A review of some definitions proves valuable in understanding the effects of changes in OSHA's asbestos standard on the roofing profession.

Due to the high tensile strength, incombustibility, corrosion/friction resistance, and thermal and acoustical insulation properties of asbestos, it has been an ingredient in over 3,600 commercial products since its mid-century introduction. It wasn’t until 1970 that OSHA identified the hazards and 1973 until the EPA promulgated the asbestos NESHAP rule to distinguish between friable and non-friable conditions.

In November 1990, the EPA revised its asbestos National Emission Standards for Hazardous Air Pollutants (40 CFR Part 61, Part M) altering, among other things, their applicability to friable and non-friable asbestos-containing materials. Then in August of 1994, OSHA and the National Roofing Contractors Association settled on a joint agreement clarifying the OSHA Asbestos Standard (29 CFR, Part 1926.1101) concerning incidental Asbestos-Containing Roofing Materials (ACRM). A review of some definitions (see sidebar) may prove valuable in understanding the effects of these changes on the roofing profession.

Typical ACRM

Some of the most common Category II ACRM include: corrugated, flat or laminated cementitious extrusion panels (30-50 percent), and roofing tiles and shingles (20-32 percent). Some common Category I ACRM include: smooth- and mineral-surfaced roofing felts (10-15 percent), asphalt shingles (1-5 percent), caulking putties (30 percent), cold-applied adhesives (5-25 percent), roofing asphalt (5 percent), mastic (5-25 percent), asphalt tile cement (13-25 percent), roof putty (10-25 percent) and fire sealants (50-55 percent).

Reviewing your company’s HazCom Program on an annual basis will enable your Competent Person (CP) to assess employee exposure to any ACRM. Obtain a copy of your commercial or industrial host employer’s Right-to-Know station concerning building materials that may be affected by your roofing project.

Incidental ACRM Compliance

The regulations concerning handling intact incidental ACRM became effective in July 1995. There are many other significant regulations applicable to Category II material removal that are not applicable to incidental ACRM work. There are five primary steps to complying with the changes to OSHA’s standard for handling incidental ACRM.

Pre-Job Inspection: A CP designated by the employer shall completely inspect the work site prior to exposing employees to any hazards, in order to determine that the ACRM is intact and will likely remain intact. Category I work sites require that appropriate hazard controls be implemented to protect workers from exposure. The minimum training requirements for Category II require that the CP receive an EPA-approved asbestos-supervisor training course.

Training: All potentially exposed employees shall be trained in specific task areas. Category I ACRM removal training requirements are not time-limited but must cover the site-specific hazards identified in a job safety analysis. The contents of this training should include: identification of asbestos and its uses in industry; physical characteristics and potential deleterious health effects; typical routes of exposure; relationship between cigarette smoking and asbestos exposure; a review of OSHA’s Asbestos Standard; recognition of characteristics of intact vs. non-intact materials; proper response procedures for non-intact exposure; and appropriate safe work practices for ACRM.

Category II Incidental ACRM removal jobs require the CP to attend an EPA-approved supervisor training course and the roofers to attend at least 8-hours of asbestos hazard awareness training.

Removal Methods: When removing Class I ACRM, employees must be trained, equipped and supervised by the CP in manual methods that do not render the ACRM “non-intact.” According to Part 1926.1101 (g)(11), alternate methods of compliance for roofing and pipeline coating prohibit sanding, abrading or grinding the material as a means of removal. OSHA’s definition of “non-intact” is identical to EPA’s definition of “friable.” Proper barricade tape and signage should be installed to identify the hazardous area.

ACRM such as cements, mastics, coatings and flashings, etc., are often found in far less quantities than the primary roofing shingles or built-up roofing and may be removed without incurring a severely hazardous exposure to roofers, or atmospheric discharge of fibers. Intact, manual removal of products that have a bituminous or resinous matrix may be done with such tools as axes, mattocks, pry bars, spud bars, crow bars, shovels or knives when they are used in a manner that prevents the material from crumbling or becoming pulverized. Failure to comply with these minimal standards will convert the operation to a Class II removal.

Material Handling: Incidental ACRM must never be dropped or thrown to the ground from the roof. It must be carefully packaged and lowered to the ground by means of a hoist, derrick, crane or fully enclosed, dust-proof chute. It may also be hand-carried or passed in such a manner as to prevent accidental loss of control. All ACRM should be removed from the area as soon as possible after being segregated from the roof, but no later than end of shift.

ACRM ground storage prior to hazardous waste removal shall be contained in the smallest area possible and clearly marked “Danger: Hazardous Material Storage” and controlled by adequate barricade tape. If during handling it is observed that the incidental ACRM has deteriorated to the point of becoming non-intact or friable, then it must be considered a potential for significant fiber release and reclassified as Class II removal.

Installation: Whenever employees are instructed to install ACRM (such as roof cement, mastic, roof coatings, etc.) on non-residential roofs, the employers must notify the property owner of the presence and location of these materials, at least by the end of the job. While these products are prepared by encapsulating the asbestos fibers in a bituminous or resinous compound to prevent accidental exposure, the CP must ensure the product is in the manufacturer’s original condition before application. This does not apply to any roofing product that is not labeled “asbestos-containing.”


Remember that the threshold criteria for “incidental” ACRM fall short of any roofing job in which asbestos is present in any concentration throughout the area and depth of the primary roofing materials, such as built-up roofing or asbestos-cement shingle roofs. These projects would clearly be classified as Class II removal sites and would require that the roofing contractor comply with the appropriate methods of compliance noted in 1926.1101 (g).

On a case-by-case basis, there are small roof leak repairs, short of replacement, where the necessity for Class II precautions are unnecessary. Repair of “intact” ACRM less than 25 total square feet (5-by-5 feet) does not require the use of wet removal methods or HEPA vacuum as long as manual methods of removal are used and no visible dust is created.

Take the time to clarify OSHA’s 29 CFR as well as EPA’s Title 40 to your job superintendents and designate the appropriate CP to act on your behalf on any site where potential asbestos-containing materials may be encountered. Adequate training in asbestos hazard awareness for all your personnel may prevent many potential illnesses and unnecessary downtime, as well as regulatory violations and penalties.


Asbestos: A name applied to a group of 6 different minerals occurring naturally in the environment (including the typical white as well as blue, gray and brown) made up of thin fibers (similar to fiberglass) 5 µm or longer with a length/diameter ratio of at least 3:1. Long fibers (>5µm) are more carcinogenic than short ones (<5µm).

Class I Asbestos Work: Activities involving removal of Thermal System Installation (TSI), Asbestos-Containing Material (ACM) or Presumed Asbestos-Containing Materials (PACM).

Class II Asbestos Work: Work involving removal of ACM that is not TSI or surface, including removal of wallboard, floor tile, sheeting, roofing, siding and/or mastic materials.

Class III Asbestos Work: Repair and maintenance operations where ACM or PACM is likely to be disturbed.

Class IV Asbestos Work: Maintenance and custodial activities where employees may contact but not disturb ACM or PACM and clean-up activities after Class I, II and III work.

Asbestos-Containing Waste Material (ACWM): Any waste material containing commercial asbestos generated by a source regulated by the National Emission Standard for Asbestos. These may include filters from control devices, friable asbestos material, packaging contaminated with asbestos, demolition products containing asbestos and contaminated disposal equipment, material and protective clothing.

Friable: Any ACM containing more than 1 percent asbestos as determined by polarized light microscopy (PLM) which, when dry, can be crumbled, pulverized or reduced to powder by hand.

ACWM, Category I: Non-friable ACM such as asbestos-containing packings, gaskets, floor coverings and asphalt roofing products containing more than 1 percent asbestos by volume using point counting by PLM.

ACWM, Category II: Non-friable ACM excluding Category I material, which have more than 1 percent asbestos by PLM point count, but which, when dry, cannot be crumbled, pulverized or reduced to powder by hand pressure.

Asbestos-Containing Roofing Material (ACRM): This class of ACWM is generated by either new roof construction, existing renovations or repairs, including intact roof cements, mastics, coatings or flashings (Category I) or built-up roofing or asbestos-cement shingles (Category II).

Incidental ACRM: Any ACRM that is typically encountered in conjunction with normal roofing operations, but removal of which is not the main task objective or primary scope of work.

Regulated Asbestos-Containing Material (RACM): 1)Either friable or non-friable Category I ACM that has become friable or 2) Category I materials that are subject to sanding, grinding, cutting or abrading or 3) Category II non-friable ACM that have a high probability of becoming friable in the course of demolition/renovation.