The Centers for Disease Control and Prevention has released the results of a study which it commissioned concerning formaldehyde levels in mobile homes provided to residents of the Gulf Coast affected by Hurricane Katrina in 2005. The trailers, which were provided by the Federal Emergency Management Agency to survivors of the hurricane, have been the targets of a series of lawsuits around the United States. See In Re FEMA Trailer Formaldehyde Products Liability Litigation, MDL No. 1873 (E.D. La.). CDC has been working with FEMA and other agencies to investigate possible levels of formaldehyde in the trailers and mobile homes.


The study was conducted by the Lawrence Berkeley National Laboratory in California, and concluded that the individual component parts of the trailers contained formaldehyde below federally regulated levels, but when combined, the formaldehyde level can rise higher than regulatory limits/industry standards. That is, in the study of four vacant trailers, CDC’s contractor found that the amount of formaldehyde given off by each trailer part was not higher than the limit set by the U.S. Department of Housing and Urban Development. The higher overall total “may be because” the trailers use more composite wood products, such as thin particleboard, than site-built or manufactured houses, have more composite wood products in a smaller space than site-built or manufactured homes, and/or let in less fresh air than does a site-built or manufactured house. The study found that the trailers had more wood paneling in a more constricted space than other homes. “These findings indicate that elevated formaldehyde levels are most likely due to a construction/design issue in the trailers,” said the report.

Berkeley scientists focused on commercially available trailers and models built custom for FEMA by four makers. Scientists tested formaldehyde levels inside trailers for one hour in the morning and one hour in the afternoon. LBNL then tested individual pieces of the trailer at the Berkeley, Calif. lab. for emissions from specific parts of each trailer, such as walls, floors, ceilings, tables and cabinets. Some 45 small material samples of wood products from the 4 units were collected to measure their material-specific emission rates for 33 compounds. Only three of the compounds tested for were detected, and formaldehyde was the only one considered to be of possible human health significance. An important finding was that only one material of the 45 tested exhibited formaldehyde emissions in excess of the HUD standard.


CDC said the study helped identify the sources of formaldehyde and other volatile organic compounds that may make the largest contributions to the indoor air quality. It also indicates that the amount of ventilation affects the concentrations found in the air. However, MassTortDefense notes that the study analyzed only 4 vacant, never-used trailers, which were provided by FEMA, including two trailers that were specifically designed to be used as temporary emergency housing and thus not commercially available. CDC admits that this study, because it only examined four travel trailers, did not provide results that could be applied to all FEMA-supplied travel trailers or to other types of temporary housing, such as park models or mobile homes. That will likely not stop plaintiffs from trying to misuse it in litigation.

Such studies can present significant challenges in litigation because they may have the aura of credibility associated not only with an “independent” testing facility but also the government agency which commissioned the study. Generally speaking, parties facing such studies will want to carefully analyze the study, with expert assistance, to detect any issues with methodology, data, conclusions or application to the facts in the case at issue. For example, this study did not compare trailers purchased “off the lot” by FEMA to those designed specifically for FEMA use. Such flaws can point the way to investigations defendants may undertake to properly and more fully address issues in the litigation.  Similarly, CDC admits that “the results of the LBNL investigation described in this report are not definitive.”   It would be arguably improper for plaintiffs’ experts to place more reliance on the results than the agency that commissioned the study. Finally, defendants facing such studies will want to carefully explore potential sources of bias or interest on the part of the agency or testing facility.