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Construction Hazardous Materials Compliance GuideAsbestos Detection, Abatement, and Inspection Procedures
By R. Dodge Woodson
Butterworth-HeinemannCopyright © 2012 Elsevier Inc.
All right reserved.
Chapter OneWhat Is Asbestos?
Asbestos is the name given to a number of naturally occurring fibrous minerals with high tensile strength, the ability to be woven, and resistance to heat and most chemicals. Because of these properties, asbestos fibers have been used in a wide range of manufactured goods, including roofing shingles, ceiling and floor tiles, paper and cement products, textiles, coatings, and friction products such as automobile clutch, brake, and transmission parts. The Toxic Substances Control Act defines asbestos as the asbestiform varieties of chrysotile (serpentine), crocidolite (riebeckite), amosite (cummingtonite/grunerite), anthophyllite, tremolite, and actinolite.
The term asbestos describes six naturally occurring fibrous minerals found in certain types of rock formations. It is a mineral compound of silicon, oxygen, hydrogen, and various metal cations. Of the six types, the minerals chrysotile, amosite, and crocidolite have been most commonly used in building products. When mined and processed, asbestos is typically separated into very thin fibers. When these fibers are present in the air, they are normally invisible to the naked eye. Asbestos fibers are commonly mixed during processing with a material that binds them together so that they can be used in many different products. Because these fibers are so small and light, they may remain in the air for many hours if they are released from the asbestos-containing material (ACM) in a building.
Asbestos became a popular commercial product to manufacturers and builders in the early 1900s to the 1970s. Asbestos is durable and fire retardant, resists corrosion, and insulates well. It is estimated that 3,000 different types of commercial products contain some amount of asbestos. The use of asbestos ranges from paper products and brake linings to floor tiles and thermal insulation. See Box 1.1 for key points about asbestos. Intact and undisturbed, ACM does not pose a health risk. Asbestos becomes a problem when, due to damage, disturbance, or deterioration over time, the material releases fibers into the air.
* ASBESTOS HEALTH EFFECTS
If inhaled, tiny asbestos fibers can impair normal lung functions and increase the risk of developing lung cancer, mesothelioma, or asbestosis. It could take anywhere from 20 to 30 years after the first exposure for symptoms to occur. Severe health problems from exposure have been experienced by workers who held jobs in industries such as shipbuilding, mining, milling, and fabricating.
Exposure to asbestos increases your risk of developing lung disease. That risk is made worse by smoking. In general, the greater the exposure to asbestos, the greater the chance of developing harmful health effects. Disease symptoms may take several years to develop following exposure. If you are concerned about possible exposure, consult a physician who specializes in lung diseases (pulmonologist).
Exposure to airborne friable asbestos may result in a potential health risk because persons breathing the air may breathe in asbestos fibers. Continued exposure can increase the amount of fibers that remain in the lung. Fibers embedded in lung tissue over time may cause serious lung diseases including asbestosis, lung cancer, or mesothelioma. Smoking increases the risk of developing illness from asbestos exposure.
The following are three of the major health effects associated with asbestos exposure:
Asbestosis—Asbestosis is a serious, progressive, long-term noncancer disease of the lungs. It is caused by inhaling asbestos fibers that irritate lung tissues and cause the tissues to scar. The scarring makes it difficult for oxygen to get into the blood. Symptoms of asbestosis include shortness of breath and a dry, crackling sound in the lungs while inhaling. There is no effective treatment for asbestosis.
Lung cancer—Lung cancer causes the largest number of deaths related to asbestos exposure. People who work in the mining, milling, and manufacturing of asbestos and those who use asbestos and its products are more likely to develop lung cancer than the general population. The most common symptoms of lung cancer are coughing and a change in breathing. Other symptoms include shortness of breath, persistent chest pains, hoarseness, and anemia.
Mesothelioma—Mesothelioma is a rare form of cancer that is found in the thin lining (membrane) of the lung, chest, abdomen, and heart, and almost all cases are linked to exposure to asbestos. This disease may not show up until many years after asbestos exposure. This is why great efforts are being made to prevent schoolchildren from being exposed.
* WHERE CAN ASBESTOS BE FOUND?
Asbestos fibers are incredibly strong and have properties that make them resistant to heat. Many products are in use today that contain asbestos. Most of these are materials used in heat and acoustic insulation, fire proofing, and roofing and flooring. In 1989, the Environmental Protection Agency (EPA) identified the following asbestos product categories. Many of these materials may still be in use. Table 1.1 provides examples of such products.
* WHAT SHOULD PROPERTY OWNERS DO IF THEY DISCOVER ASBESTOS?
The best thing to do is to leave alone any asbestos-containing material that is in good condition. If unsure whether or not the material contains asbestos, you may consider hiring a professional asbestos inspector to sample and test the material. Before you have your house remodeled, you should find out whether asbestos-containing materials are present.
If asbestos-containing material is becoming damaged (i.e., unraveling, frayed, breaking apart), you should immediately isolate the area (keep pets and children away from the area) and refrain from disturbing the material (either by touching it or walking on it). You should then immediately contact an asbestos professional for consultation.
It is best to receive an assessment from one firm and any needed abatement from another firm to avoid any conflict of interest. In such a scenario as described here, asbestos-containing material does not necessarily need to be removed but may rather be repaired by an asbestos professional via encapsulation or enclosure. Removal is often unnecessary.
The National Institute of Standards and Technology (NIST) maintains a listing of accredited asbestos laboratories under the National Voluntary Laboratory Accreditation Program (NVLAP). You may call NIST at 301-975-4016.
How to Identify Materials That Contain Asbestos
You can't tell whether a material contains asbestos simply by looking at it, unless it is labeled. If in doubt, treat the material as if it contains asbestos and have it sampled and analyzed by qualified professionals. A professional should take samples for analysis because the professional knows what to look for and because there may be an increased health risk if fibers are released.
In fact, if done incorrectly, sampling can be more hazardous than leaving the material alone. Taking samples if you are not trained in the proper procedures is not recommended. Material that is in good condition and will not be disturbed should be left alone. Only material that is damaged or will be disturbed should be sampled. Table 1.2 shows a timeline for asbestos regulations.
* MANAGING ASBESTOS PROBLEMS
If the asbestos material is in good shape and will not be disturbed, your best option is to do nothing. See Figure 1.1 for an example of shingles that are still in good shape. If the asbestos is a problem, there are two types of corrections. You can either repair or remove the asbestos.
Repair usually involves either sealing or covering asbestos material. This is a fairly common procedure when there is no immediate threat of asbestos exposure.
Sealing (encapsulation) involves treating the material with a sealant that either binds the asbestos fibers together or coats the material so fibers are not released. Pipe, furnace, and boiler insulation can sometimes be repaired this way. This procedure should be done only by a professional trained to handle asbestos safely.
Covering (enclosure) involves placing something over or around the material that contains asbestos to prevent release of fibers. Exposed insulated piping may be covered with a protective wrap or jacket.
With any type of repair, the asbestos remains in place. Repair is usually cheaper than removal, but it may make later removal of asbestos, if necessary, more difficult and costly. Repairs can either be major or minor.
Asbestos Dos and Don'ts for Homeowners
As a contractor who works with asbestos, you may need to educate potential customers as part of your job. This can be a good way to build a potential customer base. For example, you might offer a free seminar where you discuss the risks of asbestos and the proper procedures for property owners to adopt in an effort to avoid exposure to asbestos. The people attending your seminar may become customers.
At the very least, you will have brought the subject to light and educated the public in what to look out for and what to do if they suspect they may have a problem with asbestos. The following are some key topics that you should provide to property owners:
Do keep activities to a minimum in any areas having damaged material that may contain asbestos.
Do take every precaution to avoid damaging asbestos material.
Do have removal and major repair done by people who are trained and qualified in handling asbestos. It is highly recommended that sampling and minor repair also be done by asbestos professionals.
Don't dust, sweep, or vacuum debris that may contain asbestos.
Don't saw, sand, scrape, or drill holes in asbestos materials.
Don't use abrasive pads or brushes on power strippers to strip wax from asbestos flooring. Never use a power stripper on a dry floor.
Don't sand or try to level asbestos flooring or its backing. When asbestos flooring needs replacing, install new floor covering over it, if possible.
Don't track material that could contain asbestos through the house. If you cannot avoid walking through the area, have it cleaned with a wet mop. If the material is from a damaged area, or if a large area must be cleaned, call an asbestos professional.
Major repairs must be done only by a professional trained in methods for safely handling asbestos.
Minor repairs should also be done by professionals because there is always a risk of exposure to fibers when asbestos is disturbed.
Doing minor repairs yourself is not recommended because improper handling of asbestos materials can create a hazard where none existed.
Removal is usually the most expensive method and, unless required by state or local regulations, should be the last option considered in most situations. The reason is that removal poses the greatest risk of fiber release. However, removal may be required when remodeling or making major changes to your home that will disturb asbestos material. Also, removal may be called for if asbestos material is damaged extensively and cannot be otherwise repaired. Removal is complex and must be done only by a contractor with special training. Improper removal may actually increase the health risks to you and your family.
* ASBESTOS PROFESSIONALS
Asbestos professionals are trained in handling asbestos material. The type of professional will depend on the type of product and what needs to be done to correct the problem. You may hire a general asbestos contractor or, in some cases, a professional trained to handle specific products containing asbestos. Roofers are one example of such specialists, as shown in Figure 1.2.
Asbestos professionals can conduct home inspections, take samples of suspected material, assess its condition, and advise about what corrections are needed and who is qualified to make the corrections. Once again, material in good condition need not be sampled unless it is likely to be disturbed. Professional correction or abatement contractors repair or remove asbestos materials.
Some firms offer combinations of testing, assessment, and correction. A professional hired to assess the need for corrective action should not be connected with an asbestos-correction firm. It is better to use two different firms so there is no conflict of interest. Services vary from one area to another around the country.
Excerpted from Construction Hazardous Materials Compliance Guide by R. Dodge Woodson Copyright © 2012 by Elsevier Inc.. Excerpted by permission of Butterworth-Heinemann. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
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