Table 1: Sample Collection Breakdown
§All CPSC samples were unpainted drywall manufactured approximately between 2006-
They included the same brands that residents said were in their homes.
Sample collected from a home with domestic and imported drywall present.
Samples collected by the FLDOH were from homes that met the Florida case definition
of copper corrosion associated with imported drywall.
Based on the analytical results from this limited sampling event, the Technical Team believes that neither the imported nor domestic drywall tested pose a radiological concern.
As a result of recent speculation by consultants, homeowners, and the media about imported drywall containing phosphogypsum, the FLDOH and CPSC initiated a blind study of 21 samples of both imported and domestic drywall. CPSC initially submitted the samples to the FLDOH radiation laboratory, who after analysis forwarded the samples to NAREL for comparative testing. CPSC tasked this Technical Evaluation Team (Technical Team) to review the resultant EPA NAREL report: "EPA's analysis of Florida drywall samples and review of analytical results from the Florida Department of Health" (Appendix 1).
After receiving the EPA report, this Technical Team was provided CPSC sample identification information, and the analytical methods and the tabulated results from the FLDOH and NAREL laboratories. The sample identification information indicated which samples were imported (n=7) and which were domestic (n=13)3. This sample set included selections of imported drywall that homeowners reported to be installed in their homes. Seventeen of the 21 samples analyzed were drywall samples obtained by CPSC from domestic and imported manufacturers, and four were obtained by the FLDOH4 from homes with severe copper corrosion.
3 4 In addition, one sample was unmarked. Because of the small number of samples, the Technical Team cannot conclude that these samples represent all imported and domestic drywall nor that the results demonstrate statistical significance. However, the Technical Team notes that the approach used by FLDOH was to collect drywall from homes exhibiting the most severe signs of copper corrosion, odors and occupant complaints, and that homes with the most severe corrosion problems were assumed to have the strongest sources of corrosive gasses. Therefore, the Technical Team believes that this approach allows the results to be cautiously applied to homes with less severe signs of corrosion, odors, and occupant complaints.