Due to its strength, inability to burn and insulating properties, asbestos was popular as a building material from the early 1900s through the 1970s. Asbestos is a naturally occurring mineral mined from the earth. Where other rocks typically break down into granulars, asbestos breaks down into fibers. Asbestos is believed to have been used in over 3,500 products.

The U.S. banned the production of asbestos containing materials in the 1980s; however, the importation of such materials was not banned. Consequently they are still on the market.

An EPA study of new materials going into school buildings during new construction and renovations found that 85% of the new materials were asbestos containing.

Material classification categories

  • Surfacing

    • Any material sprayed or troweled on

    • Acoustical or decorative plasters

  • Fireproofing

    • Thermal System Insulation

    • Used to inhibit heat transfer or prevent condensation

  • Miscellaneous (all other materials not categorized as TSI or Surfacing)

    • Floor tile, ceiling tile

    • Roofing felts, tars and shingles

    • Cement piping, siding, or shingles

 

Types of Asbestos

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Chrysotile

Most common type found in U.S.

Accounts for 95% of all asbestos materials

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Amosite

Second most common type found in the U.S.

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Crocidolite

The least common type found in U.S.

Most dangerous type to be exposed to due to link to mesothelioma

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Tremolite, Actinolite & Anthophyllite

These are rarely founds types of asbestos

Usually are found as contaminants of other asbestos containing materials

 

Health Effects

A dry material that can be crushed into powder by hand pressure is considered friable. This friable condition can result in the fibers becoming airborne and when airborne the fibers become a health hazard.

  • Fibers cannot be seen, tasted or smelled

  • Fibers are only visible under a microscope

  • Due to their aerodynamic properties the fibers can remain airborne for long periods of time

  • Exposure produces no immediate side effects

    • Asbestos was popular in 1940’s, but workers didn’t see side effects until 1970’s

    • These workers didn’t know to wear protection

  • Primary route of entry: inhalation

  • Ingestion and injection were thought to be alternative routes many years ago

Asbestosis

  • Scarring of the lung

  • Reduces lung capacity

  • Key Symptom: Shortness of Breath

  • Latency Period: 15 to 30 years

Lung Cancer

  • Asbestos exposure is only one way to develop lung cancer

  • Key Symptom: Coughing up blood

  • Latency period: 30 years

  • Smokers who are exposed to fibers are 50-90x more likely to develop cancer

Mesothelioma

  • Rarest form of asbestos related diseases

  • Cancer of the chest lining

    • Key symptom: Extreme Pain

    • Spreads rapidly

    • Almost always fatal

  • Latency period: 30 to 40 years

  • No dose-response relationship

Regulations - OSHA & EPA

Together, these agencies established guidelines and work practices for removal activities. They specified engineering controls and personal protective equipment regulations to protect workers and occupants.

OSHA

  • Standards for asbestos established in 1970s after influx of negative health effects

  • Permissible Exposure Limits (PEL) of 0.1 fibers per cc of air for 8 hours.

  • Establishes PEL for 30 minutes of 1 fiber per cc

EPA

  • Asbestos Hazards Emergency Response Act (AHERA)

    • K-12 public and private schools

    • Must identify, inspect and maintain materials

    • 6 month surveillances

    • Triennial reinspections

      • Notify parents, teachers and students

      • Following abatement activities, air levels must be either <0.01 f/cc by PCM or <70 Structures by TEM.

  • National Emission Standard of Hazardous Air Pollutants (NESHAP)

    • Inspections prior to renovations and/or demolitions of buildings

    • Must notify state of all demolitions regardless of asbestos

    • Must notify state of renovations disturbing over 160 sq ft or 260 ln ft

  • In certain states, EPA has designated specific state agencies to enforce the regulations that have been established

    • These agencies monitor all asbestos projects in their respective states

    • They regulate the licensing of all asbestos inspectors, designers, supervisors, and workers