Below is the latest from HUD & the CPSC about identifying if you have Chinese drywall in your home. Take note that the government went PC (politically correct) calling it "problem drywall" That's BS! Call it what it truly is-- and make the Chinese pay for it...
The U.S. Department of Housing and Urban Development (HUD) and the U.S. Consumer Product Safety Commission (CPSC) issued guidance on how to identify the presence of problem drywall in homes.
http://www.cpsc.gov/info/drywall/InterimIDGuidance012810.pdf