Introduction
Asbestos was once a staple in the construction industry, valued for its durability, fire resistance, and insulating properties. However, over time, the serious health risks associated with asbestos exposure have become widely recognized.
Asbestos Containing Material
Asbestos Containing Material (ACM) includes numerous building materials/products, such as:
- Insulation
- Asbestos cement
- Roofing felt, shingles, and patch material
- Vinyl floor tile and linoleum backing
- Pipe and boiler insulation
- Fireproofing materials
- Spray-on decorative acoustic ceiling material
- And, putties, caulks, cement, and other masks
There are 2 general classifications of ACM’s, including:
- Friable Materials: Capable of being crumbled and reduced to a powder, when dry, using hand pressure
- And, Non-Friable Materials: Not easily crumbled or pulverized by hand pressure
Non-Friable ACM’s are not considered a health risk as the fibers are typically bound/contained in the building material.
Identifying Asbestos
Identification requires a combination of a visual inspection, understanding potential locations, and professional testing. Common locations, include insulation, flooring, texture coatings, adhesives, and asbestos cement sheeting. In addition, look out for the different types of asbestos, including:
- Chrysotile (White): This is the most common type and appears as a pale grey-white to grey-green color
- Amosite (Brown): Straight fibers and brown in color
- And, Crocidolite (Blue): Naturally long and sharp mineral form and blue in color
During a visual inspection:
- Look for fibrous materials: Asbestos can look like a soft, fluffy material or in the form of sheets or tiles
- Check for chalky texture: Cement siding and shingles containing asbestos may have a chalky texture
- And, inspect surface patterns: Many ACM’s have a swirl or dimpled surface pattern
If asbestos is identified on the job:
- Stop working and clear the area
- A certified expert will decide how to handle the situation safely and ensure worker exposure is kept as low as possible
- Limit access to locations where asbestos concentrations may be dangerously high
- Only allow a properly trained group to work with the asbestos. That group will take all required safety precautions including:
- Restrict access to the asbestos area and post warning signs
- Use respirators (not only dust masks) and full body coverings
- Wet down the asbestos to reduce dust
- Use power tools that have special exhaust filters
- And, receive regular medical exams
Exposure & Health Concerns
Exposure primarily occurs through inhalation of airborne asbestos fibers. When disturbed by breaking, drilling, cutting, sawing, or sanding, fibers can become airborne.
The primary route of exposure is through inhalation of fibers into the lungs. This can lead to cancer, scarring, or chronic inflammation.
The secondary route of exposure is through fluid ingestion. Ingestion of fibers is less likely to cause health problems than inhalation but still poses a risk.
The third route of exposure is dermal contact. This means fibers coming into contact with the skin but is unlikely to be absorbed.
Exposure can result in different types of health concerns, such as:
- Asbestosis: This means scarring on the lung tissues. Scarring impacts the elasticity of the lungs and lowers its ability to transfer oxygen and carbon monoxide. This is a slow progressing disease, taking anywhere from 15-30 years after exposure to fully develop
- Mesothelioma: This is a type of cancer. This disease attacks the lining of the space holding the lungs (pleura). Mesothelioma is exclusively related to asbestos exposure and can take anywhere from 30-40 years to develop
- And, Lung Cancer: This is a malignant tumor in the lungs. The tumor grows through the surrounding tissues, invading and blocking the air passages of the lungs. The time between exposure and the occurrence of lung cancer may take 20-30 years. There is a multiplying effect between smoking and asbestos exposure, which creates higher susceptibility to lung cancer
OSHA’s Asbestos Standard
OSHA sets out asbestos standards for both CFR 1910 and 1926. The following are a few major requirements listed in these standards:
- The Permissible Exposure Limit (PEL) of 0.1 fiber of asbestos per cubic centimeter of air as averaged over an 8-hour period, with an excursion limit of 1.0 asbestos fibers per cubic centimeter over 30 minutes
- Requirements for an initial exposure assessment to ascertain expected exposures during work operation, and periodic exposure monitoring in certain instances
- Use of engineering controls to meet the PEL. Where this is not possible, engineering controls must be used to reduce exposure to the lowest levels possible and then use respiratory protection
- Use of regulated areas to limit access to locations where asbestos concentrations may exist
- No smoking, eating, or drinking in asbestos regulated areas
- And, requirements for warning signs and caution labels to identify and communicate the presence of hazardous materials; recordkeeping and medical surveillance
Safe Handling Procedures
If workers handle or clean contaminated materials or dust, they shall follow these safety procedures:
- Wear appropriate personal protective clothing
- Thoroughly wet down the material prior to removal and regularly during work tasks by lightly spraying surfaces with water
- Use non-powered hand tools
- Minimize cutting or breaking asbestos cement products
- Remove and dispose of personal protective equipment after exposure
- And, perform personal hygiene practices
Note: Abatement procedures must be performed by qualified personnel only.
Conclusion
While asbestos played a significant role in construction for many years, its harmful health effects have made it clear that its use is no longer safe or acceptable. As we continue to uncover the risks associated with exposure, it’s essential for the construction industry to prioritize the safe removal and replacement of ACM’s in existing buildings.