Research Highlights

NRMRL Research Team Tests Alternative Asbestos Control Method

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For decades, asbestos was widely used in the construction industry for its strength, fire resistance, and excellent insulating properties. But, in the 1970s, when scientists reported the negative health effects of inhaled asbestos fibers, the material was banned as a hazardous air pollutant. A silicate mineral made up of bundles of microscopic fibers that can become airborne when disturbed, asbestos has left a legacy of contaminated abandoned buildings, especially in older neighborhoods. Undisturbed asbestos poses little immediate health risk, but because demolition or rehabilitation of asbestos-contaminated buildings is likely to release fibers into the air, the process is closely regulated by national emission standards for hazardous air pollutants (NESHAP). Under current NESHAP rules, the costs of removal can be substantial—up to 60 percent of the total demolition costs of a building—and are a deterrent to the remediation or removal of many abandoned structures.

The Fort Chaffee project selected two buildings that were isolated from population centers and similar enough to give comparable data results. The first building was demolished using the existing (NESHAP) method, which requires the removal and disposal of the asbestos before demolition. A trained and certified crew of nine workers first hand-cleaned and sorted the asbestos, which was concentrated mostly in wall-joint compound and window glazing. The removal took nine days; following that, the demolition and removal took one day.

In the second building, the experimental (AACM) method treated the interior and exterior of the building with a chemical foaming agent, similar to a compound used by firefighters, to hold the asbestos in place as the building was being demolished. A surrounding earth berm retained the runoff. Demolition debris was loaded into plastic-lined trucks, sealed, and removed to an approved landfill. Two inches of soaked topsoil were also removed for disposal. The process took one day.

In both tests, air sampling stations monitored air quality before, during, and after the demolitions.  All workers wore protective clothing and respirators, but NRMRL researchers expect that the alternative method offered the better protection because workers did not have to work in the elevated asbestos conditions encountered using the NESHAP removal process.  Exact cost comparisons are not yet complete, but the cost of removing and disposing of the asbestos alone in the conventional method was an estimated $85,000, not including demolition and disposal costs.  The new method, based on findings from a similar experiment in another state, could save as much as 40 to 60 percent of the conventional costs.

	Jane Ice 513-569-7311, ice.jane@epa.gov

EPA Region 6 staff members who cooperated in the project stressed that this study by itself will not be used as a basis for revising the air toxics standard. Rather, the test data will become part of a baseline of information to use, if desired, in considering changes to current demolition standards. Final data analysis is expected to take several months. Because of the large number of asbestos-contaminated buildings on other military bases, the Department of Defense is expected to be particularly interested in the data generated by the test.