The chemical analysis of the drywall is suggested to determine and compare the elemental composition and physiochemical nature of the subject drywall to that of domestic drywall. The USEPA published a report based on the chemical analysis of the drywall made in China with that of the local/domestic US manufactured drywall. Following is a summary of the test results from that report:

• Sulfur was detected at 83 parts per millions (ppm) and 119 ppm in the Chinese drywall samples. Sulfur was not detected in the four US-manufactured drywall samples.
• Strontium was detected at 2,570 ppm and 2,670 ppm in the Chinese drywall samples. Strontium was detected in the US-manufactured drywall at 244 ppm to 1,130 ppm.  Total acid soluble sulfides were not detected in any samples.
• Iron concentrations of 1,390 ppm and 1,630 ppm were detected in the Chinese drywall samples and in the range of 841 ppm to 3,210 ppm for the US-manufactured drywall samples.  Additional drywall samples will be tested to determine whether the iron is present as oxide, sulfide or sulfate.