LSU AgCenter offices are receiving an increasing number of calls about Chinese drywall. Unfortunately so far, questions far outnumber answers.

Here's what we know about Chinese drywall:
Sulfur compounds including sulfur dioxide, hydrogen sulfide and carbon disulfide can form and be released into the air from some imported wallboard installed across the humid South between 2004 and 2008. These compounds can cause corrosion of copper, silver and other metals in home components such as air conditioners, exposed wiring, plumbing and electronics, thus raising serious safety, economic and health issues. Homeowners are also complaining about the smell of rotten eggs. Some are attributing a variety of respiratory and other health reactions to Chinese drywall.

Researchers in Florida, Louisiana and federal agencies are studying air quality in affected homes and testing drywall samples. They have yet to issue any specific health warnings. For now, we can offer no specific health recommendations other than to maintain adequate ventilation (for dilution) and to avoid adding moisture to indoor air because humidity and heat increase the release of sulfur compounds.

Chinese drywall was heavily imported because of shortages during the most recent housing boom and increased after the 2004 hurricane season. Researchers say enough drywall to build more than 60,000 homes was brought into the United States and used in Florida, Louisiana, Mississippi, Alabama and Texas. It is estimated that the amount of Chinese drywall brought into Louisiana post-Katrina could potentially affect approximately 7,000 homes.

Chinese drywall is identified by looking for the words "Made in China" on the back of the wallboard. Additionally, because these sulfur compounds corrode copper and silver, consumers and professionals can look for tell-tale signs, primarily a solid black patina on copper pipes, wires and air conditioner coils. Air conditioner evaporator coils are typically most affected because a large amount of air is drawn through them, and they are wet.

Because of the lack of scientific research and data about exposure levels, it would be unwise for LSU AgCenter agents to comment regarding health hazards of Chinese drywall. We do know that once corrosion manifests itself, the process is expected to continue for a long time. Thus, replacing air conditioner coils or other damaged metals should not happen until the source of the corrosion is removed and replaced.

The bottom line is that we have limited information for homeowners who believe Chinese drywall was installed in their homes. However, until acceptable, independent research is made public, we can and should discourage people from buying it and encourage people to evaluate their homes.

Consumers who suspect they have Chinese drywall in their homes or businesses are advised to use the following case definition to determine whether or not their home is affected. If their home meets this definition, they may contact the Louisiana Department of Health & Hospitals at 888-293-7020 and should consider remedial action.

Beware of Scams

At this time, there is no recommended air test or remedial treatment other than replacement of the Chinese drywall and any severely damaged equipment, exposed wires and metal components. Ozone generators and oxidizing (disinfectant) treatments are not recommended by EPA because they cause chemical reactions that can have other harmful effects or are not proven safe and effective. Homeowners should be cautious about the potential for scam artists selling expensive testing services or treatments. However, in the meantime, it may be helpful to take steps to keep conditions dry and cool, such as with air conditioning, dehumidification and exterior moisture control measures (good drainage, proper flashing, etc.)

Case Definition for Premature Copper Corrosion in Residences Possibly Associated with the Presence of Imported Drywall from China.

First, determine the date of construction. To meet the current case definition (03-30-09), homes constructed after 2003 (2004 to present) must meet two or more conditions, and those built prior to 2004 must meet three or more of the conditions specified below.

1. There is presence of sulfur-like or other unusual odors.
2. Confirmed presence of Chinese manufactured drywall in the home.
3. Observed copper corrosion indicated by black, sooty coating of uninsulated copper pipe leading to the air handling unit present in the garage or mechanical closet of home.
4. Documented failure of air conditioner evaporator coil (located inside the air handling unit).
5. Confirmation by an outside expert or professional for the presence of premature copper corrosion on uninsulated copper wires and/or air conditioner evaporator coils (inside the air handling unit).

By Steve Picou, Crescent Region Housing Agent, and Claudette Reichel, Professor and Housing Specialist

Sources:
Florida Department of Health
Louisiana Department of Health & Hospitals
Florida Palm Beach Post
WWL-TV
Miami Herald
MSNBC