Wednesday, June 29, 2011

Construction Products that have involved asbestos

Asbestos Caulking and Putties
  Caulking compounds and putties have been widely used in construction projects and plumbing systems since the early 1900s. Both compounds are flexible, semisolid agents used to seal cracks, seams and other gaps in construction. The agents act as a patching material to prevent the leaking of gases, liquids or other fluids between parts.

Uses for Caulking and Putties

  Caulking is an adhesive, sealant material that is typically more heavy duty than putty. Caulk was originally used in the 1930s as a sealing agent to fill seams between planks on ship decks. By filling seams with caulking compounds, ships could be made watertight and airtight. Putty, also called "window putty" or "plumber's putty," is a semisolid compound that is often used to seal window panes and fill holes in surfaces prior to painting.
  Caulking compounds and putties containing asbestos were commonly used as sealants in the following areas:
  • Furnaces
  • Boilers
  • Fireplaces
  • Pipes
  • Stoves
  • Plumbing
  • Ship planks
  • Wall sections
  • Roofing
  • Windows
  • Doors

Asbestos in Caulking and Putties

  Old caulking compounds used for construction and shipbuilding purposes in the early 20th century contained anywhere from 5 to 30 percent asbestos, a mineral now considered hazardous by the U.S. Environmental Protection Agency (EPA). Old roof putties and clay-based putties are believed to have contained 10 to 20 percent asbestos. Asbestos-containing putties were sometimes used in arc lamps and light fixtures to provide protection from heat and fire.
  Asbestos was commonly added to caulking compounds and putties due to its superior heat insulation properties, especially when used in situations involving heated liquids or gases. Long- or short-fiber asbestos could be combined with fillers such as water, linseed oil, white lead, resins, cement or clay to create a pliable, dough-like compound that could be applied to cracks and seams and prevent water damage and heat damage.

Potential Hazards of Asbestos Caulking and Putties

  Caulk and putty that was manufactured or used prior to the 1980s may contain dangerous asbestos fibers. Sealant materials that are cracking, peeling, crumbling or flaking are especially dangerous, as tiny asbestos particles in the compounds may become airborne and cause lung damage, lung cancer, mesothelioma or other cancers if inhaled or ingested.
  While modern-day caulking and putties are typically made using non-asbestos fillers, it is important to be aware of older or damaged sealant materials which may contain asbestos fibers. Asbestos fibers can be released into the air if asbestos caulk or asbestos putty is sanded, ground, scraped, sawed or otherwise disturbed during installation, renovations or construction.

Who May be Affected by Asbestos Exposure from Caulking and Putties

  Individuals at risk for exposure to asbestos-containing caulking and putties include:
  • Renovators
  • Shipbuilders (especially during World War II)
  • Construction workers
  • Window fitters
  • Plumbers

Asbestos Cement, Transite, Cement/Pipes, Furnace/Refractory Cement
  Asbestos cement, or transite, has been used in many cement products throughout the years, with the materials containing as much as 50 percent asbestos.
Transite was first manufactured in 1905 and approximately 1 billion square feet of asbestos cement products were produced by 1950, including many of the following:
  • Pipes
  • Fiber boards
  • Shingles
  • Siding
  • Wallboard
  • HVAC ducts
  • Chimney flues

Cement Pipes

  Asbestos-cement pipes are used in water distribution systems and in general construction. Thousands of miles of asbestos cement pipes have been installed in the U.S. and may not need to be replaced for more than 70 years. Pipes were lined with asbestos cement in the mid-1900s in order to reinforce the pipe and create a smooth pipe interior.  
  Asbestos fibers were mixed with Portland cement and used to coat pipes in order to increase the overall durability of the material. Cement pipes may contain asbestos and have been used in the following construction materials:
  • Gas ventilation
  • Water and sewage distribution
  • Electrical wire conduits
  • Building air ducts
  • Gas heating
  Unless broken, sawed or cut, cement pipes that contain asbestos are not considered to be dangerous. Typically, the asbestos fibers in cement pipes are contained in a wet mixture and the emission of asbestos fibers in this process is considered low. However, if the material is friable, or able to be crushed or pulverized with hand pressure, microscopic asbestos fibers can be released into the air and create a health hazard.
  Asbestos cement pipes that have become corroded over time may soften and lose mechanical strength. As the pipe weakens, asbestos fibers can be released from the pipes and into the water. According to the Environmental Protection Agency, a safe level of asbestos is 7 million fibers or less per liter of water.
  Prolonged exposure to asbestos or high consumption of the fibers in drinking water can increase the risk of cancer and asbestos-related diseases. Plumbers and pipe fitters may also be exposed to asbestos when replacing or repairing pipes.

Cement Siding

  Asbestos-containing cement siding is used to cover the exterior of residential and commercial structures. Asbestos siding may be textured, grooved or smooth and often resembles wood shingles. The siding may be applied to buildings to increase the resistance to fire. Asbestos cement siding was also used to protect against termites, rot and general weathering.
  Asbestos siding is not considered to be a health hazard unless sanded or damaged. Intact siding binds asbestos fibers inside the cement, but if sawed, drilled, chipped or cut, the fibers may become friable.

Furnace and Refractory Cement

  Furnace cement, or stove cement, is a type of joint compound and adhesive that is used in areas exposed to extreme heat. Furnace cement may be applied in the following areas:
  • Boilers
  • Stoves
  • Chimneys
  • Kilns
  • Refractories
  • Manufacturing plants
  Asbestos-containing furnace cement is also resistant to combustible fuels such as oil and coal and helps maintain a safe temperature in the area surrounding boilers and furnaces.  
  Furnace cement that has begun to crumble or break apart can allow asbestos fibers to become airborne. As furnace cement has been used in residential homes and buildings built prior to the 1980s, residents and workers may have been exposed to asbestos fibers.
*  Asbestos Insulation
  Asbestos has been used to provide insulation in a wide variety of products since the 1900s. Asbestos was an attractive material for insulation because it was extremely resistant to high temperatures, and it was also flexible, durable and cost effective. For much of the 20th century, individuals who installed insulation were referred to as "asbestos workers" because they handled the material so frequently.
    While the use of asbestos was gradually phased out in the U.S. in the 1980s due to an increased awareness of the dangers surrounding the substance, asbestos still remains present in insulation in many older homes, commercial buildings and other products.

Common Uses of Asbestos Insulation

  Asbestos has been widely used to provide insulation in the following areas:
  • Homes
  • Industrial buildings (factories, warehouses, etc.)
  • Municipal buildings (schools, hospitals, etc.)
  • Cars
  • Boats and ships
  • Electrical wiring
  • Household appliances (toasters, hair dryers, etc.)
  • Space shuttles
  These are just some of the products that were frequently manufactured with asbestos insulation. The presence of asbestos insulation in such a wide array of products and buildings has placed thousands of individuals at risk of asbestos exposure over the years.

Common Forms of Asbestos Insulation

  Asbestos insulation has been supplied in a number of different forms. Some common forms include:
  • Insulating mix – Insulating mix containing asbestos has been commonly used to provide temperature protection for pipes and other construction products. One of the most commonly-used brands of asbestos insulating mix was HiTemp pipe covering.
  • Insulation coating – Insulation coating containing asbestos was used between the 1930s and the 1970s. Insulation coating is a versatile material that can be used to maintain appropriate temperatures in a wide variety of systems.
  • Insulation ducts – Insulation ducts containing asbestos have been used in the ceilings and the floors of both homes and commercial buildings. Asbestos is generally present on the outer surfaces of the ducts, not specifically in direct contact with the air stream. While the asbestos within insulation ducts does not easily become friable, asbestos fibers can still be released when insulation ducts are renovated or otherwise roughly disturbed.
  • Insulation jacketing – Insulation jacketing containing asbestos has been used to seal insulation over ductwork in a number of manufacturing plants and other environments that are often exposed to high temperatures and high levels of stress. Insulation jacketing is typically self-adhesive and provides protection from harsh weather and other common sources of deterioration.
  • Insulation sealant – Insulation sealant containing asbestos has been used to seal and insulate pipes, duct work and other areas that may be subjected to damage due to harsh weather, high temperatures, moisture and other causes of deterioration. Insulation sealant was typically supplied in a paste-like form that made the substance easy to apply to abnormal surfaces such as the corners or abnormally-shaped areas of a system.
  • Calcium silicate insulation – Calcium silicate insulation containing asbestos was commonly used in pipe lagging. The substance was also used in walls, ceilings and floors. Calcium silicate is made from a number of different minerals and is known for its light-weight nature. Asbestos was commonly added to calcium silicate in order to add sturdiness and fire-resistance.
  Additional forms of asbestos insulation include:
  • Blankets
  • Cements
  • Cloth
  • Paper products
  • Plasters
  • Pre-molded forms

Insulation Brands that Commonly Contained Asbestos

  Asbestos has been used in a wide variety of brand name insulation products over the years. Some of the most common brands include:
  • Air Cell
  • Gold Bond
  • HiTemp
  • Kaylo
  • Limpet
  • Marinite
  • Monokote
  • Superex
  • Super 66
  • Unibestos

Individuals Commonly Affected by Asbestos Insulation Exposure

  Workers in certain occupations that have required the extensive handling of asbestos insulation are generally at a significantly higher risk of asbestos exposure and asbestos-related diseases than other individuals.
  Workers frequently placed at high risk of asbestos insulation exposure include:
  • Insulation contractors
  • Insulation manufacturers and distributors
  • Construction or demolition workers
  • Maintenance workers
  • Plumbers
  • Steamfitters
  • Power plant workers
  • Oil refinery workers
  • Chemical plant and aluminum plant workers
  • Aerospace workers
  • Electricians
  • Members of the military, particularly of the Navy
  In addition to these workers, individuals have often been exposed to asbestos insulation outside of the occupational realm. Many individuals have been exposed to asbestos as the result of contaminated insulation in their home, school or office.
*  Asbestos Roofing Materials
  Roofing materials that contain asbestos have been used in a wide variety of homes and commercial buildings since the early 1900s.
    Two common roofing materials that often contained asbestos include:
  • Roofing shingles
  • Roofing felt
    While the use of asbestos in roofing materials was phased out during the 1980s, many homes, commercial buildings and schools still have roofs made of materials that contain the substance. For this reason, any individuals seeking to make renovations or changes to an older roof should consult a professional first in order to test for the presence of asbestos.

Roofing Shingles

  Asbestos roof shingles were widely used during the 1900s. Asbestos roof shingles typically contain a mixture of asbestos fibers, cement and other additives. The most common form of asbestos roof shingles, known as transite shingles, were composed of asbestos fiber and Portland cement.
  This combination provided protection against problems commonly experienced with wooden roof shingles, such as warping, rotting and insect damage. In addition to these properties, asbestos was also an appealing material for roof shingles because it is fire-resistant, lightweight, durable and inexpensive to manufacture.
  While roofs made with asbestos roof shingles are sometimes referred to as "asbestos roofs," they typically are comprised of less than 30 percent of asbestos.

Roofing Felt

  Roofing felt is a building material composed of heavy paper that has been filled with asphalt. The material is supplied in rolls and is typically delivered in 15-pound increments, although additional weight increments may also be used.
  Asbestos was frequently used as a component of roofing felt, as it added fire-resistance, elasticity and strength to the material. Most asbestos roofing felt was made of approximately 10 to 15 percent of the substance.
  Roofing felt commonly contained chrysotile (white) asbestos, which was typically mined in California, Montana and Quebec. The felt was most commonly used in flat roofs on large commercial buildings but was also occasionally used in pitched roofs and in homes.

Hazards of Roofing Materials

  Roofing materials that contain asbestos and are in good condition generally do not pose serious health risks. However, when asbestos roofing materials have become damaged or deteriorated, they can release harmful asbestos fibers into the air. These microscopic fibers can place individuals in the surrounding area at risk of asbestos exposure and asbestos-related diseases.
  Once asbestos fibers have been released into the air, they can also become attached to the clothing of workers or other nearby individuals. These fibers can then be carried into the home, where additional individuals can be exposed.

Roofing Materials and Mesothelioma

  When asbestos roofing materials have been disturbed and asbestos fibers have been released into the air, they can be unknowingly inhaled or ingested by individuals in the surrounding area.
  Once inside the body, asbestos fibers cannot be broken down. Instead, they can become lodged in tissues surrounding the lungs and the gastrointestinal tract. Over time, the presence of asbestos fibers in these areas can lead to the development of inflammation and, in some cases, the development of a rare cancer known as mesothelioma.

Individuals Affected by Asbestos Roofing Materials

  Roofing materials have commonly placed the following workers at high risk of asbestos exposure:
  • Roofing contractors
  • Maintenance workers
  • Demolition workers
  The materials have also placed other individuals at risk of asbestos exposure. These individuals include:
  • Homeowners
  • Hardware store employees
  Other individuals not listed above may also have been placed at risk of asbestos exposure by contaminated roofing materials.
*  Asbestos Welding Materials
  Asbestos has been used in a variety of welding materials since the early 1900s. Because of this widespread use, workers in the welding industry are some of the most high-risk individuals for asbestos-related diseases.
    Two of the most common welding materials that frequently contained asbestos include:
  • Welding blankets
  • Welding rods
    The use of asbestos in these and other welding materials was discontinued in the United States during the 1980s. However, asbestos is still being used in welding products throughout China, according to the Hong Kong-based watchdog organization known as Aspec.

Welding Blankets

  Welding blankets that contained asbestos were often draped over welders and work surfaces in order to prevent burns or other injuries.
  Asbestos was generally only a single component of the blankets, which were primarily composed of interwoven metal fibers. Because asbestos is extremely fire-repellant, sturdy and flexible, the material served as an integral protective agent in the blankets. This source of immediate protection, however, placed workers at risk of serious long-term consequences.

Welding Rods

  Welding rods that contain asbestos became widely used during the 1930s. The rods were primarily made of metal and were used to provide filler material during the welding process. They were usually two to three feet in length.
  These welding rods commonly contained large amounts of amphibole asbestos of the crocidolite (blue) variety. While welding rods today are used to conduct current during arc welding, asbestos was particularly appealing to manufacturers of welding rods during the mid-1900s because it was a strong resister of electric current.

Hazards of Welding Blankets and Rods

  Because welding rods and blankets that contained asbestos were often placed in direct, close physical contact with individuals, the products often posed serious health risks. While asbestos generally is not a health hazard when left undisturbed, welding products that contained the substance were often subjected to a significant amount of wear and tear.
  When cut, weathered or otherwise damaged, welding products released harmful microscopic asbestos fibers into the air. Even a small tear at the seam of a welding blanket could prompt the release of millions of microscopic asbestos fibers. The release of these harmful fibers placed all surrounding individuals, and especially those in close contact with the welding materials, at risk of developing serious asbestos-related diseases.
  Asbestos fibers released during welding processes could also attach to the clothing of workers and be carried into the home, placing family members and other individuals at risk of asbestos exposure.

Welding Materials and Specific Cases of Asbestos Exposure

  Welding rods were first directly linked by a jury to individual cases of asbestos-related diseases in 2003, when welding rods used in a workplace were connected to the development of mesothelioma and lung cancer. This influential case opened the door for future cases directly linking occurrences of asbestos-related diseases with welding products.
*  Asbestos Brick, Block Mortar, Masonry Fill & Bonding Cement
  Asbestos, a mineral commonly used for its ability to withstand extreme temperatures and fire, was found in numerous products up until the 1980s. In 1977, the use of asbestos was banned by the Consumer Product Safety Commission due to serious health and safety concerns, but asbestos-containing products are still present in homes and commercial properties today.
    Three products used in the bonding and insulation of blocks and brick that are known to have contained asbestos include brick and block mortar, masonry fill and bonding cement.

Brick and Block Mortar

  Brick and block mortar, or the workable paste that binds blocks and brick together, often contained between 80 and 95 percent asbestos before 1980, placing those who worked with or around the mortar in danger of exposure to toxic asbestos fibers. Mortar becomes very hard once it sets and was used to seal cracks and crevasses and bind construction bricks together. Asbestos was often added to the mix to increase the strength and fire-resistant properties of the mortar.

Masonry Fill

  Like brick and block mortar, masonry fill was used between blocks. Poured in between cinder blocks to produce extra insulation, masonry fill commonly contained asbestos due to the mineral's durability and heat-resistant properties.

Bonding Cement

  Bonding cement is used for a variety of purposes. Often used as a coating for insulation and a base coat for stucco and decorative wall finishes, bonding cement was used in both load-bearing and non-load-bearing walls. The bonding cement used prior to 1980 often contained as much as 15 percent asbestos, placing those who came in contact with bonding cement at risk of asbestos exposure.  

Hazards of Brick and Block Mortar, Masonry Fill and Bonding Cement

  Brick and block mortar, masonry fill and bonding cement made with asbestos can be very dangerous when disturbed. This often occurs due to:
  • Typical corrosion
  • Renovations
  • Additions to homes or buildings
  • Maintenance of buildings
  • Pressure cleaning
  • Weather
  • Demolition
  The disturbance of the asbestos-tainted products can generate dust containing tiny asbestos fibers which enter the air. Individuals nearby may then inhale or ingest the toxic fibers. If the tiny asbestos fibers are inhaled or ingested, they can become lodged inside the body. Once there, the fibers can cause irritation and inflammation, which, over time, may cause serious health conditions to develop.
  Inhaling or ingesting asbestos fibers may lead to a variety of health complications, including asbestosis or mesothelioma, a rare cancer that typically affects the lining of the lungs. Mesothelioma may also affect the heart, abdomen and, very rarely, the testicles.
*  Asbestos Joint Compound & Dry Mix Joint Compound
  Joint compound, or drywall compound, is a white substance that is used to seal joints between sheets of drywall during building construction. This product is available as a pre-mixed paste that may be applied immediately and a dry mix powder that is combined with water at the construction site.  Joint compound products that were manufactured before 1978 commonly contained asbestos fibers due to its resistance to heat, moisture and insects.

Uses of Joint Compound

  Joint compound may be used to fill cracks, smooth rough spots, patch holes in plaster or drywall and seal pipes and joints. This product may be used to remove or conceal imperfections in walls, such as:
  • Drilled-in screws
  • Hanging tape
  • Drywall tape
  Joint compound may also be used as a finish on the following surfaces:
  • Panel joints
  • Trim
  • Fasteners
  • Wallboard
  • Ceilings
  • Drywall
  Asbestos joint compound may improve the working texture of the surface where it is applied and is used during new construction and remodeling of older homes. This product has been found to contain 5 percent or less asbestos.

Dangers of Joint Compound

  Dry mix asbestos joint compound is mixed with water on-site during construction or renovation and can create a large amount of dust.  The dust created from the application or removal of joint compound may contain asbestos fibers.
  After application, both the dry mix powder and the ready-mix paste dry in hours. Several coats of joint compound may be needed, and after each new coat, the dried product is sanded down before new applications to create an even, smooth surface. This process creates a seamless area between drywall boards and a smooth texture over the drywall flaws.
  Pole sanding and hand sanding of the joint compound may release asbestos fibers that were contained in the joint compound into the air. Sanding may create approximately 5.3 million to 10 million asbestos fibers per cubic meter of air.
  Cleaning and sweeping excess dust and debris after sanding or grinding may re-emit asbestos fibers into the air. Those living or working nearby may also have been exposed to asbestos dust. Asbestos joint compound that is in good condition may not pose a health risk, but joint compound that has worn down and begun to disintegrate can emit asbestos fibers into the air.
  The inhalation and ingestion of asbestos fibers that have been emitted from joint compound may cause serious health conditions. Once the fibers have entered the body, they may lodge in the lining of the lungs, abdomen or heart. The prolonged irritation of the organ lining may result in the development of mesothelioma and other asbestos-related diseases years later.
*  Asbestos Textured Coatings & Paints
  Textured products that contain asbestos were widely used in homes and commercial buildings during the mid-1900s. Two commonly used textured products containing asbestos include:
  • Textured coatings
  • Textured paints
    While the use of asbestos in these products was phased out during the 1980s, textured coatings and paints that contain asbestos are still present in a number of older homes and buildings. For this reason, individuals seeking to make renovations or changes to buildings or homes that contain textured coatings or paints should seek professional assistance first to test for the presence of asbestos.

Uses of Asbestos in Coatings and Paints

  Textured coatings that contain asbestos were used for a variety of decorative and protective purposes. They were frequently used to conceal or diminish construction flaws on ceilings or other common household surfaces. Asbestos was an appealing material for textured coatings because it provided a unique combination of strength, flexibility and insulation.
  Textured coatings and paints were generally made with only a small amount of asbestos, and most were typically composed of less than 10 percent of the substance. While this percentage is less than the asbestos component of many other construction materials, textured asbestos coatings and paints have still placed individuals at risk of asbestos exposure.

Brand Names of Textured Asbestos Products

  Common brand name textured coating and paint products that have been produced with asbestos in the past include:
  • Artex
  • Marblecoat
  • Newtex
  • Pebblecoat
  • Suretex
  • Wondertex

Hazards of Textured Coatings and Paints

  When textured coatings and paints are in good condition and left untouched, they generally do not pose a health concern. However, when the products are sanded down, weathered or otherwise tampered with, they can deteriorate to the point where they become friable, meaning they can crumble easily.
  When this happens, the products can release harmful microscopic asbestos fibers into the air, which then places individuals in the surrounding area at risk of asbestos exposure and asbestos-related diseases. These fibers may also collect on a nearby individual's clothing, leading them to be carried into other homes or buildings, where additional people may be placed at risk of exposure.
  Recent studies have suggested that the risks of asbestos exposure from textured coatings and paints are lower than previously thought. However, because the products still contain asbestos, they do still pose health hazards. Also, in many cases, textured coatings or paints that contain asbestos were used to cover other construction materials that contain asbestos, such as asbestos insulating board.
  When textured coatings or paints release harmful asbestos fibers into the air, these fibers can be inhaled or ingested by individuals in the nearby area. Once in the body, asbestos fibers can lead to the development of inflammation over time. In some cases, their presence can eventually lead to the development of a rare cancer known as mesothelioma.

Individuals Affected by Textured Coatings & Paints

  Textured products containing asbestos have commonly placed the following workers at high risk of exposure:
  • Painters
  • Construction workers
  • Maintenance workers
  • Demolition crews
  The materials have also placed other individuals at risk of asbestos exposure. These individuals include, but are not limited to, the following:
  • Homeowners
  • Students
  • Office workers
  • Hardware store employees
  Any individuals located in areas where asbestos fibers have been released into the air from textured coatings or paints are at risk of hazardous exposure to the substance.
*  Vermiculite Compounds
  Vermiculite is a naturally-occurring, metamorphic mineral belonging to the mica group of silicate minerals. Similar to the mineral asbestos, vermiculite is mined from raw ore deposits and processed worldwide for various industrial and construction products. In raw form, vermiculite may appear as shiny flakes. When processed, the mineral can be silver-gold, tan, green or gray-brown.
    Vermiculite is mainly used in its processed form, after the mineral has been heated through a process known as exfoliation, or "popping." When rapidly heated, vermiculite transforms and recrystallizes due to a layer of water molecules contained within its structure. The water molecules are converted to steam and cause the mineral to expand to as much as 30 times its original size. This expanded form of vermiculite is lightweight, absorbent and a good insulator from heat and fire.

Asbestos in Vermiculite Compounds

  Unfortunately, vermiculite mines can be sources of other minerals, too. Many vermiculite mines have been found to contain naturally-occurring asbestos. Vermiculite that has been contaminated with asbestos poses a significant health hazard to people who are exposed to airborne asbestos particles during any part of the mining or production processes, or to those who live near vermiculite mines or factories. While some asbestos-containing vermiculite mines have been shut down in recent years, many vermiculite products that contain asbestos are still in use today.

Uses for Vermiculite Compounds

  Over the last century, vermiculite has been widely mined and processed worldwide for various construction, industrial and horticultural applications, as it is a superior insulator and filler material that is both lightweight and inexpensive.
  Vermiculite has been used for the following applications:
  • Fertilizer carrier
  • Potting soil additive
  • Soil conditioner
  • Attic insulation (loose-fill, commonly sold under the product name Zonolite)
  • Acoustic finishes
  • Spray-on insulation
  • Concrete mixes for swimming pools
  • Stucco
  • Alternative to gypsum wallboard
  • Plasterboard
  • Packaging material (similar to styrofoam peanuts)
  • Fireproofing material
  • Whitewashes

Potential Hazards of Vermiculite

  While vermiculite itself is not hazardous, the presence of other minerals such as asbestos or asbestos-like fibers in vermiculite compounds can pose a significant health hazard. The U.S. Environmental Protection Agency (EPA) and other regulatory agencies have discovered that certain vermiculite ore deposits in the U.S. may contain tremolite, actinolite or other types of asbestos fibers. The Agency for Toxic Substances and Disease Registry (ATSDR) has linked exposure to asbestos in vermiculite with adverse health effects such as lung disease, asbestosis and mesothelioma.
  Asbestos fibers can be released from vermiculite during any stage of the mining, exfoliation or shipping processes, but the greatest danger is thought to exist during the exfoliation and processing step. When vermiculite is heated and expanded, asbestos fibers can be rapidly released into the air. If asbestos fibers are inhaled or ingested over long periods of time, the fibers can lodge in body tissues and remain in the body for many decades, causing serious health complications in later life.
  Additionally, some vermiculite products may contain asbestos and pose a health hazard when used. For example, products such as vermiculite potting soil and gardening materials have been found to contain small amounts of asbestos during routine sampling tests by the EPA. If the asbestos fibers are loosened or otherwise disturbed, the fibers can easily become airborne.

Locations of Vermiculite Mines and Processing Plants

  Vermiculite is mined worldwide, but the biggest producers of vermiculite today include the United States, South Africa, China, Japan and Russia. In the U.S., the largest vermiculite mines are found in South Carolina (Enoree and Woodruff), Virginia (Louisa County) and Montana (Libby, now closed). In 1998, there were as many as 20 vermiculite exfoliating plants in 11 states in the U.S.
  Prior to 1990, more than 70 percent of the world's vermiculite was mined from Zonolite Mountain in Libby, Montana. The Libby mine operated from 1923 until 1990, when it was shut down due to the discovery of large amounts of asbestos in the mines. A 1984 study showed that raw vermiculite from Libby mines contained on average 3.5 to 6.4 percent asbestos by weight. When Libby vermiculite was actively being mined and processed, air quality reports for the downtown Libby area show that airborne asbestos fiber concentrations were up to 15 times the current safety limit.
  Asbestos-containing vermiculite from the Libby mines was shipped around the U.S. to be processed and exfoliated. Processing sites where the contaminated vermiculite was shipped include:
  • Beltsville, MD
  • Dallas, TX
  • Dearborn, MI
  • Denver, CO
  • Easthampton, MA
  • Edgewater, NJ
  • Ellwood City, PA
  • Glendale, AZ
  • Hamilton Township, NJ
  • Honolulu, HI
  • Los Angeles, CA
  • Marysville, OH
  • Minneapolis, MN
  • Minot, ND
  • New Castle, PA
  • New Orleans, LA
  • Newark, CA
  • Omaha, NE
  • Phoenix, AZ
  • Portland, OR (N. Harding and N. Suttle)
  • Santa Ana, CA
  • Spokane, WA
  • St. Louis, MO
  • Tampa, FL
  • Trenton, NJ
  • Weedsport, NY
  • West Chicago, IL
  • Wilder, KY

Who May be at Risk for Asbestos Exposure

  Those at highest risk for asbestos-related diseases from vermiculite exposure include individuals who worked in the vermiculite mines in Libby, Montana, for W.R. Grace and those who worked in processing plants where vermiculite was ground into powder or exfoliated. Vermiculite workers involved in the following processes may have been exposed to asbestos:
  • Mining
  • Milling
  • Exfoliating
  • Handling
  • Shipping
  Individuals who lived with workers involved in the above-mentioned processes may also have been exposed to asbestos, as the fibers are easily carried home in hair, on clothing or on shoes. Residents who lived within the vicinity of vermiculite mines or vermiculite manufacturing sites may have been exposed to asbestos through the air.
  Other occupations which may have been affected by asbestos-containing vermiculite include:
  • Construction workers
  • Demolition crews or remodelers
  • Homeowners

*  Asbestos Corkboard, Cork-Covering & Cork-filled Mastic
  Cork board is a construction material that may be used in homes and other structures and may be applied to the following areas:
  • Flooring
  • Insulation
  • Wall covering
  • Sealant
  • Covering for gear cases and other devices
    Cork is highly flexible, buoyant and fire resistant and can be combined with other construction materials such as rubber or resin.
    Sheets of cork are often used as building materials, as it is an effective insulation material. During the 1970s, asbestos fibers were used to strengthen cork materials due to its ability to withstand high temperatures.

Cork Board and Cork-Covering

  Cork board is a low-density, elastic material that is commonly used in construction in residential homes and commercial buildings. Cork boards may be placed under floor tiles and in walls as a fire prevention measure and as a way to sound-proof rooms. The spongy material of cork helps absorb sound and reduce noise levels.
  Cork-covering is a type of decorative covering that may be applied to walls and ceilings. This material may also be used in industrial settings as a type of insulation around pipes, cover plates for washing machines and gear cases.
  Cork board sheets and coverings that are disturbed during installation or building renovation may emit asbestos fibers. Tearing, moving or damaging asbestos-containing cork boards may release fibers from the cork, exposing construction workers, homeowners or anyone nearby to asbestos that can be breathed in or inhaled.

Cork-Filled Mastic

  Asbestos cork-filled mastic is a paste-like cement that contains graded cork, mineral fillers and asbestos fibers and may be used as an adhesive during construction. This product is often applied as an insulation material that protects pipes used in cooling industries such as refrigeration.
  Cork-filled mastic may be applied to the following surfaces:
  • Metal tanks
  • Air ducts
  • Pipe lines
  • Pipe ducts
  The material also helps prevent the build-up of moisture on pipes due to low thermal conductivity.
  The product may be applied using a trowel, hand or mastic spray equipment, and during the application of cork-filled mastic, asbestos fibers may easily become airborne. Construction workers and those nearby may be exposed to asbestos.

Cork Products and Mesothelioma

  Released asbestos fibers that have become airborne may be inhaled or ingested by those near the asbestos-containing product. Once in the body, the fibers may become lodged in the mesothelium, or the thin membrane lining the internal organs. The fibers cannot be displaced from the membrane and can cause inflammation and irritation in the mesothelium, which may result in severe health conditions including mesothelioma and asbestosis.
*  Ehret Asbestos Block & Pipe Covering
  The Ehret Magnesia Manufacturing Corporation, located in the industrial village of Port Kennedy (now called Valley Forge), Pennsylvania, produced many asbestos-containing insulation products from the mid-1890s until the 1970s.
    The company produced Ehret block insulation and Ehret pipe covering to be used in the following situations where pipe insulation was needed:
  • Steam pipes
  • Boilers
  • Furnaces
  • Hot water heaters
  • Factories
  • Steam rooms
  • Ships
  • Power plants
  • Heating, ventilating and air conditioning systems (HVAC)
    Prior to and during World War I, Ehret block insulation and pipe covering were widely used by the U.S. Navy to help conserve fuel and reduce costs on military vessels. Block and pipe covering helped to reduce fuel consumption by preventing the unwanted transfer of heat and steam from pipes, as well as providing reinforcement to prevent pipes from cracking under high temperatures.

Asbestos in Ehret Block and Ehret Pipe Covering

  To minimize heat loss from steam pipes and reduce unwanted heat transfer in boilers, evaporators and turbines, Ehret developed insulating products made of asbestos and magnesia that could be molded to fit around hot pipes. Ehret products were often referred to as "85% Magnesia," as the products contained 85 percent magnesia, a product derived from magnesium carbonate and calcium. Magnesia was known for its superior heat insulation properties and ability to withstand high temperatures and prevent fires, and long-fibered asbestos was added as a binder material to the compounds to add structural reinforcement.

Ehret Block

  Ehret 85% Magnesia was often supplied as preformed blocks of insulation, which could be used to support and insulate pipes. The Ehret block insulation was typically made of at least 10 to 15 percent asbestos and magnesia and was sold under various brand names such as "Thermalite Block Insulation" until the 1960s.
Preformed, or molded, asbestos block insulation used on boilers and hot water heaters was banned in 1975 by the U.S. Environmental Protection Agency (EPA), based on regulations set forth by the National Emission Standards for Hazardous Air Pollutants (NESHAP) and the Clean Air Act.

Ehret Pipe Covering

  Ehret pipe covering was similar to Ehret block and was sold under various brand names, including "Thermalite Pipe Covering," until the 1970s. Pipe covering made with asbestos may appear white or chalky and is typically wrapped with a thin canvas material. The Ehret pipe covering can be found around steam pipes and is known to be very lightweight. It is thought that Ehret pipe coverings were manufactured at the Pennsylvania factory until the 1990s.

Dangers Associated with Ehret Block and Ehret Pipe Covering

  Ehret block insulation and Ehret pipe covering are known to contain asbestos fibers, which can pose a serious health hazard if inhaled or ingested. If asbestos-containing block insulation or pipe covering is damaged, sanded, sawed or otherwise disturbed, the microscopic asbestos fibers can become airborne, where they can be easily inhaled or ingested. Insulation or pipe covering that appears dry, crumbling, pulverized, flaking or powdered should not be touched.
  Individuals who may have been exposed to asbestos fibers found in Ehret block and Ehret pipe covering include:
  • Ehret factory workers
  • Insulation workers or installers
  • Renovators or demolition workers
  • Pipe fitters
  • Plumbers
  • Shipbuilders
  The 85% Magnesia Ehret block and pipe covering are particularly dangerous because the products often required sanding or sawing in order for the insulation to be fitted to pipe shapes.
*  Asbestos Ductwork Connectors & Flexible Duct Connectors
  Ducts are used to circulate air through a system of pipes and channels in homes or buildings. This air system is used in heating, ventilation and air conditioning. Ductwork connectors are inserted in between ductwork and other machinery and reduce vibration and noise within the duct system.
    Asbestos materials may be contained in the following types of ductwork material:
  • Metal
  • Vinyl
  • Plastic
  • Corrugated paper
  • Fiberglass
  • Flexible ducting
    Ductwork connectors were often made with asbestos fibers during the mid-1940s and 1950s. Asbestos fibers that have been emitted into air may cause health hazards in those who have been exposed.

Ductwork Connectors and Flexible Ductwork Connector

  Some asbestos-containing ductwork is comprised of pipes and metal ductwork made with asbestos fibers, and certain sections of ductwork may also be wrapped in cellulose asbestos or air-cell insulation. Duct systems are often located in the following building spaces:
  • Attic
  • Attached garage
  • Floor cavity
  • Crawl space
  • Unheated basement
  • Drop-down ceilings
  • Mechanical rooms
  • Vertical chases
  Flexible ductwork connectors are thin strips of flexible material and are designed to fit into ductwork of varying sizes. This product is typically made of a fabric such as canvas and is installed between duct fans to reduce rattling that may occur in the ventilation and air system. Flexible ductwork connectors may also be applied in high to low pressure conditions.
  If ductwork or the ductwork connectors are cut, repaired, installed or disturbed in other ways, asbestos fibers may be released into the air. Asbestos ductwork or wrapping that has worn down over time due to heat or age may allow fibers to become friable, or easily crumbled into dust or small particles.
  Once airborne, the asbestos fibers may be easily circulated throughout a building or home by way of the ductwork system. Contractors, workers, homeowners or those who work in buildings with asbestos ductwork may be exposed to asbestos.

Removing Asbestos Ductwork or Flexible Connectors

  Homeowners who think their home may contain asbestos ductwork may perform the following to remove the duct connectors:
  • Take a sample from the ducts and send for testing
  • Use the required safety equipment
  • Enclose the area thought to have asbestos materials
  • Contain asbestos materials in proper disposal bags
  Many people choose to hire asbestos abatement experts to help remove asbestos materials.  Only certified, licensed asbestos experts may be permitted to remove asbestos ductwork or flexible ductwork connectors.

Ductwork and Mesothelioma

  Airborne asbestos fibers emitted from worn out or cut ductwork may be inhaled or ingested and may become caught in the thin lining of the organs. Once in the body, the fibers may not be dislodged and may cause irritation and inflammation. Prolonged irritation may cause serious health conditions such as mesothelioma.
* Asbestos Patching Fiber, Patching Plaster & Wood Fiber Plaster
  Commonly used in building construction and home repairs, patching compounds can be applied to ceilings, walls, drywall and other surfaces to seal cracks and cover holes. Patching fiber, patching plaster and wood fiber plaster are typically supplied in a dry, powdered form to be mixed with water before use. The powder forms a spreadable paste that hardens after drying. Other types of patching compounds are supplied as a ready-mix paste.
    Patching plasters can be made from various ingredients, including talc, clay, ground stone, mica, pigments and binding materials such as asbestos fibers. Asbestos was often added to patching fiber and patching plaster made prior to the 1980s, as asbestos fibers could provide structural reinforcement to help reduce cracking and shrinkage of the plaster compound over time. Asbestos-containing patching plasters were valued for their ability to insulate from fire and heat while still being lightweight.

Asbestos in Patching Fiber & Patching Plaster

  Patching fiber and patching plaster, sometimes called asbestos patching cement, is used to patch holes, seal cracks and fill gaps in walls and ceilings. The compounds are typically white in color and are commonly used in building and home construction.
  Patching fiber and patching plaster that contains asbestos filler can be dangerous, especially if the dry powder is inhaled during stirring and mixing. After the product has dried, asbestos fibers can be released into the air when the patching plaster is sanded, smoothed, scraped or drilled. If patching fiber or plaster is flaky or damaged ("friable"), asbestos fibers can be released into the air if the compound is disturbed.
  Patching compounds manufactured prior to the 1980s have been found to contain 5 to 25 percent asbestos.

Wood Fiber Plaster

  To reinforce strength and durability, wood fiber was sometimes added to plaster compounds. Wood fiber plaster compounds were frequently used on various surfaces including:
  • Concrete
  • Wood
  • Metal
  • Plaster board
  • Gypsum
  • Tile
  Unfortunately, many wood fiber plaster compounds contained asbestos fibers in addition to cellulose (wood) fibers. The plaster was often spread on walls and ceilings to provide insulation, fire protection or decorative finishes.

EPA Ban of Consumer Patching Plaster & Patching Fiber

  In December 1977, the U.S. Environmental Protection Agency (EPA) issued a ban affecting all consumer patching compounds containing intentionally-added, "free-form" asbestos fibers. Chrysotile asbestos fibers were often present in patching fiber and patching plasters manufactured prior to the EPA ban, which created a significant health hazard.
  Free-form asbestos, or asbestos that can easily detach from bonding compounds and become airborne, can be dangerous if inhaled or ingested by consumers.
  According to the U.S. Consumer Product Safety Commission, half of all patching compounds distributed in 1977, prior to the ban, contained asbestos fibers, even if asbestos was not included on the list of ingredients.

Occupations At Risk for Asbestos Exposure

  Individuals who worked in the following industries may have been exposed to asbestos in patching fiber, patching plaster or wood fiber plaster:
  • Carpenters
  • Construction workers
  • Homeowners
  • Renovators
  • Repairmen
  • Drywall tapers
  • Plasterers
  • Plaster factory workers

*  Asbestos Acoustical Plaster, Decorative Plaster, Acoustic Finishes & Troweled Coating
  Plaster and acoustical finishes are products used to cover cracks or blemishes in walls and ceilings and absorb sound. Decorative plaster, or acoustical plaster, and troweled coatings are used to add ornamental design to surfaces. Asbestos was commonly used as an insulation material in the mid-1900s, and plaster materials may contain asbestos fibers.

Acoustical Plaster and Acoustical Finishes

  Acoustical plaster and finishes are a mixture of asbestos fibers, water, lime and sand and are often applied inside homes or commercial buildings on walls, ceilings and pillars. These products may contain asbestos if manufactured before 1981.
  Troweled coatings are a type of decorative plaster that has been commonly used as a surface texture known as "popcorn" ceilings, or a bumpy ceiling that resembles cottage-cheese. Scraping or performing repair work on popcorn ceilings may create asbestos dust that can cause asbestos fibers to become airborne.
  Acoustical plaster products have been used in the following structures:
  • Schools
  • Residential homes
  • Commercial buildings
  • Libraries
  • Theaters
  • Offices
  The presence of asbestos in acoustical plaster and finishes cannot be identified by looking at the materials. Samples of the ceiling may be taken and sent to laboratories to test for asbestos.
  Applying and removing acoustical plaster and finishes may cause asbestos exposure as the fibers may float in the air. Plaster may also become worn down over time and can crack or break apart. Asbestos fibers may be expelled into the air if plaster is broken into small particles or dust through hand pressure.

Removing Acoustical Plaster Products

  Removing asbestos plaster products may disturb asbestos and allow the fibers to become airborne, exposing homeowners and construction workers to asbestos. The following may disturb asbestos-containing materials:
  • Sanding
  • Grinding
  • Breaking apart acoustical ceilings or walls
  • Sawing
  • Drilling
  • Smoothing rough edges
  • Renovation in other areas of the home or building
  Certified, asbestos abatement contractors are often hired to remove asbestos due to the hazards associated with the material.
  Contractors typically build a containment area in order to limit the area where asbestos fibers may settle. The acoustical plaster should be disposed of in regulation bags and thrown away in an approved asbestos disposal site.
*  Asbestos Flat Board, Millboard, Panels & Cement Wall Board
  Asbestos flat board, millboard, panels and cement wall board are construction materials used to insulate residential homes and commercial buildings. These products are typically used in high-temperature areas such as furnaces and fireplaces or in ceilings and walls during building construction. Asbestos was commonly used in manufacturing these products as asbestos fibers are strong and resistant to heat and abrasion.

Asbestos Millboard and Panels

  Millboard and panels are made of compressed fibers and may be used as insulation in the following industries:
  • Metal molding
  • Foundries
  • Kilns
  • Glass manufacturing
  This material may also be found in boilers, stoves and ovens as fire and heat protection. Millboard or flat board that are cut, torn or ripped may allow asbestos exposure to occur through the presence of airborne asbestos fibers.
  During the installation of asbestos millboard or panels, construction workers may have been exposed to asbestos fibers. Renovation projects that require drilling or tearing of these materials can also release asbestos fibers into the air. Asbestos millboard may contain up to 85 percent asbestos and was used commonly during the early 1900s.

Cement Wall Board and Flat Board

  Cement wall board, or cement drywall, is a popular construction material that is applied to interior walls in homes or commercial buildings, and flat board is a reinforced cement board used to provide a smooth outer finish. Cement board products are resistant to fire and corrosion, as they are coated with asbestos-containing cement.
  Asbestos cement consists of Portland cement that has been reinforced with asbestos fibers. The cement was developed in 1905 and is used to coat wall board, flat board and other construction products.
  Many homes built during the early 1900s were constructed with cement board products. The wall board or flat board may be fitted to walls in sheets without the use of plaster or mortar.
  Types of cement boards include:
  • Flat transite
  • Asbestocite A
  • Standard asbestos flexboard
  • Perforated marine veneer
  These products were used to fireproof rooms and were placed indoors as a wall finish in areas that were exposed to extreme heat such as:
  • Chimneys
  • Dormer windows
  • Skylights
  • Shingles
  • Walls
  • Ceilings
  • Protecting beams
  • Posts
  These materials may wear down over time and allow fibers to escape from the bound wall board and flat board. Exposure to the fibers that make up asbestos may occur if the cement board materials are broken or damaged.
  Construction workers who cut, sanded, installed, shaped and drilled the cement wall board and flat board may also have been exposed to asbestos.

Asbestos Board Products and Mesothelioma

  Fibers that have been expelled into the air from construction work or from damaged asbestos board materials can be breathed in or swallowed. Once in the body, the fibers can become stuck in the thin membrane that covers the lungs. This condition is known as mesothelioma and is characterized by the inflammation and irritation of the lining of the lungs.
*  Asbestos Spray-Applied Insulation & Thermal Spray
  Spray-applied insulation and thermal spray is commonly used to cover irregular or flat surfaces with an insulating material. Often applied to the "dead" spaces within commercial buildings, ships, automobiles, trains, power plants, residential homes and other structures, spray-applied insulation is a relatively simple and inexpensive solution for providing lightweight, thermal and acoustical insulation in attics, on steel beams, behind walls, above ceilings and in other spaces.
    Spray-applied insulation is also used for decorative purposes, such as with "popcorn" ceilings which were a popular addition to the ceilings of residential homes from the mid-1960s until the late 1970s.

Asbestos in Spray-Applied Insulation & Thermal Sprays

  Typically appearing as a white, fluffy material, spray-on insulation and thermal spray often contained asbestos from the 1930s until the 1970s. Known for its superior ability to insulate from fire and heat while still being lightweight, asbestos fibers were commonly used as spray-applied insulation and thermal spray within buildings to provide fireproofing and structural insulating.

Sprayed Limpet Asbestos

  One of the most well-known brands of spray-applied insulation used in the 20th century was Limpet asbestos. Actively used from 1932 until 1973, Limpet asbestos was typically manufactured with crocidolite asbestos, one of the six primary types of asbestos fibers, by the company J.W. Roberts Limited.
  Limpet and other types of spray-applied insulation were applied to surfaces using a spray gun machine, which used compressed air to mix asbestos fibers with water or rubber as the adhesive material was sprayed.
  Limpet asbestos was often applied to ceilings, walls and support beams of railway coaches, ships, office buildings and other locations during this time, until spray-applied asbestos insulation was banned by the U.S. Environmental Protection Agency (EPA) in 1973. The November 1990 revision of the National Emission Standards for Hazardous Air Pollutants (NESHAP) policy also prohibited the use of spray-on materials containing more than 1 percent asbestos.

Hazards of Asbestos Spray-Applied Insulation & Thermal Sprays

  Spray-on asbestos is now considered to be one of the most dangerous forms of asbestos, as compared with the other uses of asbestos in the construction industry. During both the application process and when the material is disturbed or removed, spray-applied asbestos produces millions of microscopic, airborne asbestos fibers which can be dangerous and carcinogenic if inhaled or ingested.
  Individuals who may have been exposed to asbestos in spray-applied insulation and thermal spray include:
  • Construction workers
  • Insulation workers
  • Electricians
  • Building maintenance workers
  • Plasterers
  • Sheet metal workers
  • Spray operators
  Buildings and structures built before 1970 have a high change of containing asbestos insulation.
  Airborne asbestos fibers are estimated to remain in the air for 4 to 20 hours if damaged or touched, depending on the fiber diameter, fiber length and surrounding air currents.
*  Asbestos Lap Siding
  Lap siding, also referred to as clapboard siding, is widely used in home construction as an exterior covering to provide visual appeal as well as to protect structures from weather damage, termites, rodents, dirt, smoke, excessive sunlight and other environmental factors. Lap siding is characterized by a horizontal pattern of repeating boards or shingles in which the higher rows overlap the lower rows.
    From the 1940s until the 1970s, lap siding was often manufactured using asbestos in the U.S. and in Europe. In many cases, asbestos lap siding, also known as asbestos-cement siding, was considered to be the lowest-maintenance, longest-lasting siding available. Asbestos lap siding has since been replaced by fiber-cement siding, as exposure to asbestos fibers has been linked to a myriad of health conditions, including lung cancer and mesothelioma.

Identifying Asbestos Lap Siding

    Asbestos lap siding was manufactured with a light concrete, often portland cement, that was then reinforced with asbestos fibers. The mixture was pressed into thin, wide sheets and then cut into shingles or boards. Asbestos lap siding can be identified by the following characteristics, which may be visible in some cases:
  • Wavy bottom edge
  • Wood-like grain pattern
  • Bright white color
  • Corrugated grooves in the surface
    Overlapping shingles or boards containing asbestos were used widely in home and building construction in the mid-20th century. The asbestos siding could be applied directly to the studs and framework of a building or applied over a layer of sheathing (which often contained asbestos).
    Asbestos lap siding was prized for its fire-resistant and noncombustible properties, as well as its durability and resistance to rot and moisture. However, asbestos lap siding boards have also been known to be brittle, thin and easily broken.

Potential Dangers of Asbestos Lap Siding

  While most asbestos lap siding is relatively harmless if left undisturbed, the material is unfortunately very brittle and easily broken, which can release asbestos fibers into the air.
  Asbestos fibers in lap siding normally remain encapsulated by cement, but if the lap siding is sanded, cut, drilled or broken, the material can crumble and release asbestos powder. Asbestos may also be released into the air if asbestos lap siding is removed or otherwise disturbed by renovators or construction workers.
  Airborne asbestos fibers pose a serious health hazard if the fibers are inhaled or ingested by people nearby. The fibers can lodge in lung tissue, where they can remain for many years and lead to health complications such as asbestosis, lung inflammation, lung scarring, as well as mesothelioma, lung cancer and other cancers.
  Lap siding products known to have contained asbestos include Gold Bond Asbestos Siding manufactured by the National Gypsum Company.
Asbestos Duplex Block, Duplex Pipe Covering, Pipe Covering and Air Cell Pipe Covering
  Block insulation, pipe covering and air cell pipe covering are types of insulation used around concrete blocks, pipes, and boilers. Insulation may be applied in residential homes and commercial buildings to protect the structure from extreme temperatures.
    Asbestos was added to insulation materials as asbestos fibers are durable and naturally resistant to heat, chemicals and other abrasive substances.

Block Insulation

  Block insulation may be applied to concrete blocks that support houses, apartments and other structures. This material may also be used in the following industries:
  • Power plants
  • Chemical plants
  • Ship yards
  • Factories
  • Oil refineries
  The cores of concrete blocks are filled with insulation that may be in the form of liquid foam or loose foam beads.
  Asbestos-containing insulation that is whole and intact may not cause health risks. Insulation that has been cut, torn or disturbed through renovation or demolition may emit asbestos fibers into the air. Installing or removing asbestos insulation may expose homeowners, construction workers and employees to asbestos.
  Approximately 1.3 million construction workers are at risk of becoming exposed to asbestos on the job, according to the Environmental Protection Agency.

Pipe Covering and Air Cell Pipe Covering

  Pipe insulation may be applied to heating pipes, water pipes and drains and helps pipes maintain a consistent temperature. Air cell pipe coverings are a type of insulation used to cover pipes and may resemble corrugated paper or cardboard.
  Pipe coverings are typically wrapped around pipes or ductwork and may be located in the following areas:
  • Ceilings
  • Garages
  • Basements
  • Furnace systems
  • Heating and air systems
  Over time, pipe coverings may become brittle and may break off from the pipe.  Once airborne, asbestos fibers may be inhaled or ingested by contractors, insulators, plumbers or anyone exposed to the fibers in their home or office.
  Pipe coverings were often fitted to pipes on-site and may have been cut or sawed. Asbestos fibers enclosed in insulation material can become airborne for hours or days.
  Undamaged asbestos pipe coverings may be covered with newer insulation as a preventative safety measure. Crumbling or frayed pipe coverings should be removed by professionals who are trained and certified to remove damaged asbestos.
Asbestos Sheets, Gold Bond Asbestos Sheets, Asbestos Cement, Gold Bond Cement
  Asbestos-containing sheets are a type of construction material that may have been used in the following areas:
  • Roofing
  • Ceilings
  • Walls
  • Floors
  • Furnaces
  • Duct work
  • Boilers
  Asbestos sheets are typically made out of fiber cement or a material known as Portland cement and may appear rippled or grooved. Sheeting may be applied as a siding or insulation material in residential homes or commercial buildings.
  The National Gypsum Company manufactured a popular asbestos sheeting product under the brand name Gold Bond during the mid-1900s. Asbestos is a durable material often used in industrial sheeting due to its strength and flame-retardant properties, as well as its flexibility.

Uses for Asbestos Sheets

  Asbestos sheets may be applied as an insulation material around pipes, boilers, and electrical products and were often corrugated, or ridged, to mold easily to any shape. Insulation sheets were commonly used to stop or prevent the spread of fire in various structures.
  Asbestos sheets could be applied in the following locations:
  • Homes
  • Factories
  • Refineries
  • Schools
  • Hospitals
  • Offices
  Gold Bond sheets were often made of asbestos cement and were used as siding materials.

Uses for Asbestos Cement and Gold Bond Cement

  Sheet siding material and Gold Bond cement were made from asbestos cement, a material which was comprised of sand, cement and asbestos fibers. Sheet siding is placed on walls, ceilings and roofs and is used to prevent damage from water and the elements.
  Asbestos cement was often supplied as siding, shingles, flat sheets, roofing shingles and corrugated sheets. These products may resemble wood siding and could be applied as an enclosure on factory buildings, roofs, warehouses and garages.
  Cement siding that has been disturbed through installation, removal or other disturbances may emit asbestos fibers into the air.

Potential Hazards of Asbestos Sheets

  Dangerous asbestos fibers are not generally released into the air from asbestos sheet materials or cement unless the material is worn, cut or otherwise disturbed. However, the following actions are generally not recommended around asbestos-containing sheets or cement, as they may cause microscopic asbestos fibers to become airborne:
  • Sanding
  • Sawing
  • Cutting
  • Drilling
  • Chipping
  • Renovation
  • Demolition
  Asbestos sheet materials that have become friable, or easily crumbled by hand pressure, may release asbestos fibers into the air, where they can then be breathed in or swallowed by construction workers or others nearby.Asbestos-containing sheets are a type of construction material that may have been used in the following areas:
  • Roofing
  • Ceilings
  • Walls
  • Floors
  • Furnaces
  • Duct work
  • Boilers
  Asbestos sheets are typically made out of fiber cement or a material known as Portland cement and may appear rippled or grooved. Sheeting may be applied as a siding or insulation material in residential homes or commercial buildings.
  The National Gypsum Company manufactured a popular asbestos sheeting product under the brand name Gold Bond during the mid-1900s. Asbestos is a durable material often used in industrial sheeting due to its strength and flame-retardant properties, as well as its flexibility.

Uses for Asbestos Sheets

  Asbestos sheets may be applied as an insulation material around pipes, boilers, and electrical products and were often corrugated, or ridged, to mold easily to any shape. Insulation sheets were commonly used to stop or prevent the spread of fire in various structures.
  Asbestos sheets could be applied in the following locations:
  • Homes
  • Factories
  • Refineries
  • Schools
  • Hospitals
  • Offices
  Gold Bond sheets were often made of asbestos cement and were used as siding materials.

Uses for Asbestos Cement and Gold Bond Cement

  Sheet siding material and Gold Bond cement were made from asbestos cement, a material which was comprised of sand, cement and asbestos fibers. Sheet siding is placed on walls, ceilings and roofs and is used to prevent damage from water and the elements.
  Asbestos cement was often supplied as siding, shingles, flat sheets, roofing shingles and corrugated sheets. These products may resemble wood siding and could be applied as an enclosure on factory buildings, roofs, warehouses and garages.
  Cement siding that has been disturbed through installation, removal or other disturbances may emit asbestos fibers into the air.

Potential Hazards of Asbestos Sheets

  Dangerous asbestos fibers are not generally released into the air from asbestos sheet materials or cement unless the material is worn, cut or otherwise disturbed. However, the following actions are generally not recommended around asbestos-containing sheets or cement, as they may cause microscopic asbestos fibers to become airborne:
  • Sanding
  • Sawing
  • Cutting
  • Drilling
  • Chipping
  • Renovation
  • Demolition
  Asbestos sheet materials that have become friable, or easily crumbled by hand pressure, may release asbestos fibers into the air, where they can then be breathed in or swallowed by construction workers or others nearby.
Asbestos Paper & Gold Bond Asbestos Paper
  Asbestos paper and Gold Bond paper are types of insulation material made of asbestos fibers and binder, or starch. These paper products were used to cover industrial equipment and were applied as a backing material in building construction.
    Asbestos was commonly added to paper insulation materials as asbestos fibers are strong and resistant to heat and fire.

Asbestos Paper

  During the mid-1900s, asbestos paper was commonly applied as an insulation material to the following products:
  • Pipes
  • Electrical equipment
  • Boilers
  • Furnace ducts
  • Flue vents
  • Wood-burning stoves
  • Fiberboard backing
  • Floor tile backing
  • Air conditioning units
  Asbestos paper was also used to seal joints in heating ducts and may appear corrugated, or ridged.
  Paper materials are commonly applied outside of ductwork but may also be used inside ductwork as a lining for studs, floor joists or vibration damper material.
  This material may be difficult to identify by sight alone. If you suspect asbestos materials have been used in your home or office building, a sample should be taken from the paper and sent to a lab to indentify the types of fibers used in the paper.
  Those who have handled asbestos paper while installing or removing the material may have been exposed to asbestos fibers. Paper that has remained intact and whole may not pose risks to health, but paper that has been ripped, torn or frayed may release asbestos fibers into the air.
  If used in or around air ducts, asbestos fibers may be sucked into the air passages and dispersed throughout a home or building.

Gold Bond Asbestos Paper

  Gold Bond asbestos paper is a brand name product manufactured by the National Gypsum Company.  The company produced a wide variety of asbestos products during the early 1900s including wallboards, roofing shingles, cements and siding.
  These products were applied to the exterior and interior of structures such as schools, libraries and theaters.
  Other manufacturers who produced asbestos paper include:
  • Armstrong World Industries, Inc.
  • GAF/Ruberoid
  • Grant-Wilson, Inc.
  • Reynolds Metals Company
  • Westinghouse Electric Company
  Gold Bond asbestos paper that has been disturbed may also emit asbestos fibers, which may remain airborne for hours or days.

Asbestos Paper and Mesothelioma

  Airborne asbestos fibers can be breathed in or swallowed by homeowners or construction workers who may be near the asbestos-containing paper products. The fibers can remain lodged in the lining of the lungs once in the body. The fibers cannot be removed and may cause irritation and inflammation.
  Over time, the presence of the fibers can lead to severe health conditions such as asbestosis, lung cancer or mesothelioma.
Asbestos Permaboard, Rollboard and Flex Board
  Permaboard, roll board and flex board are types of construction materials used to provide insulation from heat, fire, sound and water in various structures. Similar to plasterboard or cement board, the products often contained asbestos fibers in the period between the 1950s and the mid-1970s. The asbestos content of various insulating board materials used during this time ranges from 15 to 40 percent.
    Asbestos insulating boards such as Permaboard, asbestos roll board and asbestos flex board could be found in the following locations:
  • Duct work
  • Fire door panels
  • Soffits
  • Wall partitions or linings
  • Ceiling tiles
  • Roof underlay
  • Tile backing
  • Boilers
  • Ovens

Permaboard

  Permaboard is a brand of asbestos-cement board that was trademarked in 1953 by the National Gypsum Company and was used widely until 1981 in residential homes and other buildings. Also referred to as asbestos flat sheets or asbestos-cement wallboard, Permaboard typically contained a mixture of cement and asbestos sandwiched between two protective sheets. The board was used for both exterior and interior partitions or in areas where insulation from heat, fire, water and sound was necessary, such as around boilers, furnaces or wood-burning stoves. Permaboard was sold under the brand name Gold Bond Asbestos Permaboard.

Rollboard

  Similar to millboard, rollboard is a material that was frequently used to provide fireproofing and insulation in commercial, residential and industrial structures. The material could be found in ceilings, walls, partitions, stoves, furnaces, electrical boxes, garage paneling and in other areas where fireproofing was needed.
  Rollboard is supplied as a flexible, rolled sheet, made with two sheets of asbestos paper glued together. Testing shows that the material commonly contained 70 to 80 percent asbestos. Used from the 1950s until the 1980s, asbestos rollboard was banned in 1989 by the U.S. Environmental Protection Administration and remains banned in the U.S. today.

Flex Board

  Flex board is another insulating board material that commonly contained asbestos prior to the 1980s. Consisting of cement and asbestos pressed and then re-pressed together into flat sheets, flex board offered both flexibility and protection from fire in walls, ceilings, countertops, garages, fireplaces and other locations.

Dangers of Permaboard, Rollboard & Flex Board

  Insulating board materials made with asbestos can pose a serious health hazard if the asbestos fibers are released into the air during installation, excessive use or demolition. If inhaled or ingested, microscopic asbestos fibers can lodge in the lungs and other body organs, leading to lung cancer, mesothelioma and other serious health complications in later life.
  Asbestos fibers can be released from Permaboard, rollboard or flex board upon installation or when the materials are sawed, snapped, sanded or drilled. Asbestos fibers may also be released if the boards are damaged from wear and tear, water damage, vibrations or humidity.
  Individuals who manufactured asbestos-containing Permaboard, rollboard or flex board may have been exposed to asbestos fibers in factories, and their families may also have been exposed through asbestos fibers that remained on the workers' clothing, boots or hair. Shipbuilders, construction workers, remodelers, demolition crews and other people who came into contact with asbestos Permaboard, rollboard or flex board may have inhaled or ingested asbestos fibers.
  The following manufacturers may have used asbestos in their insulating board materials and factories:
  • National Gypsum Co.
  • Armstrong Cork Co.
  • Elof Hansson Inc.
  • Wood Conversion Co.
  • Johns-Manville Sales Corp.
  • The Celotex Co.

Asbestos Sheetrock and Taping Compounds
  During the 1900s, a variety of construction materials were manufactured using asbestos. Two common building materials made with asbestos include:
  • Sheetrock
  • Taping compounds
    Although construction materials no longer incorporate asbestos into the products, many offices, schools, older homes and other buildings may still contain asbestos fibers.

Sheetrock

  Sheetrock that contains asbestos has been used in the walls and ceilings of a large number of houses, businesses and other buildings constructed before the mid-1980s. While the term Sheetrock is often used interchangeably with drywall, Sheetrock is actually a specific brand of drywall manufactured by the United States Gypsum Company.
  Sheetrock is primarily composed of gypsum plaster but was also made with asbestos for decades. Asbestos not only added insulation, fire-resistance and durability to Sheetrock, but it was also very inexpensive.

Taping Compounds

  Taping compounds that contain high amounts of chrysotile asbestos have been used frequently in the construction industry since the conclusion of World War II. Taping compounds were often mixed together with water at construction sites, and were used to eliminate gaps or seams between drywall sheets.
  Taping compounds pose a risk of dangerous asbestos exposure when the compounds are mixed or disturbed during the process of sanding walls that contain the substance. Sweeping the floors after sanding walls containing taping compounds can also increase the risk of asbestos exposure.
  In a study of 69 drywall tapers in New York who were exposed to asbestos-containing taping compounds for 10 years or longer, 37 out of 63 X-ray films taken of the individuals showed abnormalities characteristically caused by asbestos exposure.

Sheetrock, Taping Compounds and Mesothelioma

  When Sheetrock or taping compounds are damaged, fibers may become airborne and inadvertently ingested or inhaled by those in the immediate area.
  Once asbestos fibers enter the body, they cannot be broken down. Instead, they can become lodged in body tissues, such as those that line the lungs and the gastrointestinal tract. Over time, the irritation of the fibers may lead to inflammation and, in some cases, the development of a rare cancer known as mesothelioma.

Individuals Affected by Asbestos Sheetrock and Taping Compounds

  Some workers may have a higher chance of becoming exposed to asbestos due to their occupation, including handling Sheetrock and taping compounds. The following occupations can be associated with a high risk of asbestos exposure:
  • Maintenance workers
  • Demolition workers
  • Manufacturing workers
  • Construction workers
  Others who may have been affected by Sheetrock and taping compounds include homeowners, office workers and students.
Stone Corrugated Sheets & Stone Sheathing
  Stone corrugated sheets and stone sheathing are materials commonly used in the construction of industrial buildings, residential homes and other structures. Stone corrugated sheets, also called corrugated asbestos-cement sheathing or corrugated asbestos sheets, were commonly manufactured with asbestos fibers in the United States from the 1920s to the 1980s. The products were known to contain 20 to 45 percent asbestos.

Manufacturing and Uses of Asbestos Stone Corrugated Sheets & Stone Sheathing

  Asbestos-containing stone corrugated sheets were used in place of corrugated iron-on roofs or as siding for walls to provide structural support and protection from fire. Corrugated asbestos-cement sheets were commonly manufactured using cement, water and asbestos fibers of the chrysolite type.
  The mixture of cement, water and asbestos was layered and then pressed between metallic plates with heavy pressure to squeeze out excess water and create a corrugated pattern, which appears as a series of parallel ridges that add strength to the cement sheets. By mixing asbestos with cement, the sheets could protect structures from moisture, as well as provide insulation from heat and fire.
  Sheathing refers to the covering that is applied to the studs and framework of a structure, beneath the siding, clapboard or other exterior surfaces. Before asbestos sheathing was utilized in construction, fires could easily spread through the walls and joints in the siding, engulfing a structure in flames within a short period of time.
  Asbestos corrugated sheets and sheathing was used in the following types of structures:
  • Residential homes
  • Industrial buildings
  • Railroad buildings
  • Temporary structures
  • Emergency structures

Dangers of Asbestos Stone Corrugated Sheets & Stone Sheathing

  Asbestos-containing corrugated sheets used as siding and roofing materials may pose a health hazard if the microscopic asbestos fibers are released into the air during installation or renovation. If asbestos corrugated sheets or sheathing is power washed, sanded, sawed, drilled, removed or otherwise disturbed, the fibers can become airborne and pose a serious health risk if inhaled or ingested.
  People at risk for exposure to asbestos in corrugated asbestos-cement sheets or sheathing materials may include:
  • Construction workers
  • Remodelers or renovators
  • Demolition crews
  • Factory workers who manufactured the products (such as those who were employed at Asbestos Shingle, Slate, and Sheathing company or Turner's Asbestos Cement Company)
  If asbestos fibers are inhaled or ingested, the tiny fibers can become lodged in lung tissue or digestive tissue, where they can then cause damage, inflammation and possibly cancer many years later. Asbestos exposure has been linked to serious diseases such as mesothelioma, lung cancer, asbestosis and other conditions.
Asbestos Seals, Sheets & Sponge Block
  Asbestos seals, sheets and sponge block are common materials used in roofing. Seals are used to prevent leaking in roofing materials by joining roofing shingles together. Sheets may be made out of asbestos-cement and are used in construction as roofing materials. Sponge block is a type of insulation material used in residential homes and commercial buildings to protect against extreme temperatures.
    These roofing materials may contain asbestos if manufactured during the mid-1900s due to the natural heat-resistant qualities found in asbestos fibers.

Asbestos Seals

  Seals, or packing, protect the roofs of homes and other structures against high temperatures and caustic substances. Roof seals prevent leaking and weather damage and have been used to protect against the following:
  • Bleaching
  • Cracking
  • UV exposure
  • Rain damage
  Asbestos-containing seals may wear down over time and can flake or peel away.
  Worn or old seals that are no longer intact can emit asbestos fibers in the air, which poses a health risk to those in contact with the seal. Seals that remain solid or intact are not considered to pose a health risk.

Asbestos Sheets and Sponge Block

  Roof sheets or shingles that have been made from asbestos-cement and sponge block, or foam block, were used as roofing insulation material. Roof sheets and sponge blocks may be applied to the following areas:
  • Outbuildings
  • Warehouses
  • Garages
  • Ceilings
  • Walls
  Roofing sheets were often reinforced with asbestos fibers due to the material's durability, and sponge block can contain as much as 20 percent asbestos.
  Asbestos sheets that are friable, or easily damaged by hand pressure, should be removed, however, sheets that are whole and undamaged may remain in place if deemed non-friable.
  Heat, water, weathering and aging may weaken roofing sheets, and sawing, cutting, sanding or drilling sheets may make asbestos fibers airborne. Construction workers may have been exposed to asbestos fibers during the installation, removal, renovation or demolition of homes or buildings.

Asbestos Roofing Materials and Mesothelioma

  Damaged seals, sheets or sponge block may create airborne asbestos fibers that can remain in the air for days. Workers, homeowners or employees may breathe in or inhale the fibers, causing damage to the respiratory system.
  The fibers can become lodged in the mesothelium, or the thin membrane that surrounds the lungs, abdomen and heart. Asbestos can irritate and inflame the mesothelium, which can lead to lasting health conditions such as asbestosis, lung cancer and mesothelioma.
Asbestos Adhesives and Gold Bond Adhesives
  Adhesive is a type of liquid or paste that is used to bond items together. This product is commonly used in construction and may be used to bond the following products:
  • Ceiling tiles
  • Floor tiles
  • Plywood panels
  • Concrete
  • Asphalt
  • Leather
  • Fabric
    The National Gypsum Company was one of the largest manufacturers of asbestos adhesive during the early 1900s. The company's product, Gold Bond adhesive, was a popular adhesive brand and was widely used in residential homes and commercial buildings.
    Asbestos has been added to adhesive products due to the strength of the fibers and the product's natural resistance to fire and caustic substances.

Asbestos Adhesive

  Asbestos-containing adhesives include a variety of products such as:
  • Emulsion adhesive
  • Lagging adhesive
  • Rubber cements
  • Fibrous adhesive
  • Vinyl adhesive
  • Mastics
  • Duct adhesive
  • Drywall adhesive
  Adhesives are commonly used as a bonding agent during construction and may have contained between 1 and 25 percent asbestos.
  Adhesives may also be applied to heating and cooling systems, roofing ceiling or flooring tiles and wallboard. This product may be applied in a spray form or could be troweled on to surfaces
  Asbestos fibers may remain encapsulated within the adhesive, and whole or intact adhesive does not pose health risks. Adhesive that has worn down over time due to weathering, renovations or demolition may cause serious conditions.
  Asbestos that has crumbled or disintegrated into a powder or dust through the use of hand pressure is considered to be friable, or able to emit asbestos fibers into the air. Asbestos fibers may also become airborne through sanding, grinding or drilling adhesive-applied materials. The mineral may be hazardous when fibers become airborne.

Gold Bond Adhesive

  Gold bond adhesive is a brand name product used mainly in the installation of ceiling and floor tiles. This product was manufactured with asbestos fibers around the 1950s by National Gypsum Company, an industrial product manufacturer.
   People who worked in the following occupations may have been exposed to asbestos materials:
  • Drywallers
  • Insulators
  • Plasterers
  • Roofers
  • Tile or linoleum installers
  • Demolition crews
  • Building material product manufacturers
  • Laborers
  During the installation, manufacturing, removal or renovation of asbestos adhesive products, workers may be exposed to asbestos fibers.

Adhesives and Mesothelioma

  If asbestos adhesive products are disturbed, microscopic asbestos fibers may be released into the air. Once airborne, fibers may be inhaled or ingested by those nearby as asbestos may remain suspended in the air for hours or days.
  In the body, asbestos fibers can become lodged in the thin membrane that covers the lining of the organs. The fibers can cause irritation and inflammation over time and may lead to life-threatening health conditions such as lung cancer, asbestosis and mesothelioma.
Asbestos Tar Paper, Gold Bond Tar Paper
  Tar paper is a type of roofing paper that is frequently used in construction. The material consists of a heavy-duty paper that has been reinforced with tar to provide waterproofing features. This material is applied to roofs to protect against weathering and to insulate homes. Gold Bond is a line of brand name products that were manufactured by the National Gypsum Company during the early and mid-1900s, and asbestos-containing tar paper was a popular construction product.
    Tar paper and Gold Bond tar paper were often embedded with asbestos fibers, as asbestos is known to be sturdy, flexible, durable and resistant to fire and caustic substances.

Uses for Asbestos Tar Paper

  Tar paper, also called felt paper, is used to waterproof roofs by preventing moisture from seeping inside the structure. Tar paper may also be used as a backing for the following construction products:
  • Asphalt
  • Wood
  • Shingles
  • Gravel
  • Shower stalls
  • Linoleum or vinyl flooring
  • Hardwood floors
  The paper is usually applied in overlapping layers and is prone to ripping or tearing, which can allow asbestos fibers to become airborne.
  People in certain occupations such as roofing professionals, contractors and maintenance workers may have been exposed to asbestos when handling, installing or removing tar paper.
  Weather damage and the breakdown of materials over time may cause tar paper to become friable, which refers to the ability of a product to crumble or disintegrate with little effort.

Gold Bond Tar Paper

  Gold Bond tar paper has been applied to residential homes and commercial buildings and was also used in numerous schools and factories. This type of roofing material may contain between 10 and 15 percent asbestos.
  Tar paper may be installed using roofing nails or may be applied using adhesives. During the process of installing, repairing or removing tar paper, exposure to asbestos fibers may occur.
  Certified asbestos abatement professionals should be contacted to remove Gold Bond tar paper. This product should not be removed by those who are untrained in handling hazardous materials.

Tar Paper Dangers

  Torn, ripped or damaged tar paper may emit asbestos fibers into the air. Roofing professionals as well as homeowners or those who work in other asbestos-containing buildings may breathe in or swallow the fibers. Once in the body, the fibers may become lodged in the body, where they can contribute to the development of cancer and other asbestos-related diseases many years after exposure.
Base Flashing & Asbestos Felt
  Asbestos-containing base flashing and asbestos felt was commonly found on the roofs of homes built between the 1940s and 1980s.
    Base flashing, also known as weatherproofing, is used to create a water-tight seal around roof protrusions such as vents, skylights, chimneys or walls in order to protect a structure from water leaks and the elements.
    Asbestos felt, or asbestos roofing felt, was often used under base flashing to provide homes with thermal insulation and further protection from water damage.

Asbestos in Base Flashing & Felt

  Now typically made of metals such as copper, aluminum, lead or steel, base flashing was once made with asbestos fibers or asbestos felt. Asbestos fibers in roofing materials offered a low-cost means to provide thermal insulation, high tensile strength, flexibility and fire resistance to roofs in the mid-20th century. Asphalt shingle roofs, flat roofs and built-up roofs were often constructed using asbestos-containing base flashing and felt materials. The adhesives used to attach the base flashing and felt to roof shingles and roof sheathing also frequently contained asbestos fibers.
  Asbestos felt was a type of tar paper that was applied to roof surfaces in the form of a large roll. The material was commonly used to provide a waterproof barrier between sheathing and roofing shingles or other roofing surfaces, and the material could often be found on built-up roofs. Asbestos fibers in roofing felt offered additional reinforcement, as the strong fibers could resist the pulling force of the roofing material. Asbestos felt from the 1950s to the 1970s was known to contain an average of 10 to 15 percent chrysotile asbestos fibers.

Dangers of Base Flashing & Asbestos Felt

  The U.S. Environmental Protection Agency (EPA) has since eliminated the use of asphalt-saturated asbestos felts used as base flashing. Considered a "nonfriable," Category I ACM (asbestos-containing material) by the EPA, asbestos base flashing and felt may pose a health hazard only if the material is significantly aged, damaged or weathered. If severely worn, the material can be considered "friable," which means that asbestos fibers may break free and become airborne. If airborne asbestos fibers are inhaled or ingested, the fibers can lodge within the body and increase the risk of serious health conditions such as lung inflammation, lung cancer, asbestosis or mesothelioma.
  Asbestos-containing base flashing or felt should never be ripped, sanded, drilled, cut, scraped or otherwise disturbed in order to avoid releasing asbestos fibers into the air.
Individuals at risk for exposure to asbestos roofing materials such as base flashing or asbestos felt include:
  • Roofers or slaters
  • Construction workers
  • Remodelers
  • Demolition crews
  • Homeowners

Construction Mastics & Gunning Mix
  Mastics and gunning mix are building materials used to repair or fill industrial materials such as furnaces, tile or flooring. Asbestos was commonly added to these products as it is strong, durable and able to withstand high temperatures.

Construction Mastic and Gunning Mix

  Mastic is a paste-like cement that is used as an adhesive, sealant and joint-filler. This product may be used in residential homes or commercial buildings in areas such as:
  • Under floor tiles
  • Ceiling tiles
  • Acoustical tiles
  • Roofing
  • Walls
  • Windows
  The National Emission Standards for Hazardous Air Pollutants considers construction mastic to be a Category I non-friable asbestos-containing material. This classification indicates that mastic contains 1 percent or more asbestos and may emit asbestos fibers if disturbed.
  Mastic may become friable, or able to become reduced to powder with little pressure, through the following actions:
  • Grinding
  • Sawing
  • Drilling
  • Cutting
  • Abrading
  • Renovating
  • Demolition
  Gunning mix is also a type of paste that is may be applied to metals, plastics, wood or masonry as a repair compound. This product is commonly used to fill in gaps or spaces in the surfaces of the following equipment:
  • Steel furnace lining
  • Hulls
  • Storage tanks
  • Sonar domes
  • Pump casings
  Gunning mix may also be used to smooth pitting, rough surfaces or irregularities that may occur in equipment lining.  Over time, asbestos-containing gunning mix may disintegrate or crumble. This may expose those who contact gunning mix or may be nearby the material to asbestos fibers.
  Construction workers who install, remove, repair or perform other maintenance to structures may have been exposed to asbestos. Fibers that have been emitted from asbestos materials can remain airborne for several hours or days and can be breathed in or swallowed by those in contact with the material.

Removing Asbestos Mastic

  Asbestos-containing construction mastic may be applied to a variety of household products such as floor tiles or roofing materials. Homeowners may remove mastic that is whole and intact. Mastic that has been applied to insulation board or lagging should be removed by a certified asbestos abatement contractor.
  Homeowners should follow the following guidelines when removing asbestos-containing mastic:
  • Remove all furniture or personal items from the room
  • Cover nearby objects with sheeting to avoid contamination
  • Wear proper safety equipment
  • Scrape off mastic that has been softened though heating or applying a solvent material
  • Avoid creating dust or scattering pieces of mastic
  • Wipe down surfaces and clean the area with a vacuum
  • Seal debris in polythene bag and dispose of the materials in an asbestos-approved garbage location
  Many states require homeowners to use professional, trained contractors when removing asbestos products.

Construction Mastic, Gunning Mix and Mesothelioma

  Asbestos fibers that have been inhaled or ingested may remain lodged in the body, as fibers can become caught in the thin membrane that surrounds internal organs such as the lungs, heart and abdomen.
  Once in the body, the fibers cannot be expelled and can cause irritation and inflammation. The continued irritation of the membrane lining can cause life-threatening health conditions, which include lung cancer, asbestosis and mesothelioma.  
Asbestos Wallboard Plaster & Gold Bond Perfo-Lyte
  Perfo-lyte is brand name wallboard plaster that was manufactured by the National Gypsum Company and was a part of the Gold Bond line of products. Wallboard plaster was used during construction as an insulation material and contained asbestos fibers due to the material's durability and flame-retardant properties.

Asbestos Wallboard Plaster

  Plaster is a paste that is used as a fireproofing material and is applied to building materials such as wallboard. Wallboard plaster is applied to the interior of homes or commercial buildings to soundproof rooms and provide protection in the event of a fire. 
  Plaster works to slow the spread of fire as it releases water vapor when exposed to flames. The material also reinforces steel supports to prevent a structural collapse. Wallboard plaster was made of mineral wool, cement mixtures combined with mineral wool or gypsum plasters.
  Asbestos wallboard plaster was commonly placed in ceilings and walls and is difficult to identify by sight alone. To determine the presence of asbestos-containing plaster, the following may be performed:
  • Determine the date the building, home or office was constructed
  • Look for plaster that is disintegrating or damaged
  • Take a sample of the plaster to be tested by lab professionals
  • Contact an asbestos abatement professional to remove plaster materials
  Asbestos wallboard plaster that has been disturbed may allow asbestos fibers to become airborne. Drilling, sanding or cutting asbestos wallboard can release asbestos fibers into the air, allowing constructor workers or anyone nearby to inhale or ingest the fibers.
  Asbestos exposure may also occur during the installation or removal of wallboard plaster and renovation or demolition work may also disturb the asbestos materials.

Gold Bond Perfo-Lyte

  Gold Bond Perfo-lyte was a popular insulation material during the mid-1900s. This product is no longer manufactured but may still be present in homes constructed before the 1970s.
  The National Gypsum Company also manufactured other Gold Bond asbestos products such as:
  • Drywall
  • Siding
  • Joint compound
  • Cement
  • Adhesives
  • Permaboard
  • Texture paint
  Intact Perfo-lyte board is not considered to pose a health risk. Asbestos wallboard that has broken or crumbled may allow asbestos fibers to become airborne and should be removed.
  Commercial buildings such as schools and businesses must meet national safety standards during the removal of asbestos wallboard. Homeowners are not advised to remove asbestos materials by themselves and should contact a professional asbestos abatement team to remove the hazardous materials.
HVAC Ductwork Insulation, Heat Guards & Heating Ducts
  Ducts are used in Heating, Ventilating and Air Conditioning (HVAC) systems to supply or remove air and maintain air quality and air temperature. HVAC ductwork is often lined with a fiber board material that resists the flow of heat in the ducts.
    Heating ducts are part of an HVAC system and may be comprised of insulation and heat guards, or a duct cover that provides additional insulation. Until the 1980s, these HVAC products were commonly manufactured using asbestos fibers, as this material is naturally resistance to high temperatures.

HVAC Ductwork Insulation

  HVAC ductwork present in residential homes and commercial buildings is used to reduce humidity levels and control carbon monoxide levels. Ductwork insulation is commonly made of rigid fiber board that consists of fiberglass or mineral wool.
  Asbestos fibers were commonly added to these materials to add strength and fire resistance. Ductwork is commonly placed in the following home locations:
  • Attics
  • Crawl spaces
  • Garages
  • Unfinished basements
  Insulation is typically applied to ducts after ductwork has been installed and can be used on the duct exterior. The fiber board may also be covered with insulating cement, canvas or weatherproof mastic or joint sealant.
  HVAC ductwork insulation may fray or tear over time and release asbestos fibers into the air. Contract workers who install, remove or repair ductwork insulation may be exposed to asbestos. People living in homes or working in buildings with asbestos HVAC insulation may also breathe in or ingest the fibers.

Heat Guards and Heat Ducting

  Heating ducts may be present in different types of heating systems such as:
  • Central heating
  • Boilers
  • Furnaces
  • Heat pumps
  • Forced air systems
  • Radiators
  • Vents
  Asbestos fibers were woven inside insulation material, which keeps the air that flows throughout the heating system warm. Pipes and ductwork manufactured during the early 1900s may be made out of transite, a type of cement that contains asbestos.
  Heating ducts may be present in furnace rooms located in residential homes or in mechanical rooms in commercial buildings. Heat guards are placed on heating ducts to cover the area and act as an additional method of insulation. This helps maintain the internal temperature within the machinery.
  Asbestos fibers inside the ductwork cement may be disturbed if sawed, cut, broken or sanded. The insulation material may also wear down over time and become friable.  Ductwork and insulation that is whole and intact is not considered to be a health hazard, but products that are damaged or disturbed may pose health risks.
Boiler Wall Coat & Expansion Joint
  Boiler wall coat and expansion joints are materials applied to industrial equipment to insulate the products. Boiler wall coat is a type of paint that is placed on the exterior of boilers to prevent heat from escaping the machine.
    Expansion joints are available as a variety of products including a type of caulk or metal piece and are used to hold separate parts of buildings or other structures together. Asbestos fibers were often added to these products as the material is resistant to caustic substances and extreme temperatures.

Boiler Wall Coat

  Boiler wall coat is a base coating that may be applied to the interior or exterior of industrial equipment and can withstand temperatures as high as 1200 degrees Fahrenheit.
  Asbestos-containing boiler wall coat may be applied to the following:
  • Engine parts
  • Furnaces
  • Boilers
  • Exhaust stacks
  • Grills
  • Hoods
  • Stoves
  This insulation material was commonly applied to oil, coal, gas or wood furnaces in homes, buildings, engine rooms, shipyards and power plants. Although boiler wall coat that is currently manufactured does not contain asbestos, buildings that were constructed between the 1930s and 1970s may have asbestos insulation materials.
  Boiler wall coat that is intact and whole is not considered to pose a health risk. The material is considered to be dangerous if it has begun to disintegrate or has become friable, or able to crumble into a dust with light pressure. Asbestos may become friable through sanding, grinding or sawing the material.

Expansion Joint

  Expansion joints are metal pieces that help hold parts of construction together and aid in reducing the damaging effects of vibration. This product connects parts of the following construction materials:
  • Sidewalks
  • Bridges
  • Railway tracks
  • Piping systems
  • Ships
  • Ductwork
  Extreme temperatures may cause buildings or other structures to expand or contract, resulting in structural stresses and cracks. Expansion joints work to relieve stress by allowing the movement of parts, especially in the event of an earthquake.
  Expansion joints may also be available as a caulk, which is used to create a division between solid materials such as veneer walls, concrete or concrete block. Rubber and fabric may be used to reinforce the expansion joint.
  Asbestos fibers encapsulated within the expansion joint may be released from the material during the process of installing, repairing or removing the asbestos material. Renovation or demolition of a structure may also disturb the expansion joint, emitting fibers into the air.

Boiler Wall Coat, Expansion Joints and Mesothelioma

  Asbestos fibers that have become airborne may be breathed in or inhaled by those nearby the material. Inside the body, the microscopic fibers may become caught in the thin membrane that surrounds the lungs, heart and abdomen.
  The prolonged presence of the fibers in the membrane can cause swelling and inflammation. Over time, this may cause life-threatening health conditions such as mesothelioma or asbestosis.
Floor Backing & Drywall Taping Compounds
Floor backing and drywall taping compounds are materials used in building construction. Floor backing is a type of insulation material that is used to cushion flooring, and drywall taping compound is a paste-like mixture that is used to close gaps between drywall sheets.
Products manufactured prior to the late 1900s often contained asbestos fibers, as the material is resistant to weathering, extreme temperatures and caustic substances.

Floor Backing

Floor backing is used to prevent moisture absorption and may be applied to the following materials:
  • Vinyl flooring
  • Tiles
  • Sheet flooring
  • Linoleum
  • Asphalt floor tiles
  • Floor adhesives
This material has been applied commonly in homes as well as commercial buildings, schools, hospitals and stores.
Floor backing that is intact may not release asbestos fibers as long as the tile is whole and undamaged, but worn or broken tiles may emit asbestos fibers into the air. Floor backing that has become friable, or able to crumble with the use of hand pressure, is considered to be a health hazard.
During the construction of a home or building, construction workers or homeowners may be exposed to asbestos. The following actions may disturb asbestos floor backing:
  • Cutting
  • Sanding
  • Breaking
  • Sawing
  • Scraping
The removal of floor tiles or the renovation or demolition of a home may also allow asbestos fibers to become airborne.

Drywall Taping Compound

Drywall taping compound is a type of paste or putty that is used as a finish for installed drywall. The product covers gaps between drywall sheets and smoothes over and covers the areas where nail and screws have been inserted.
Thin paper, or tape, is also applied on top of the drywall to create seamless drywall sections and may be sanded and reapplied several times. The process of applying drywall taping compound may expose workers or people nearby to asbestos.
Asbestos fibers that have become airborne can be ingested or inhaled. Professional drywallers and homeowners are typically exposed to asbestos drywall taping compound during the construction of a home or commercial building.
The following procedures may cause asbestos to be released into the air:
  • Sanding the compound
  • Cutting or applying the compound to drywall
  • Mixing the compound with other powdered drywall materials
  • Sweeping or vacuuming floors after sanding has occurred
Asbestos fibers that have been disturbed and emitted from the drywall taping compound can remain airborne for hours or even days.
Asbestos Tape
  Asbestos tape was commonly used in residential and commercial buildings prior to the 1980s to provide insulation for hot water pipes, furnace ducts, air conditioning ducts and other elements of heating and cooling systems.
  Asbestos tape appears very similar to what we now call duct tape, but asbestos tape was manufactured with asbestos fibers or asbestos fabric in a light-grey or white color.

Uses for Asbestos Tape

  Asbestos tape was primarily used to hold metal air ducts together at joints and prevent air leaks while also providing flame-resistance. Sometimes asbestos tape was used to join together drywall panels.
  The tape was used as insulation and protection for the following elements of HVAC (heating, ventilating and air conditioning) systems:
  • Heating and cooling units
  • Steam pipes
  • Furnace ducts
  • Hot water pipes
  • Air ducts
  • Air conditioning pipes
  • Electrical wire
  • Joining drywall sheets

Potential Hazards of Asbestos Tape

  Asbestos tape installed prior to 1986 has been found to contain as much as 80-percent asbestos fibers. The asbestos contained in asbestos tape poses a significant health hazard for construction workers and HVAC mechanics who handle the installation or removal of ducting systems built prior to the 1980s.
  If the asbestos tape is torn, frayed, damaged, crumbling or exposed to extreme vibrations or air flow, the microscopic asbestos fibers within the tape can be released into the air, where they then can be inhaled by workers. Inhaled asbestos fibers from asbestos tape can lodge in the lungs, causing damage and possibly leading to the development of cancer.
  The U.S. Environmental Protection Agency warns consumers and HVAC workers that asbestos tape on ducting is dangerous to remove or disturb. If the tape is sanded or cut without being wetted or shielded, microscopic, sharp particles can be released into the air which can then be inhaled.

  
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