connection between asbestos inhalation and asbestos cancer like mesothelioma was discovered, manufacturers stopped using asbestos in their insulation products.
Who Has Worked with Asbestos Insulation?
Tradesmen in many fields may work directly with or around asbestos containing insulation: plumbers, steamfitters, construction workers, workers at power-generating plants, oil refineries, chemical plants and aluminum plants all work with insulation for example. Insulation contractors, manufacturers, insulation distributors and sellers, aerospace workers, demolition workers, and electricians may also handle or work with insulation products. Those who served in the military, especially navy veterans and Naval Shipyard workers were heavily exposed to asbestos insulation throughout their tours of duty as well.
Where is Asbestos Insulation Found?
Asbestos insulation has been used on many types of equipment that are exposed to or generate high heat. Boilers, turbines, and generators run more efficiently when insulated to prevent loss of energy from heat transfer. Steam and hot water pipes, pumps and valves associated with this machinery may also be insulated to prevent loss of heat energy. Asbestos insulation also protects against burns from contact with hot pipes and machinery.
Heating and power-generation machinery can be found in many settings, including residential homes, municipal buildings such as schools or hospitals, and a large range of industrial buildings, from small factories to nuclear power plants.
Commercial Navy ships also use insulation on their heating and propulsion systems. Much of this equipment would be found in the engine and boiler rooms, but insulated steam and hot water pipes may run throughout the ship, including crew sleeping quarters.
Acoustical ceiling tile and panels sometimes contain asbestos as filler. Large office buildings, factories and theaters are likely locations for this product. These panels often conceal electrical and plumbing conduits, and can be removed for maintenance access.
Asbestos is found as part of some types of electrical cable and power cords. The asbestos may be in the form of a fiber braid on the outside of the cord, or as a paper wrap within the inner structure of a cable, or both. Asbestos electrical insulation may be found in combination with cotton, rubber or other types of insulating materials.
Asbestos insulation is also found on spacecraft. Space shuttle nosecones and other parts of the craft incorporate asbestos blankets to protect against the extreme heat of re-entry into the earth's atmosphere.
How Does Insulation-related Asbestos Exposure Occur?
When workers prepare and install new asbestos-containing insulation materials, and remove or disturb old or deteriorated materials, they and others nearby can be exposed to airborne asbestos fibers. Pipe and boiler insulation might consist of pre-formed blocks or half-rounds, which may need to be cut for exact fit. Another type of insulation is the asbestos blanket - several layers of asbestos cloth bound together to form a thick "quilt," which the worker would wrap around a pipe or boiler, often fastening the blanket with asbestos rope laced through grommets at the blanket's edges. Asbestos insulation could also be built up of layers of asbestos cloth and asbestos cement, often several inches thick. The asbestos cement was generally packaged as a dry powder, and mixed with water by the worker. Asbestos cloth came in large rolls from which pieces would be cut as needed.
Asbestos-containing electrical insulation may be exposed when splicing wires or replacing and cutting power cords and cables. Older, cloth-covered appliance power cords may contain asbestos, and fibers may be released from frayed, worn cords.
Repairs and maintenance to pipes, boilers and other machinery may require removal and/or replacement of asbestos insulation. Renovations, remodeling and demolition of buildings may include removal of asbestos insulation. Repairs to electrical and HVAC lines concealed behind acoustical panels may also cause disturbance of fibers.
Common Diseases Associated with Asbestos Exposure
The strong link between asbestos exposure and pulmonary disease did not become common knowledge until the mid-1970's. Workers who have handled asbestos-containing insulation and other workers or supervisory personnel working in the general vicinity, may have inhaled airborne asbestos fibers while on the job. This put them at significant risk for developing one of the following diseases: pleural mesothelioma, peritoneal mesothelioma, asbestos-related lung cancer, pericardial mesothelioma and asbestosis. In addition, workers often brought asbestos fibers home on their clothes which also put their family members at risk for developing one of the above diseases. Those diagnosed with the disease often do not have a favorable mesothelioma prognosis. Even worse, it can sometimes take 30 or 40 years following initial asbestos exposure to develop a disease like mesothelioma.
Some Popular Brands of Insulation
A wide variety of insulation products have been produced over the years. Listed below are some commonly used brands which have at times contained asbestos.
- 85% Magnesia
- Air Cell
- Cafco Blaze-Shield
- Gold Bond
- Red Top
- Super Caltemp
- Super 66