Federal Government "Finds Strong Association" Between Chinese Drywall, Hydrogen Sulfide and Corrosion

The U.S. Consumer Products Safety Commission (CPSC) released a series of reports on November 23, 2009 that provide additional information from the ongoing investigation into problems associated with gypsum wallboard (drywall) imported from China and installed in certain U.S. homes. According to the executive summary accompanying the reports:

Released today is additional information from the investigation of problem drywall including the results from three preliminary scientific reports: a fifty-one home indoor air study; an electrical component corrosion study; and a fire safety component corrosion study.  Most significantly, the fifty-one home report released today finds a strong association between the problem drywall, the hydrogen sulfide levels in homes with that drywall, and corrosion in those homes.  The two preliminary component corrosion studies support this finding.  The fifty-one home study also provides some basic tools necessary for development of processes to identify and remediate affected homes, and advances the Interagency Task Force’s investigation to a new phase focused on these objectives. 

"The smaller sample (slightly gray in color) was taken from drywall which was removed from the home and replaced with new wallboard (white in color)."

The investigation is being conducted by the Interagency Drywall Task Force which consists of the Environmental Protection Agency (EPA), the Centers for Disease Control (CDC), the Department of Housing and Urban Development (HUD), Immigration and Customs Enforcement (ICE), the Agency for Toxic Substances and Disease Registry (ATSDR), and several state health departments. According to the Associated Press, "during the height of the U.S. housing boom, with building materials in short supply, American construction companies imported millions of pounds of Chinese-made drywall because it was abundant and cheap. An Associated Press analysis of shipping records found that more than 500 million pounds of Chinese gypsum board was imported between 2004 and 2008 — enough to have built tens of thousands of homes." Below is a summary of the findings to date:

• The study of fifty-one homes found a strong association between the problem drywall, the hydrogen sulfide levels in homes with that drywall, and corrosion in those homes. 
• While the study of fifty-one homes detected hydrogen sulfide and formaldehyde in homes containing the problem drywall at concentrations below irritant levels, it is possible that the additive or synergistic effects of these and other compounds in the subject homes could cause irritant effects.  The Interagency Task Force continues to investigate the nexus between the drywall and reported health symptoms. 
• The two preliminary studies of corrosion of metal components, taken from homes containing the problem drywall, found copper sulfide corrosion in the initial samples tested, which supports the finding of an association between hydrogen sulfide and the corrosion.  Ongoing laboratory tests continue to investigate the nexus between safety and the short and long-term effects of such corrosion. 

The next phase of the investigation is to identify affected homes and how to address both the drywall itself and any resultant damage, such as the corrosion of electrical, HVAC, gas distribution, and fire-safety components and/or indoor air quality. Preliminary data shows the possibility of two methods of detecting the problematic drywall within a structure. The first method involves placing coupons, or small strips of copper and silver, within a home for a certain period of time. Examination of the coupons indicate whether or not corrosive elements indicative of the imported drywall are present. Another method that has proven successful is through use of non-invasive handheld devices which provide X-Ray Fluorescence and Fourier Transform Infrared Readings (XRF/FTIR).

Number and Percentage of Reports by State