Chinese drywall is the general term used for drywall imported from China that releases volatile sulfur compounds into the air, particularly in warm moist climates. The volatile sulfur compounds, which have been identified as hydrogen sulfide, carbonyl sulfide, carbon disulfide, and several organic sulfur-containing compounds, have been linked to corrosion of copper and silver elements in buildings.

As of October 1, the Consumer Product Safety Commission has reported affected Chinese drywall in twenty-seven states, the District of Columbia, and Puerto Rico. In addition to the production of volatile sulfur-containing vapors, contaminated Chinese drywall has several differences from domestically produced drywall. All drywall, being primarily gypsum, or calcium sulfate dihydrate, contains sulfur.

However, the sulfur in calcium sulfate is nonvolatile. Our studies confirmed that affected Chinese drywall contains greater amounts of strontium and calcite and/or dolomite than domestic drywall. These differences are indicative of the source of the drywall and are likely unrelated to the production of volatile sulfur compounds. Chinese drywall samples have also been identified as containing elemental sulfur.

WJE scientists have analyzed Chinese drywall from multiple sources and compared their findings with several samples of domestically available drywall. We have characterized the drywall samples by a wide variety of techniques. These studies helped us understand the differences between affected Chinese and nonproblematic drywall as well as identifying markers or chemical or physical differences between the two that can be used to identify the source of the drywall, both in the field and in the laboratory. During these studies, WJE developed procedures and techniques for in-situ identification of Chinese drywall.