Asbestos is a category of fibrous mineral which includes six extremely durable and fire-, chemical-, electricity- and corrosion-resistant minerals. The most common form is chrysotile. The other minerals include amosite, crocidolite, tremolite, anthophyllite and actinolite. According to the Environmental Protection Agency (EPA), these minerals occur naturally in rock and soil.
The strength of asbestos, along with its durability and heat resistance, made it the material of choice in roofing shingles, floor tiles, ceiling materials, textile products, car brakes and clutches. It’s an effective insulator and is also used to strengthen products such as cloth, paper, cement and plastic. It also contaminates other building materials. For example, vermiculite, another common mineral used in insulation, may contain asbestos. More than 70% of vermiculite sold in the United States between 1919 and 1990 came from a single mine containing an asbestos deposit.
Asbestos exposure is directly linked to many lung and respiratory health conditions. All types of asbestos are known carcinogens. Inhaling or ingesting the fibers may leave them trapped in the body for decades. The first symptoms of exposure usually occur 20 to 50 years later.
Despite its health concerns, the use of asbestos is not outright banned. It’s banned in certain products, which may release asbestos fibers during use. Many manufacturers have also stopped using asbestos in their products without an official law. The EPA banned all new uses of asbestos in 1989, while existing uses are still allowed. It’s more likely to be found in buildings constructed in the 1970s or earlier. Today, the substance is highly regulated by both the EPA and the Occupational Safety and Health Administration (OSHA).
What Is Asbestos Made of?
Asbestos is a naturally occurring mineral that grows in soil and on rocks, sometimes alongside other minerals like talc and vermiculite. It grows in long, thin fibrous crystals, which stick together to form larger masses. Asbestos deposits are extracted in open-pit mines. Most deposits contain 5%-6% asbestos, with some containing up to 50% concentrations. When it’s first extracted, it looks like old wood. When it is refined, it looks fluffy and fibrous. The U.S. mined asbestos in the late 1800s through the 20th century — including in some mines in Pennsylvania and Maryland — but now imports it.
Serpentine Asbestos vs. Amphibole Asbestos
The six types of asbestos minerals break into two categories — serpentine and amphibole — based on their physical characteristics. Identifying it requires a microscope and an analysis of the crystal structures. Both types are hazardous, and any exposure may have adverse health consequences.
Serpentine asbestos has curly fibers, which develop in a layered or tiered configuration. Chrysotile, the most common form of asbestos, is the only serpentine asbestos. This type is highly regulated but still allowed in many uses. While it is sometimes considered the less toxic form, it should be treated with the same level of caution as amphibole, especially since it’s so common. Also, natural chrysotile deposits may contain trace amounts of amphibole asbestos, which increases its toxicity.
Some serpentine chrysotile products include:
- Brake pads
- Vinyl tiles
Amphibole asbestos has needle-shaped jagged fibers and a chain-like structure. Since amphiboles remain in the lung for longer periods, they are even more toxic than the serpentine variety. Exposure to amphibole asbestos is associated with a higher risk of mesothelioma than the same amount of exposure to chrysotile.
All other types of asbestos minerals fall into the amphibole category, including:
- Amosite: Right after chrysotile, amosite is the most-often used form of asbestos. It’s commonly found in insulation products, cement sheets, gaskets, roofing materials, vinyl tiles and fire protection products.
- Crocidolite: Crocidolite is the most dangerous form of asbestos. Because the fibers are so thin, they are more easily lodged in lung tissue. The material has been used in fireproofing materials, insulation, ceiling tiles and cement sheets.
- Tremolite: Tremolite doesn’t have any commercial uses. It can be found in trace amounts of other materials, including chrysotile, vermiculite and talc.
- Anthophyllite: While it has occasionally been used in construction products, anthophyllite is rare. It has been used in cement, insulation, roofing and rubber products. Like tremolite, it’s also a common contaminant in vermiculite and talc.
- Actinolite: While not usually used for commercial products, actinolite is another common incidental contaminant in other products. It has been found in paints, sealants and more.
What Color Is Asbestos?
Asbestos comes in many colors but is typically white. Chrysotile also goes by the name “white asbestos.” The two other main color varieties are brown asbestos, or amosite, and blue asbestos, or crocidolite. Here’s how you can recognize the coloration and appearance of each type of asbestos:
- Chrysotile: Known as “white asbestos,” chrysotile has white, curly fibers that give it a cotton-like or gauze-like appearance.
- Amosite: Dubbed “brown asbestos,” amosite has straight brown fibers. The coloration comes from its iron content.
- Crocidolite: Also called “blue asbestos,” crocidolite appears blue thanks to its high sodium content combined with traces of magnesium and iron. It also appears yellow or dark gray, depending on its origin and processing.
- Tremolite: Tremolite appears brown, gray, white or green and may even be translucent.
- Anthophyllite: Anthophyllite ranges from gray to white to brown.
- Actinolite: Actinolite’s iron content produces a distinctive dark green. The mineral grows in formations ranging from fibrous masses to quartz-like crystals. These qualities make it valuable as a gemstone when it forms solid, nonfibrous crystals.
About Lead and Asbestos-Containing Materials
If you work in a building built before 1980, it could have materials that contain lead or asbestos. Asbestos can appear in the following components:
- Fireproof materials and insulation
- Pipe and boiler insulation
- Wall and ceiling insulation
- Joint compound
- Wall and ceiling textures
- Floor tile and mastic
- Joint seals in ventilation duct work
- Fire rated metal doors
- Roofing materials
- Window caulking
Asbestos-containing materials can cause a serious health and safety risk if they release asbestos into the air. Keep in mind that materials such as tiles and fire doors will only release asbestos when damaged.
Lead can appear in a range of building materials, including paint. Materials that contain lead pose a danger, particularly when sanding or scraping sends lead dust into the air.
What Amount of Asbestos Exposure Is Dangerous?
The short answer is that any amount of asbestos exposure is dangerous. In high concentrations or over prolonged periods, it becomes even more hazardous. OSHA sets a permissible exposure limit (PEL) for asbestos in the workplace, at 0.1 fiber per cubic centimeter over an 8-hour time-weighted average (TWA). While maintaining this concentration lowers the risk, the agency still considers exposures below this level dangerous.
It’s critical to note that the airborne fibers are what pose a threat. Materials containing asbestos aren’t considered harmful until they release fibers into the air when manipulated or disturbed. Employees who may contact asbestos materials but will not intentionally disturb the materials should receive Asbestos Awareness Training. The training should include recognizing asbestos-containing materials, hazards of exposures, and procedures to follow after encountering damaged materials.
What Is the Flame Spread Rating of Asbestos?
One of the reasons asbestos is a popular building material is its excellent flame spread rating. Cement asbestos has a flame spread rating of zero, alongside a smoke developed rating of zero. The ASTM E84 flame spread rating test actually uses cement asbestos as its control material. It receives an automatic zero to compare it with other materials. Asbestos is used in fireproofing materials and has a Class A fire rating.
Asbestos and Lead Health Risks
A proactive operations and maintenance plan enables your company to manage the health risks of asbestos and lead. Exposure to these compounds can result in these issues:
- Asbestos: Cancer, mesothelioma, lung disorders, pleural disease and lung scarring and inflammation
- Lead: Brain damage, kidney damage, weakness, anemia, digestive issues, cardiovascular disease and reduced fertility
Diseases Related to Asbestos
When asbestos is disturbed and becomes airborne, people nearby inhale the fibers, which become trapped in the lungs. Over time, the fibers accumulate and cause scarring and inflammation, which affects breathing. It can also cause health issues after ingestion, such as drinking water from an asbestos cement pipe.
The mineral leads to serious health problems like:
- Mesothelioma: Asbestos and mesothelioma are scientifically linked. A rare form of cancer affecting the linings of the chest and abdomen, mesothelioma lung cancer is almost exclusively associated with workplace asbestos exposure. All forms of asbestos pose this risk. Family members of exposed employees and people who live near asbestos mines and factories are also at greater risk for mesothelioma. While any amount of exposure poses a threat, it increases with higher exposures. Mesothelioma takes a long time to develop and typically gets diagnosed 30 years or more after the first exposure.
- Lung cancer: Asbestos exposure has a cancer risk for many types of cancers. Lung cancer is a common and usually fatal disease associated with asbestos. All forms of asbestos may cause lung cancer, which typically surfaces at least 15 years after the first exposure. The more exposure that occurs, the higher the risk. Lung cancer risks increase dramatically with the combination of smoking and asbestos exposure. The threat is even greater than the two individual risks added together.
- Asbestosis: The risk of asbestosis, a lung disease, is also associated with asbestos. A type of pulmonary fibrosis, the condition involves scarred lung tissue. It may take up to 20 years to develop.
- Asbestos can also cause ovarian or testicular cancer, laryngeal cancer and problems with the lining around the lungs.
Asbestos in the Workplace
Asbestos exposures in the workplace are the most significant risk factor for asbestos-related diseases. While it was once more widespread than today, it’s still usually encountered in occupational settings.
Most At-Risk Workplaces
Asbestos exposures can happen almost anywhere. Even offices and commercial buildings may pose a threat if the construction includes any asbestos-containing building materials.
Some of the most at-risk workplaces include:
- Construction sites: Throughout the 20th century, 70%-80% of all asbestos products were used in the construction industry. Since the material is commonly found in insulation and building materials, construction workers are at high risk for exposure. The danger increases in workplaces that renovate older buildings.
- Shipyards: Asbestos is a common material found in older ships, especially for pipe coverings, insulation, gaskets and valves. When shipyard workers deconstruct or perform repairs on older vessels, they may disturb the material. The risk increases because the work involves being in tight quarters.
- Manufacturing facilities: Manufacturers of textiles, friction products, insulation and other materials that contain asbestos put their employees at risk.
- Automotive repair shops: Mechanics involved in brake and clutch repair work can release asbestos during their work.
OSHA has asbestos regulations for general industry, which you can find in the 29 CFR 1910.1001 standard. The administration also has specific rules for maritime workplaces, contained in the 29 CFR 1915.1001 standard. In the construction industry, you can refer to the 29 CFR 1926.1101 standard. The regulations include a maximum level of legally allowable exposure. Many states have an OSHA-approved state plan covering private and public workers.
The general industry standard requires employers to:
- Assess the workplace or construction site before work begins to determine how much asbestos exposure is possible.
- Monitor the workplace to determine if exposure increases above the maximum allowable level.
- Place signage where asbestos work is performed.
- Set up decontamination areas with proper hygiene practices and keep them separate from employee lunch areas.
- Conduct training before exposure and yearly refresher courses for workers exposed to asbestos.
- Provide medical surveillance as needed within the industry, which generally includes making medical examinations available to exposed workers.
- Maintain records for asbestos exposure for at least 30 years.
- Maintain medical surveillance records for each exposed employee through the duration of employment and for 30 years after.
Rights of Workers
Workers have several rights concerning asbestos exposure. According to OSHA, workers who may be exposed to asbestos have the right to:
- Receive training related to workplace asbestos hazards and relevant OSHA standards in a language they understand.
- Receive and wear safety gear and personal protective equipment (PPE) to limit the hazards of asbestos.
- Review workplace records of illnesses and injuries.
- See asbestos test and assessment results.
- File a complaint with OSHA and request an inspection to assess asbestos exposure or other safety hazards.
- Remain confidential when filing an OSHA complaint and exercise their rights without fear of retaliation.
In general, asbestos-related diseases are handled through workers’ compensation claims. This route is an exclusive remedy, meaning the employee or former employee may not sue the employer if they receive compensation. The employee may sue the original manufacturer of the asbestos product for additional compensation. If the company does not cover asbestos exposures in its workers’ compensation package, the employee can sue the employer.
One complication is the liability for secondary asbestos exposure. An employer’s legal responsibility for others who develop illnesses after exposure to the worker is complicated. The legal ramifications depend on the state, and asbestos laws are still evolving.