Common Sources

Asbestos is a group of naturally occurring minerals. It's fibers are incredibly strong and have properties that make them heat resistant. The three most common types of asbestos are:
 

a) chrysotile
b) crocidolite
c) amosite
 

The material was most commonly used in building construction for...
 

• Heating pipe, duct and vessel insulation (The material was often blown onto structural beams and ceilings for insulation).

• Flooring tiles and mastic adhesive. (Any 9"x 9" floor tile made prior to 1973 contains asbestos and most flooring installed before 1970 probably contains asbestos.)

• Exterior siding and interior ceiling tiles.

• Other materials such as joint compound, plaster, etc.
   

Health Effects

Exposure to "friable" asbestos can lead to:
 

Asbestosis - a lung disease caused when asbestos fibers are inhaled - exposure traps the airborne (friable) particles in the lung tissue.  Body defenses try to dissolve the fibers by producing an acid but the acid is ineffective due to the chemical resistance of the fiber.  The acid could eventually scar the surrounding tissue becoming so severe that the lungs cannot function. The latency period ( time it takes for the disease to develop) may be 25-40 years. 

Mesothelioma - a cancer of the outer lining of the lung (pleura) and/ or the lining of the abdominal wall   (peritoneum). The only known cause of this form of cancer is from asbestos exposure. The latency period for mesothelioma may be 15-30 years.

Cancer - caused by asbestos can increased the effects of lung cancer in cigarette smokers (by as much as 50%).  Asbestos can also cause gastrointestinal tract cancer.  The latency period for cancer may be 15-30 years.
 

Asbestos is not always an immediate hazard if maintained in good condition (non-friable) and left alone.  It is only when asbestos containing materials are disturbed or damaged that it becomes a hazard. Asbestos is made up of microscopic bundles of fibers that may become friable. The term ‘friable’ is used to describe asbestos that can be reduced to dust simply by hand pressure. The fibers separate and could become airborne hanging in the air for days. Non-friable materials (e.g. transite siding, floor tiles, etc.) are not regulated by the State provided they do not become friable. Machine sanding, grinding, ripping, extreme vibration, and dry-buffing are likely ways of causing non-friable materials to become friable.

Testing

The only way to determine if a building contains asbestos is to have bulk samples tested by a Licensed Inspector who will send the materials to a certified laboratory.  New OSHA regulations require property owners to presume that suspect materials are asbestos until a laboratory analysis is completed.

Control/Remediation

The best solution for dealing with asbestos in good condition and well encapsulated (sealed) is to leave it undisturbed. There is no law that says asbestos has to be removed. Only when the material can no longer be maintained in good condition,  becomes friable, or the building is to be demolished or renovated may removal be the only option.

Federal law requires any building owner who is renovating or demolishing to have their building surveyed for asbestos. The structure cannot be demolished if  "friable" asbestos is present. Public and private schools, K-12, are required to be inspected by AHERA (Asbestos Hazard Emergency Response Act) and to have a management plan prepared/available for public inspection. 

Contact your local environmental waste management group before removing asbestos for advice/guidelines about safety, required paperwork/permits, and dump sites.   Generally, asbestos must be wrapped in 4 or 6-mil plastic, clearly labeled, and taken to a designated waste site. Large projects may require a project design. 

Encapsulation or abatement

Any old material you might suspect should be treated as if  it does contain asbestos. Significant deterioration, ceiling panels, and pipe wrap should be handled by a professional.
 

• In small, confined areas, asbestos dust is particularly harmful and a respirator mask (dusk masks are not adequate), gloves, disposable clothing and goggles are used. 

• Friable asbestos can be maintained in place utilizing several techniques. The area is first dampened with water to keep dust down and then sealed (encapsulated)  with heavy 4-6 mil plastic or a  type of  masonry, chemical, paint, or fabric hardcoating that will prevent the escape of friable particles. (Encapsulation is simply applying a thick layer of an encapsulant to bind the surface of the material together). Some areas may be caulked or patched using duct tape. You should consult an area specialists for proper materials to be used.

• When finished, dispose of clothing or seal your work clothes in a bag and wash them separately.

• For asbestos floor tiles, the safest solution to contain the asbestos is to cover with new flooring. If  flooring  must be removed, do not create dust by sanding but use a hand scraper and mist the area to minimize dust.

• The removal of pipe insulation via a glove-bag or a mini-containment and other abatement techniques are generally conducted following procedures outlined by the Department of Labor’s Rules for the Abatement of Friable Materials.
   

For large projects, a containment area will need to be constructed to seal off all entries and exits to prevent air from escaping. The containment area is maintained under negative pressure with the air exhausted through special filters. A decontamination unit is also constructed for workers to change into disposable suits and respirators upon entering and shower when exiting so not to contaminate the outside area. 

Upon approval, the material/structure is wet down (to reduce the airborne fiber count) and asbestos is scraped from the surfaces, collected, then double bagged and sealed in special disposal bags where they are then stored in specially lined waste trailers.  When the Inspector is satisfied with the cleanliness of the containment, the entire area is sprayed with a ‘lock-down’, which seals any remaining fibers - and those not visible - to the poly. When clearance monitoring is completed and air counts are within accepted levels, the containment is removed and the remaining poly is bagged and disposed of as contaminated waste.

Exposure Guidelines

Researchers have not yet determined what the "safe level" of exposure is but it is known that the longer the exposure, the greater the risk. Generally, any material that contains less than one percent asbestos is considered non-regulated. 

The Department of Labor oversees the regulation of asbestos problems.  If you would like a copy of the Rules, Licensed Contractor’s List or to become a Licensed Contractor, you may call the Asbestos Division at (405) 528-1500, ext. 250. To obtain a worker’s, supervisor’s, Inspector’s, Management Planner’s or Project Designer’s License, contact the Licensing Division at ext. 240