Based on scientific study of the problem to date, HUD and CPSC recommend consumers remove all possible problem drywall from their homes, and replace electrical components and wiring, gas service piping, fire-suppression sprinkler systems, smoke alarms and carbon monoxide alarms. Taking these steps should help eliminate both the source of the problem drywall and corrosion-damaged components that might cause a safety problem in the home.
The CPSC advises consumers to exercise caution when contracting for testing and remediation.
To view the full text of the remediation guidance, visit the federal Drywall Information Center Web site and download a PDF here: www.cpsc.gov/info/drywall/guidance0410.pdf.
The executive summary of the April 2, 2010, release included the following overview.
Released today is additional information from the investigation of problem drywall including: (1) Interim Remediation Guidance; (2) results from a study of drywall emissions from the Lawrence Berkeley National Laboratories (LBNL); and (3) results from a study of sulfur-reducing bacteria in drywall from Environmental Health and Engineering.
• Interim Remediation Guidance: The Interim Remediation Guidance addresses possible safety hazards related to corrosion in drywall homes by (1) eliminating the source of the corrosion, the problem drywall, and (2) replacing building components for which drywall-induced corrosion might cause a safety problem. The guidance calls for the replacement of: all possible problem drywall; all fire-safety alarm devices (including smoke alarms and carbon monoxide alarms); all electrical components and wiring (including outlets, switches, and circuit breakers); and all gas-service piping and fire-suppression sprinkler systems.
• Lawrence Berkeley National Laboratories: LBNL measured in laboratory chambers the chemical emissions from 30 drywall samples. The top ten reactive sulfur-emitting samples were of Chinese origin. Certain Chinese samples had emission rates of hydrogen sulfide 100 times greater than non-Chinese samples. CPSC staff modeling based on these results shows that estimated concentrations of the reactive sulfur chemicals in the indoor air of a home that are predicted to result from the presence of the drywall can be approximately a factor of 10 times greater for certain Chinese samples than for the non-Chinese samples.
• Bacterial Study: Based on a limited preliminary study of ten drywall samples, there appears to be no difference in the presence or absence of sulfur-reducing bacteria between the imported Chinese drywall and U.S. domestic drywall samples tested, including Chinese samples found by LBNL to have some of the highest reactive sulfur gas emissions.
The Interim Remediation Guidance and the results of the study of sulfur-reducing bacteria contribute to the science and information available to consumers considering ways to address a home impacted by problem drywall. Additional information expected this summer, specifically the results of long-term corrosion investigations underway at Sandia National Laboratories and the National Institute of Standards and Technology, will likely permit refinement and better understanding of the remediation approaches to this issue.
The LBNL data released today find greater emissions of reactive sulfur compounds, including hydrogen sulfide, from certain Chinese drywall than non-Chinese drywall. Expanding on the earlier scientific findings of the Interagency Task Force, these studies support the preliminary conclusion that certain Chinese drywall emits reactive hydrogen sulfide at rates much higher than other, non-Chinese drywall, and that hydrogen sulfide has a strong association to corrosion in homes with problem drywall.
More information is available at www.cpsc.gov/info/drywall/index.html.