Asbestos

Origin and History of Asbestos

Asbestos is a naturally occurring term for a group of six different fibrous minerals (including chrysotile, amosite, and crocidolite). These minerals are valued for their exceptional properties: they are fireproof, chemically resistant, and have high tensile strength.

• Origin: Asbestos is mined from natural deposits in rock and soil globally.

• Start of Widespread Use: While it was used sporadically for centuries, asbestos usage boomed during the late 19th and early 20th centuries with the Industrial Revolution. Its use accelerated dramatically after World War II due to demand for fast, cheap, and fire-resistant construction materials.

• End of Widespread Use: The use of asbestos in the U.S. began to decline in the 1970s following increasing health concerns and initial regulations by the Environmental Protection Agency (EPA) and the Consumer Product Safety Commission (CPSC). However, a complete ban was never fully achieved. The most significant regulatory action was taken in 1989, when the EPA attempted a comprehensive ban, but it was largely overturned in court. While its use is severely restricted today, it is still not fully banned in the United States.

Uses in Buildings

Due to its insulating and fire-resistant properties, asbestos was incorporated into hundreds of building materials. Materials containing asbestos are broadly categorized as friable (easily crumbled and releases fibers) and non-friable (bound in a matrix, less likely to release fibers unless disturbed).

• Insulation: Thermal System Insulation (TSI) on boilers, pipes, ducts, and tanks (often found as pipe wrapping or spray-on insulation).

• Fireproofing: Sprayed on structural steel beams and columns.

• Flooring: Vinyl floor tiles and the mastics (adhesives) used to set them.

• Roofing: Roofing felts, coatings, and cements.

• Gaskets and Sealants: Used in mechanical systems, furnace ducts, and window glazing.

• Drywall and Joint Compound: Used to add fire resistance and strength to joint compounds until the 1980s.

• Cement Products: Asbestos cement siding and transite pipes (flues, vents, and piping) where it acts as a binder.

Presence in Modern Buildings and Laws

Current Presence

Asbestos is found in virtually all commercial and industrial buildings constructed before 1980, and often in materials installed up to the early 1990s. Even if a building was built after the 1980s, older replacement materials or pre-manufactured components (like certain heating equipment) may contain asbestos.

Prohibiting Laws (Regulation)

The use and handling of asbestos are primarily regulated in the U.S. by two key agencies:

• Environmental Protection Agency (EPA): Under the Toxic Substances Control Act (TSCA) and the National Emission Standards for Hazardous Air Pollutants (NESHAP), the EPA regulates its manufacture and processing. NESHAP specifies work practices for asbestos during demolitions and renovations to prevent the release of fibers.

• Occupational Safety and Health Administration (OSHA): OSHA's asbestos standards (29 CFR 1926.1101 for construction and 1910.1001 for general industry) regulate worker exposure.

Manufacturer Workarounds

Since a complete ban was never implemented, manufacturers legally get around using asbestos by complying with EPA regulations that only ban specific uses and limit the percentage of asbestos in certain products. For example, some chlorine and alkali manufacturers legally import and use asbestos diaphragm sheets. In construction, however, alternatives such as fiberglass, cellulose, and various mineral wools are now standard for insulation and fireproofing.

OSHA Requirements for Employee Safety

OSHA mandates rigorous protocols for handling asbestos to ensure the safety of employees engaged in construction, maintenance, and demolition activities.

Presumption and Testing

• Mandatory Assumption: For buildings constructed before 1981, OSHA requires that all thermal system insulation (TSI) and spray-applied or troweled-on surfacing materials be presumed to contain asbestos unless the employer has definitive evidence to the contrary.

• Pre-Disturbance Testing: Prior to any work that involves disturbing building materials, the OSHA standards require the employer (or building owner) to test the material for the presence of asbestos. This must be done by trained and accredited personnel using standardized methods like Polarized Light Microscopy (PLM).

• Purpose: This testing requirement is designed to prevent employees from being exposed to unknown values of asbestos. By identifying the material upfront, the employer can properly classify the material, determine the required engineering controls (e.g., negative air machines, glovebags), establish proper worker respiratory and personal protective equipment (PPE), and implement the mandated work practices to minimize fiber release. Failure to test and properly handle the material can result in severe fines and endangerment of workers.

ACM: Asbestos-Containing Material

ACM is the foundational term and is defined as any material containing more than one percent (>1%) asbestos by weight. This threshold is determined by an accredited laboratory using standardized testing methods, such as Polarized Light Microscopy (PLM).

• Significance: Once a material is classified as ACM, it must be treated, handled, and disposed of according to strict federal and local regulations (e.g., OSHA's CFR 1926.1101 and EPA's NESHAP). The specific handling rules depend on whether the ACM is friable or non-friable.

• Examples: Pipe insulation, boiler insulation, spray-on fireproofing, and some drywall joint compounds.

PACM: Presumed Asbestos-Containing Material

PACM is a critical safety designation used specifically under OSHA regulations to protect workers in older buildings. It stands for Presumed Asbestos-Containing Material.

• Definition: PACM refers to specific types of thermal system insulation (TSI) and surfacing materials found in buildings built before 1981, unless a professional inspection and lab analysis (such as PLM) confirms the materials do not contain asbestos (i.e., they are <1% asbestos).

• The Rule of Presumption: If you are working in a pre-1981 building and are tasked with disturbing TSI (like pipe wrap) or surfacing materials (like sprayed-on acoustic plaster), you must treat it as ACM (use high-level PPE, containment, etc.) until proven otherwise. This presumption is a legal requirement designed to prevent accidental exposure to unknown asbestos hazards.

• Key Distinction: PACM is a safety control measure that mandates the use of proper work practices and worker protection immediately, regardless of whether a sample has been taken or analyzed yet.

TSI: Thermal System Insulation

TSI stands for Thermal System Insulation. This is one of the categories of materials that OSHA specifically identifies as PACM in older buildings.

• Definition: Insulation used to inhibit heat transfer or prevent condensation on mechanical systems, such as:

  • Boilers and tanks.

  • Pipes and fittings (pipe lagging).

  • Ductwork (though fiberglass duct insulation is often non-asbestos).

• Significance: Due to the high historical use of asbestos in these materials, TSI in older structures must be managed under the PACM rule.

Surfacing ACM

While not strictly an acronym, Surfacing ACM is an EPA and OSHA classification referring to material that has been sprayed or troweled onto surfaces for fireproofing, acoustic, or decorative purposes.

• Definition: Includes spray-applied fireproofing on structural steel beams, cementitious or fibrous insulation on ceilings, and some decorative plasters.

• Significance: This material is often highly friable—meaning the fibers are easily released into the air when disturbed, posing a severe health risk. It requires the highest level of abatement containment and engineering controls.

Friable vs. Non-Friable (Categorization for Handling)

These terms define the material's potential to release hazardous fibers and dictate your abatement methods.

• Friable ACM: Any material that, when dry, can be crumbled, pulverized, or reduced to powder by hand pressure.

  • Risk: High. Fibers are easily released. This requires full containment, negative air, and the highest level of protective measures.

  • Examples: Damaged pipe wrap, spray-on fireproofing.

• Non-Friable ACM: Material in which the asbestos fibers are firmly bound in a matrix (e.g., cement, vinyl, resin) and cannot be easily crumbled by hand.

  • Risk: Low, unless the material is severely damaged, sanded, cut, or otherwise compromised. It becomes friable when subjected to such disturbance.

  • Examples: Intact vinyl floor tiles, asbestos cement siding, mastics. Abatement procedures for non-friable materials may allow for less restrictive controls, provided the material remains intact during removal.

Your adherence to these distinctions is the difference between safe, legal project completion and severe regulatory penalties.