01. Asbestos Use in Cement Sheets
Why Was Asbestos Used in Cement Sheets?
For decades, asbestos was added to cement sheets for strength, flexibility and heat resistance. In the United States, asbestos cement sheets were commonly used in building construction. The products were often used in roofing and siding.
Asbestos cement sheeting was popular because it was easier to handle than heavy cement and more moldable for different uses. Asbestos also made cement sheets more durable and resistant to heat and weather conditions.
However, asbestos products pose a significant health threat. As materials age, get replaced or renovated, asbestos cement sheets may release airborne asbestos fibers. Inhaling or ingesting asbestos fibers can lead to serious diseases, like mesothelioma cancer.
Asbestos Cement Sheets History at a Glance
- Other Names: AC sheet, asbestos board, asbestos cement board, asbestos cladding, asbestos panel, asbestos roofing, asbestos sheets, fibrous cement sheet, roof sheets
- Years of Manufacture: Early 1900s – Present
- Military Use: Barracks, buildings, equipment
- Places Used: Commercial and residential construction, oven linings, roofing, siding, vault linings, tabletops
- Asbestos Use Banned: No
- Noteworthy Brands: GAF Corporation, Johns-Manville, Keasbey & Mattison Company, National Gypsum Company
A Brief Timeline of Asbestos Use in Cement Sheets
Some of the earliest product records of asbestos cement sheets in the U.S. come from Keasbey & Mattison Company. In 1907, the company began to manufacture and sell asbestos cement sheets from its factory in Ambler, Pennsylvania. The company branded these products as Ambler Asbestos Sheets.
Process innovations in 1910 led to more widespread manufacturing and use of asbestos cement sheets in the U.S.
By the 1950s, other large companies like National Gypsum began to introduce asbestos cement sheets to their product lineups. National Gypsum added various corrugated cement sheets and asbestos panel products to its popular Gold Bond brand.
U.S. agencies began to introduce asbestos regulations in the 1970s. By 1985, most U.S. companies had ceased using asbestos in cement sheets. However, the products are still made around the world. In some cases, asbestos sheets may still be imported into the U.S.
As of 2017, more than 90% of global asbestos use was in asbestos cement sheets and pipes. Because they were so widely used, cement sheets may still be present in some homes and buildings. Old asbestos cement sheets may put residents and workers at risk of asbestos exposure.
Dangers of Asbestos in Cement Sheets
As a result of exposure to asbestos sheets, many individuals have developed asbestos-related diseases. Residents and workers are the most at risk of exposure to asbestos sheets. These diseases include asbestosis, lung cancer and mesothelioma, among others.
In several studies, researchers documented a connection between asbestos cement workers and health risks.
For example, researchers studied 6,931 employees at an asbestos cement plant in New Orleans. The study found long-term exposure was linked to higher rates of lung cancer and mesothelioma among employees at the plant.
Asbestos cement sheets are no longer produced in the U.S. However, asbestos is still used in cement sheets in some countries. A 2021 Korean study analyzed the Excess Lifetime Cancer Risk (ELCR) of residents of corrugated asbestos cement roofed houses. The study authors rated the risk of asbestos exposure from living in or demolishing these homes as medium. However, the authors also highlighted that there is “no threshold for carcinogenicity related to asbestos” and that more studies on this exposure were needed.
Cement sheets imported from other countries may still contain asbestos, which continues to put individuals at risk.
02. List of Asbestos Cement Sheets
List of Asbestos Cement Sheets
A variety of asbestos cement products were used in the construction industry. These products were commonly made by mixing chrysotile asbestos fibers with cement. Workers would then mold the mixture into sheet form.
Asbestos sheets were used in roofs, walls, tabletops and siding. Various types of cement sheets were made with asbestos.
Asbestos flat sheets were made with cement, asbestos fiber and silica. It was particularly useful because it is water-resistant and could be molded into many shapes using a wet-molding technique.
Flat sheets had many applications, including decorative siding, fire-resistant walling, lining for ovens and vaults, laboratory tabletops and roofing. It was used in residential and industrial applications.
Corrugated asbestos sheets were manufactured with cement and asbestos fibers. These sheets contained anywhere from 15% to 40% asbestos. These asbestos sheets were a durable and affordable alternative to corrugated metal sheets.
The asbestos sheets were commonly used as siding and roofing in factories, warehouses and agricultural buildings.
Asbestos board is a type of asbestos cement flat sheet. Asbestos board was also known as cement wallboard or asbestos millboard.
It was commonly used as fireproofing and for barriers around hot equipment, such as boilers and ovens.
Asbestos lumber was also manufactured using the same flat sheet process. It was marketed as a fire-resistant alternative to actual lumber, though it contained no wood.
It was used in similar applications to plywood, such as roofing and flooring underlayment.
Companies That Produced Asbestos Cement Sheets
03. Cement Sheets & Asbestos Exposure
Who Is at Risk of Asbestos Exposure From Cement Sheets?
Carpenters, masons and other individuals who worked with asbestos sheets may have experienced occupational exposure. Individuals who made cement sheets were at a particularly high risk of exposure.
During the manufacturing process, workers often handled raw asbestos. In many cases, employees were not given protective clothing or equipment. This led to high rates of asbestos disease among cement workers and manufacturers.
Homeowners and residents may also risk exposure from asbestos building materials such as cement sheets. If asbestos sheets remain intact, they are not dangerous. However, cement products may become dangerous if workers cut into them.
During a renovation, demolition or natural disaster, asbestos sheets may crumble. Airborne asbestos may put nearby residents at risk of developing mesothelioma or another asbestos illness.
04. Asbestos Lawsuits
Asbestos Lawsuits, Settlements & Other Compensation
Asbestos victims may seek compensation by filing an asbestos claim or lawsuit. As part of bankruptcy proceedings, some companies have also established asbestos trust funds. Trust funds ensure current and future asbestos victims receive compensation.
For example, Celotex Corporation and National Gypsum Company once manufactured asbestos sheets. Both companies have established trust funds.
Compensation Following Exposure From Cement Sheets
In 2001, a San Francisco jury awarded a former employee of Johns-Manville and his wife $2.3 million. For 14 years, he worked for the company in various roles. He was later diagnosed with an asbestos-related disease. The jury determined the cause was asbestos used by Johns-Manville. The company added the mineral to many of its products, like cement sheets.
In these cases, a jury award or settlement may help victims and their loved ones cover treatment costs. Financial compensation may also help families pay for travel, end-of-life costs and other expenses.
05. Asbestos Cement Sheet Removal
Safely Removing Asbestos Cement Sheets
The Environmental Protection Agency (EPA) classifies asbestos corrugated sheets as Category II, nonfriable material. This classification means the sheets pose a health threat and must be removed before demolition or renovation work can begin.
Friability refers to a product’s ability to crumble when put under differing amounts of pressure. Though corrugated sheets are classified as nonfriable, they may degrade over time, becoming friable with wear and age.
Intact asbestos cement sheets are subject to few formal regulations for removal. The EPA recommends removing intact sheets by carefully detaching the materials from their placement and lowering them to the ground before demolishing them.
However, when the sheets are damaged, they are subject to National Emission Standards for Hazardous Air Pollutants (NESHAP) regulations. NESHAP requires at least one representative trained in the regulations to be onsite during removal and demolition. The abatement crew then must follow specific NESHAP regulations, including:
- Wetting the materials to keep the fibers from becoming airborne
- Removing the materials in whole pieces
- Sealing the wet materials in a leak-tight container
- Labeling and disposing the materials at an asbestos-qualified landfill
If asbestos-containing materials are improperly removed, the mineral’s fibers may become airborne. Asbestos in the air creates a health risk to nearby workers and residents. If asbestos fibers are inhaled, they may embed in the lungs, chest or abdomen. Over time, this may lead to mesothelioma and other illnesses.
To avoid asbestos exposure, untrained workers and residents should not attempt to remove asbestos. Individuals should hire an abatement contractor to remove or encapsulate asbestos sheets. Asbestos abatement professionals are trained to safely remove dangerous materials.