Chinese Drywall Pollution

Chinese drywalls are building materials imported from China (e.g., Knauf and other brands) that were used in up to a hundred thousand or more U.S. newly built or renovated homes (in the 2000’s, especially between 2004-2008). Some Chinese made drywalls (wallboards) were reported to be defective because (especially under higher temperatures and humidity) they appear to release sulfur gases with unpleasant rotten-egg odor (e.g., hydrogen sulfide - H2S, sulfur dioxide - SO2, carbon disulfide - CS2). Apart from their persistent odor, these gases may pose a health risk to homeowners and induce copper corrosion, affecting electrical and plumbing components and resulting in the malfunctioning of air conditioning and electronics systems. Basically, the homes may become uninhabitable and of little market value. Additionally, ceiling tile panes imported from China may display similar issues. The severity of the Chinese-made drywall (wallboard) issues may be huge, potentially reaching proportions similar only to the asbestos crisis. Basically, only since 2006, more than 550 million pounds of toxic Chinese drywall was imported in the U.S. (according to Sen. Nelson). Florida received the highest amount of imported Chinese drywall (approx. 60%), followed by Louisiana. According to Sen. Nelson (who initiated a recall of defective Chinese drywalls), in the recent three-to-five year period about 60 million pounds of Chinese drywall arrived in Louisiana, while 27 million pounds of Chinese drywalls were recorded in Mississippi. Homes with defective Chinese drywall were also identified in almost all other U.S. states.

How to Detect Chinese-Made Drywall

Many questions are raised along with the growing complaints from homeowners, as we are just beginning to understand the story of what may become one of the most challenging environmental problems affecting homeowners, builders, homeowner suppliers, manufacturers, plumbers, regulators (e.g. the Department of Health – DOH), environmental scientists, attorneys, or others otherwise associated with any of these categories. But what is the risk to us and our families and how can we determine if we are at risk? There are several things one can do in order to check if his/her home has or has the potential to have defective Chinese drywall:

• “Do-it-yourself” testing for the presence of Chinese drywall in general and also specific brands with reported problems (such as Knauf);
• Laboratory and analytical testing to be ordered at specialized environmental laboratories – mainly measuring the emitted sulfur gases (e.g., hydrogen sulfide) and/or copper corrosion.

What Should I Do if I Have Chinese Drywall?

Defective Chinese Drywall

Chinese drywalls are construction materials made in China that were imported in the U.S. due to the shortage of domestic supply of drywall materials during the housing construction boom of the 2000’s (especially after 2004 and reaching a peak in 2006 following the series of destructive Gulf Coast hurricanes). Drywalls are usually made of gypsum, which is calcium sulfate dihydrate (CaSO4 x 2 H2O). Gypsum is obtained from either natural minerals (e.g., from open pit mines) or synthetic materials such as fly ash (usually from coal power plants). Thus, based on its origin, gypsum may contain a series of trace components (e.g., metals, minerals such as pyrite, and organic matter) in various proportions, which ultimately dictates its properties and the potential for becoming defective or not. Additionally, the form of sulfur is very important: any sulfur present in other forms than the sulfate (which is the basic component of gypsum) may be less stable and could react with other elements to produce off-gassing (fumes with a rotten-egg smell). 

Observed Differences in Composition of Defective versus Non-Defective Drywalls

The main observed differences between the toxic Chinese drywall and U.S. drywalls (generally non-defective) are synthesized below.

Based on a recent U.S. EPA study (2009) which tested 2 potentially defective Chinese drywalls and 4 U.S. drywalls:

• Sulfur was found in the tested potentially defective Chinese drywalls (at 83 and 119 mg/kg) while it was absent from the tested U.S. drywalls (below the detection limits of 8.23 mg/kg);
• Iron was found at various concentrations in the tested potentially defective Chinese drywalls (1,390 and 1,630 mg/kg) as compared to the tested U.S. drywalls (841-3,210 mg/kg).
• Strontium was detected in the tested potentially defective Chinese drywalls in higher amounts (2,570 and 2,670 mg/kg) than in the U.S. drywalls (244-1,130 mg/kg)
• Two organic compounds associated with acrylic paints were found in the tested potentially defective Chinese drywalls only.
• The amount of total organic compound was higher in the tested potentially defective Chinese drywalls (except for one of the four tested U.S. drywalls).

Other studies (Rosen, 2009; EMSL, 2009; Columbia Analytical, 2009) pointed out that:

• Defective Chinese drywalls were reported to contain pyrite (FeS2), which is usually avoided in building materials due to the risk of collapsing.
• It has been reported that sulfur based fungicides were used in the imported potentially defective Chinese drywalls in order to prevent mold and bacteria growth during shipping. Fungicides were probably not used in U.S. made drywalls.
• Recently, the presence of naturally occurring allotropes of elemental sulfur in the defective Chinese drywalls has been reported.
• From a structural point of view, defective Chinese drywalls were reported to have a lower fiber content and variable air void sizes (but in general smaller in size) as compared to U.S. drywalls.

What we know now is this:

Q: What contributes to defective Chinese drywall?
A: Its chemical (presence of certain trace elements) and physical structure (fiber content &void sizes) + Environmental factors (especially climate)

Q: Do any factors influence or induce a drywall to be defective other than its composition and structure?
A: Yes, it was reported more in states with humid and hot climate (such as Florida and Louisiana)

Q: How can one know if a drywall can become defective if no effects are discernable at the current time?
A: Through laboratory testing in controlled conditions

Once a defective product is identified, homeowners should consult an environmental attorney. The environmental lawyer may decide which are the best options for damage recovery, including pursuing class actions or individual lawsuits.The Knauf brand was confirmed in some cases of defective Chinese drywall products. However, other Chinese brands may also be associated with defective Chinese drywall. This is why accurate brand identification is required. Additionally, due to the high reported variability of Chinese drywall problems, the production batch of the defective Chinese drywall may need to be determined, too.