A2 Technologies Hand Held FTIR analyzers are being used for on site testing for Chinese Drywall

Over 2,000 reports have been received by the United States Consumer Products Safety commission concerning indoor air quality from homes believed to contain drywall manufactured in China.  The suspect homes contain increased corrosion of pipes and wires; additionally, people living in those homes have reported a variety of adverse health affects.

The CPSC commissioned a 51 home study; the two goals of the study were to find the source of air quality issues and to find ways to determine if  a home contained Chinese drywall.  A report on the study can be found at this link: http://www.cpsc.gov/info/drywall/51homeStudy.pdf .  One of the technologies chosen for the study was A2’s Exoscan with a diffuse reflectance sample interface.  The study found that samples of Chinese drywall contained an elevated level of calcium carbonate which was readily detectable with the Exoscan.  This level of carbonate was much higher than levels found in domestic drywall.  It is believed that the carbonate is a marker for a process used to manufacture the gypsum; that process also produces a product with high levels of hydrogen sulfide which is believed to be the source of air quality issues. 

The CPSC study recommended that two measurements be made to determine if a home has Chinese drywall: measurement of calcium carbonate by diffuse reflectance infrared  spectroscopy and measurement of strontium by XRF spectroscopy.  Measurement of the two markers together reduces both false positives and false negatives.  The Exoscan or Flexscan with a diffuse reflectance interface provides an easy and sensitive means for measurement of the drywall on site.  In fact, the Exoscan was used for the CPSC study, establishing the pass/fail limits for this analysis.