November, 2011
Inspection News and Views from the American Society of Home Inspectors

CPSC Completes Final Studies on Problem Drywall


The U.S. Consumer Product Safety Commission (CPSC) and the U.S. Department of Housing and Urban Development (HUD) released updated remediation guidance for homeowners with problem drywall. The guidance calls for the replacement of all problem drywall; smoke and carbon monoxide (CO) alarms; electrical distribution components, including receptacles, switches and circuit breakers, but not necessarily wiring; and fusible-type fire sprinkler heads.

The updated remediation guidance is based on studies just completed by the National Institute of Standards and Technology (NIST) on potential long-term corrosion effects of problem drywall on select gas components, fire sprinkler heads and smoke alarms.

Key findings

The key finding is that none of the studies performed at NIST on smoke alarms, fire sprinkler heads or gas service piping found corrosion associated with problem drywall that provided evidence of a substantial product safety hazard, as defined by the Consumer Product Safety Act.

As a result, CPSC and HUD no longer recommend the removal of gas service piping in homes with problem drywall. However, the agencies recommend that both glass bulb sprinkler heads and gas distribution piping in affected homes be inspected and tested as part of the remediation to make sure they are working properly; any test failures should be corrected according to all applicable building codes.

The agencies do recommend the replacement of all fusible-type fire sprinkler heads, because one fusible-type sprinkler head sample that had been exposed to accelerated corrosion did not activate when tested.

In addition, CPSC staff continues to recommend that homeowners replace smoke alarms and carbon monoxide alarms as part of remediation.

Exhaustive investigation

CPSC's investigation into problem drywall to help affected homeowners began in early 2009 and involved significant agency resources. CPSC's investigation of problem drywall has been driven by sound science and has involved HUD, the U.S. Centers for Disease Control and Prevention (CDC) and the U.S. Environmental Protection Agency (EPA) as members of the Federal Interagency Task Force on Problem Drywall.

EH&E conducted CPSC's 51-home study on emissions and corrosion in problem drywall homes. The studies identified elevated levels of hydrogen sulfide in problem drywall homes. The studies also showed a strong association between the presence of hydrogen sulfide and metal corrosion in the problem drywall homes.

Sandia National Laboratories  (SNL) exposed smoke alarms, electrical components, gas piping and sprinkler heads to concentrated levels of gases representative of problem drywall emissions, to simulate decades of exposure. SNL analyzed the effects of corrosion on the electrical components and found no degradation in performance and no acute safety events during testing.

NIST analyzed the type and depth of corrosion resulting from the simulated aging, as well as other samples taken from homes with problem drywall, and evaluated whether the corrosion would impact the proper functioning of smoke alarms, gas distribution piping and fire sprinklers.

Another study that was conducted by the USGS found no evidence of microbiological activity or a microbiological source of sulfur-gas emissions from gypsum rock or problem drywall, including samples taken from affected homes.

In February 2011, CDC indicated that the best scientific evidence available at that time did not support undertaking a long-term health study.

Concluding Our Investigation

To date, CPSC has received 3,905 reports from residents of 42 states and the District of Columbia, American Samoa and Puerto Rico who believe their health symptoms or the corrosion of certain metal components in their homes are related to problem drywall. CPSC believes there may be as many as 6,300 U.S. homes with problem drywall.

CPSC has been focused on providing answers and guidance for homeowners based on its scientific work, and other federal agencies have worked to provide relief to homeowners. For example, based on information provided by CPSC, the IRS allows certain impacted taxpayers whose homes meet the CPSC's problem drywall identification criteria to treat damages from corrosive drywall as a casualty loss, and provides a "safe harbor" formula for determining the amount of the loss. In addition, HUD advised its Federal Housing Administration-approved mortgage lenders that they may offer forbearance for borrowers confronted with the sudden effects of damaging drywall in their homes.

Going forward, CPSC staff continues to work with voluntary standards organizations to develop improved standards for drywall to prevent this type of problem from re-emerging. The standard-setting body ASTM International Inc. also is moving to require that all drywall sheets be marked with the manufacturer's name or a unique identification code, the manufacture date and the source materials.


Remediation guidelines: drywall/Remediation091511.pdf

Press release from CPSC:

Findings from the Interagency Drywall Task Force's investigation: