Federal investigators are now saying defective drywall manufactured in China and used to build homes in the Southeast during the housing boom is the cause of serious structural defects in a number of homes. “We now can show a strong association between homes with the problem drywall and the levels of hydrogen sulfide in those homes and corrosion of metals in those homes,” the US Consumer Product Safety Commission (CPSC) said in a statement (available to download here). The drywall has long been suspected of causing pipe corrosion and emitting toxic gases, but government agencies have shied away from publicly acknowledging the drywall is the cause of the problems until the claim could be scientifically proven. An inter-agency task force led by the CPSC and including the US Environmental Protection Agency (EPA), the Centers for Disease Control and Prevention/Agency for Toxic Substances and Disease Registry, and the US Department of Housing and Urban Development (HUD) as well as the Florida and Virginia health departments and the Louisiana Department of Health and Hospitals, among others recently completed tests on 51 homes and three preliminary reports were released detailing the effects of the defective drywall. According to the reports, hydrogen sulfide gas is the essential component causing copper and silver sulfide corrosion found in the affected homes, along with other factors, including air exchange rates, formaldehyde and other air contaminants. In ways still to be determined, hydrogen sulfide gas is being created in homes built with Chinese drywall, the report added, and the task force is investigating other non-Chinese drywall to see if they mimic the results found in the defective materials. More than 2,000 homeowners in 32 states contacted the CPSC with complaints of corrosion, or blackening, of indoor metals, such as electrical components and central air conditioning system evaporator coils and various health symptoms, including persistent cough, bloody and runny noses, headaches, difficulty in breathing and irritated and itchy eyes and skin. “We now have the science that enables the task force to move ahead to the next phase — to develop both a screening process and effective remediation methods. Ongoing studies will examine health and safety effects, but we are now ready to get to work fixing this problem,” said UCPSC chairman Inez Tenenbaum. The task force established a team of scientists and engineers to develop a cost-effective identification and remediation screening protocol for homeowners who believe their home may have defective drywall and is working with state consumer groups and federal officials to develop a plan of action to help homeowners. The drywall was manufactured and used in homes built between 2005 and 2007 and since the problems arose earlier this year, a number of initiatives were proposed to help homeowners with mortgages on defective homes, as well as legislation that would regulate standards for imported construction materials. While homeowners and builders look for recourse, a Fitch Ratings report warns it will be difficult to recovery losses from the foreign drywall manufacturers. Write to Austin Kilgore.