Oregon OSHA Construction Depot

Safety and health newsletter for the Oregon construction industry

September 17, 2013

In this issue:


Health hazards in construction: part 2

Asbestos removal

Asbestos: 1926.1101(f), Exposure assessments and monitoring

In Oregon, construction industry employers receive more citations for violations of lead, asbestos, hazard communication, and respiratory protection standards than other health standards. Typically, one or two paragraphs in each standard account for many, if not most, of the violations.

In part 2 of this series, the Construction Depot explains the requirements of 1926.1101(f) – Exposure assessments and monitoring in the Asbestos standard, requirements that are often overlooked by contractors who do renovation and remodeling work.

Most construction-industry employers know about asbestos and its health effects, but many forget to test for it on projects where it could be present. Since it's impossible to identify asbestos just by looking for it, the only way to know if asbestos is in building materials is to test for it. Typically, asbestos is found in installed products such as shingles, floor tiles, cement pipe and sheet roofing felts, insulation, ceiling tiles, and fire-resistant drywall.

Oregon OSHA's asbestos standard assumes that certain building materials (including thermal system insulation and surfacing materials) installed before 1981 contain asbestos; they are defined in the standard as presumed asbestos-containing materials – PACM. Employers must treat these materials as though they contain asbestos until they test them and the results show otherwise. Although it's more likely that asbestos is in buildings constructed before 1981, many products that can be bought legally today also contain asbestos.

The standard covers four classes of asbestos work:

Paragraph 1926.1101(f) states that before your employees do any work that could expose them to airborne asbestos, a competent person must measure their exposure levels and monitor their exposures. This initial exposure assessment is based on exposure monitoring results and any other information (including previous monitoring results) that might indicate employees are exposed to asbestos. The purpose is to give you information about your employees' expected exposure levels so that you can determine how to control their exposures if they are exposed at unsafe levels.

To do the initial exposure assessment, a competent person must take air samples representing employees' average exposures over an eight-hour shift in each work area, and take air samples representing employees' 30-minute short-term exposures in areas where they are most likely to be exposed to high levels of asbestos. The air samples must be taken from the breathing zones of each affected employee and a lab must determine how much asbestos is present in the samples.

If the lab results show that your employees are exposed to airborne concentrations of asbestos greater than 0.1 fiber per cubic centimeter of air averaged over an eight-hour shift (called the permissible exposure limit) or more than 1.0 fiber per cubic centimeter of air over the 30-minute period (called the excursion limit) you need to determine how to reduce their exposure below those levels. (Paragraph 1926.1101(g), Methods of compliance, covers control methods and work practices.)

If the lab reports that your employees are exposed below those levels, then the result is called a negative exposure assessment. In addition to lab reports, you can use "objective data" and "historical monitoring data" – if it's available – to confirm that your employees' exposures will result in a negative exposure assessment for specific jobs.

You must allow your affected employees to observe any exposure monitoring that you do.

For Class I and Class II work, you must conduct daily monitoring that is representative of the exposure of each employee working with asbestos, unless you have a confirmed negative exposure assessment for that work.

For work other than Class I and II, you must monitor your employees' exposures often enough to ensure that they do not exceed the permissible exposure limit. If periodic monitoring shows your employees' exposure levels remain below the permissible exposure limit and the excursion limit, you can discontinue monitoring.

Reprinting, excerpting, or plagiarizing any part of this publication is fine with us!

But remember: the information in this newsletter is intended to highlight safe work practices, but it does not replace Oregon OSHA workplace safety and health rules.

For information about Oregon OSHA services and answers to technical questions, call (503) 378-3272 or toll-free within Oregon, (800) 922-2689.