Bituminous Insurance Companies
Release Date: February 3, 2010
This is the fourth Engineering & Safety News Report highlighting developments in an ongoing Consumer Product Safety Commission (CPSC) interagency investigation. The CPSC published three reports highlighting their findings from a 51-home indoor air study, non-destructive evaluations, as well as preliminary electrical, and fire safety component corrosion study findings. The report summaries follow.
51-Home Indoor Air Study
The homes selected for the study were located in five states: Florida, Louisiana, Virginia, Mississippi, and Alabama. Ten non-complaint homes were selected from the same neighborhoods. A detailed survey of the characteristics of the homes included: measurement of drywall surface area, air exchange rate, temperature, indoor relative humidity, dew point, and identification of possible markers.
The report indicates there is an association between certain drywall and corrosion of metals in homes that were tested. The report indicates that the claim of reported health symptoms continues to be investigated. Investigating indoor air complaints in the homes posed challenges due to the low concentrations of contaminants found as well as the highly reactive nature of the chemicals of interest.
Some news reports focused on the presence of formaldehyde. Analysis revealed that the levels of formaldehyde and other aldehydes were comparable in complaint and non-complaint homes and consistent with expected levels in newly constructed homes.
Non-Destructive Evaluation Assessments
The assessment relied on non-destructive modes of determining the presence of imported, Chinese drywall. The following are various non-destructive assessments:
The preliminary findings indicate that the imported drywall does not pose a severe health hazard to occupants. The CPSC cautions that the studies are not conclusive and more analysis is required.
The initial investigation suggests a tiered approach to wide-scale assessment: visual inspection of ground wiring; use of XRF; deployment of passive monitors to measure specific gases; and metal 'coupons' to measure corrosion. To read Draft Indoor Environmental Quality Assessment of Residences report, click on http://www.cpsc.gov/info/drywall/51homeStudy.pdf.
Preliminary Electrical and Fire Safety Component Corrosion Study Findings
The corrosion on electrical components and fire safety components in homes was designed to address metallurgical analysis and accelerated corrosion testing to better understand long-term exposure implications. According to the report, there were no indications of significant overheating of conductors or conductive parts due to the corrosion events.
A total of 169 electrical components were selected from six homes. Seventy-three components were selected for analysis; six severely corroded receptacles were investigated in advance of the full study and then the remaining sixty-seven components from the six homes were evaluated. The analysis was performed to:
Using electron microscope imaging and chemical analysis of the observed corrosion on components, multiple forms of copper corrosion were observed. Two of the forms of corrosion were analyzed. The electrical component samples had visual signs of corrosion of copper wiring. Even so, there were no indications of significant overheating of conductors or conductive parts due to the corrosion events. Details of the analysis are available at: http://www.cpsc.gov/info/drywall/prelimelectrical.pdf
While the investigation is ongoing, the report suggests that most remediation efforts include the removal and replacement of electrical wiring and wiring devices. Copper wiring was observed to be most susceptible to the effects of corrosive gases. It was observed that metallic structures, such as switches or receptacles appear to be less sensitive to the effects of corrosion. The report outlines plans for long-term testing. The corrosion classification and accelerated testing studies are expected to continue until June 2010.
The Florida Department of Health (DOH) sponsored a technical symposium where testing protocols and resultant findings were shared amongst industry, homeowners, and governmental agencies. Proceedings from the Technical Symposium on Corrosive Imported Drywall are available at: http://www.drywallsymposium.com
What Is Next?
At this point, there are no conclusions, only preliminary observations. The CPSC findings revealed significant corrosion of copper wiring and lesser degrees of corrosion to other parts of the electrical components. The CPSC indicates that based on the findings, the next steps include developing a screening program to identify homes with affected drywall, and remediation methods to address the corrosive effects of the environment.
While the CPSC has been delving into the assessment and evaluation of remediation, the litigation community has been actively filing court papers. Cases were consolidated to Multi-District Litigation (MDL) in Louisiana federal court. The judge, Eldon Fallon, is to begin evidentiary hearings at the end of January 2010. The first hearing focuses on the scope and extent of appropriate remediation necessary for a number of properties, representing a cross section of properties at issue. More information is available from http://www.laed.uscourts.gov/drywall/drywall.htm.
Drywall Information Center materials are made available for online viewing by clicking on the following link: http://www.cpsc.gov/info/drywall/index.html. The CPSC released a December 2009 status update that can be found at: http://www.cpsc.gov/info/drywall/dec2009status.pdf.
The information contained in this publication was obtained from sources believed to be reliable. ISO Services Properties, Inc., its companies and employees make no guarantee of results and assume no liability in connection with either the information herein contained or the safety suggestions herein made. Moreover, it cannot be assumed that every acceptable safety procedure is contained herein or that abnormal or unusual circumstances may not warrant or require further or additional procedure.