Dust in the Wind: EPA’s Vacuous Review of Coal Waste in Building Products

James Vallette | February 28, 2014 | Policies

New Research Available 9/1/2020

HBN has updated our research on drywall. Our recommendations on avoiding drywall containing FGD gypsum have not changed and are based on the increased environmental releases of mercury associated with its production. See our updated blog post on this topic for further details.

*This blog post makes the statement “FGD products emit mercury concentrations in the air at least 20 times higher than wallboard made with mined gypsum.” After a further review of the study cited by the EPA report we have not been able to confirm this statement.

The EPA’s ongoing review of coal combustion wastes’ regulatory status would seem like a great opportunity to explore essential questions about the safety of bringing coal wastes into a wide range of interior building materials. But, any hopes for that kind of investigation crashed to earth with the EPA’s new report, Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard (February 2014).

Instead, the report signals a return to the agency’s longstanding role as cheerleader for the coal ash industry.  In 2010, the EPA Inspector General said the agency needed to reconsider its promotion of coal power waste reuse, and get some facts. "We determined that risk information on EPA’s Coal Combustion Products Partnership website was incomplete, and that information on the website appeared to inappropriately endorse commercial products," wrote Inspector General Arthur Elkins Jr.

In response, rather than seek original knowledge with a watchdog's eyes, EPA relied upon industry-funded resources at every turn, from the title of its report (the term "encapsulated beneficial use" is an invention of the American Coal Ash Association), to the peer review of its overall methodology (three of the four reviewers are coal ash reuse proponents), to the studies EPA used to calculate risks.

Devoid of critical thinking outside the coal ash industry’s echo chamber, the agency's conclusion -- “EPA supports the beneficial use of coal fly ash in concrete and Flue Gas Desulphurization (FGD) gypsum in wallboard” -- has an air of inevitability.

EPA’s evaluation of concrete and wallboard is exceedingly narrow. It does not consider other types of products, such as ceiling tiles and carpets, that commonly incorporate fly ash or FGD wastes from coal power plants.(1) It looks only at the use phase, not the manufacturing, installation, demolition, and disposal of wallboard and concrete.

Industry jargon

The agency's report repeats the phrase “encapsulated beneficial use” as a mantra, hypnotically reinforcing a concept of encapsulation that is far more political than scientific. In fact, FGD products emit mercury concentrations in the air at least 20 times higher than wallboard made with mined gypsum* (and that’s just what industry-funded research has found). (2)

The term “encapsulated beneficial use” appears first in a letter from the American Coal Ash Association to then-EPA Administrator Lisa Jackson in 2010.  It reemerged as an official phrase, last year, in the very methodology that considers whether the industry's products made with coal waste pose risks to consumers.  By title alone, EPA signaled where this was headed.

Industry peer review

After drafting the methodology, it enlisted a panel of four reviewers.  The peer review panel selection process claimed to be “free from conflict of interest,” but it did not seek much input outside the coal ash industry echo chamber. Candidates had to demonstrate expertise related to “beneficial use of industrial materials,” knowledge of coal combustion residues, and “the underlying principles of risk screening analyses.”

The panel of four experts included three civil engineers, and one indoor air expert.  The civil engineers are all long-time promoters of “beneficial use” of various waste streams, including coal fly ash. Each of the engineers has published research that was funded by coal companies and associations, including The Southern Company and the Electric Power Research Institute.  Their expertise is primarily related to exterior environments (roadways, soils) and not interior environments.

To EPA’s credit, at least they had a peer review process for the methodology, however flawed. For the report itself, no external reviewers are identified, nor is such a process discussed.

My unsolicited review that follows focuses on EPA’s evaluation of FGD wallboard, not its evaluation of fly ash in concrete that raises a host of other questions.

Industry data

EPA’s methodology relies upon available literature, not original research. Of that available literature, the vast majority is industry-generated, including the most vital data of all.

In its very first step in considering risks to consumers from FGD wallboard, EPA quickly dispenses any concern about mercury releases to household dust while the wallboard is installed in a building. (3)

Its proof: a single, unnamed, document, as is explained deep in the report. Page 4 of Section 5: Results, Uncertainties, and Conclusions, reads: “One existing evaluation was found to be relevant to releases from FGD gypsum wallboard. Based on this evaluation, the evaluation did not retain releases to dust, ground water, and surface water for further consideration.” (emphasis added)

The report does not identify the study used to discount these releases, so it is not possible to evaluate the merits of this conclusion.  Nor does it explain why it would consider one study, rather than multiple ones, to be sufficient for discounting these major potential exposure pathways.  The absence of data does not equate to the absence of risk.

The agency not only rejects any consideration of exposure to dusts directly released by wallboard, it also fails to investigate another pathway for exposure: the adsorption of mercury vapor, emanating from wallboard, onto interior dust particles and surface materials.  It fails to quantify the cumulative effect of sorption over time, for example in carpets upon which infants crawl. Instead, it presumes that all mercury in the air is mixed with outside air and leaves the building.

EPA’s compounds its failure of due diligence as it progresses through the methodology. In the final steps of its analysis, EPA estimates how much mercury would concentrate in indoor air from FGD wallboard. Its calculation depends entirely upon a mercury “emanation rate” from a single study, which was funded by a wallboard manufacturer (Georgia Pacific), using samples provided by that manufacturer.

One rate, based on testing products from one wallboard factory, with the samples and the funding for the research all provided by the same manufacturer, for the most vital data point in its calculation should not be considered sufficient to evaluate the FGD wallboard industry as a whole. But that is the flimsy foundation for a conclusion that has enormous economic, environmental, and public health consequences.

The agency asserts: “Based on this comparison, exposures to mercury vapor emitted by FGD gypsum wallboard do not warrant further consideration for human receptors.”

In 2011, the EPA Inspector General said the agency “promoted beneficial uses of Coal Combustion Residues based on incomplete information, without knowing the risks associated with each type of beneficial use.”  That charge still stands, after this latest report.  The agency’s rush to absolve FGD wallboard products from further scrutiny in the absence of full and independent data betrays the essentially political nature of its conclusions.



(1) The report carries this disclaimer: “While fly ash and FGD gypsum may not be the only CCR or industrial material that may be beneficially used in concrete or wallboard, this evaluation does not address the beneficial use of other industrial materials. This evaluation also draws no conclusions about other beneficial uses of fly ash and FGD gypsum." (page 2)

(2) The introduction to the “Independent External Peer Review of the Preliminary Draft Report,” defines “Encapsulated beneficial uses” as “those that chemically bind or physically isolate CCRs in a solid matrix that prevents mobilization of the CCRs into the surrounding environment.”   This definition does not seem to square with “mercury emanation rates” from wallboard used in EPA’ subsequent evaluation of FGD wallboard that reveal a steady state airborne migration of mercury from the wallboard’s “solid matrix.”

(3) In Step One of its evaluation of FGD wallboard, EPA states that “Based on a review of the available literature.... (f)or FGD gypsum wallboard, the single potential release retained was to air.  The one Constituent of Primary Concern identified for this release was mercury.” (Page 13-14 of Section 1)