September 15, 2011
CPSC Completes Final
Studies to Help Affected Homeowners Remediate Problem Drywall
WASHINGTON, D.C. - The U.S. Consumer Product Safety Commission
(CPSC) and the U.S. Department of Housing and Urban Development (HUD) today
released updated remediation (pdf)
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
(pdf), fire sprinkler heads (pdf)
and smoke alarms
(pdf).
CPSC and HUD staffs believe these final studies that resulted in
an update of the remediation guidance, along with previously-issued identification guidance
(pdf), will enable homeowners to comprehensively remediate those homes
containing problem drywall with potentially lower costs than by following the
previous remediation guidance.
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. Corrosion of gas
service piping was uniform and minimal compared to the thickness of pipes. Some
smoke alarms and fire sprinkler heads showed small changes in performance due
to accelerated corrosion, but these changes were generally within accepted
industry standards.
As a result, CPSC and HUD no longer recommend the removal of gas
service piping in homes with problem drywall. This change may reduce the cost
of remediation for many homes. In addition, the agencies no longer recommend
that glass bulb fire sprinkler heads be replaced in homes. 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. The
agencies note that this type of sprinkler head is generally found in
commercial, rather than residential, applications and that the sole failure
could not be causally linked to the problem drywall.
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.
CPSC and HUD met with deeply-impacted homeowners, responded to
correspondence, and kept members of Congress informed about our progress during
this time period.
CPSC developed contracts to research and test problem drywall,
visited Chinese mines and manufacturers, hosted a public website to keep the
public informed about new developments, and devoted thousands of staff hours
and millions of dollars to these activities.
As part of the effort to determine if there were any health or
safety effects associated with problem drywall, the agency contracted with
several highly-respected technical organizations, including Lawrence Berkeley
National Laboratory (LBNL), Environmental Health & Engineering Inc.
(EH&E), Sandia National Laboratories (SNL), NIST, and the U.S. Geological
Survey (USGS).
LBNL used specially-built chambers to measure chemical emissions
from drywall samples. In the second phase of its work, which is being released
today, LBNL (pdf)
evaluated the effects of different temperature and humidity conditions, as well
as the effects of time and coatings of paint or plaster, on the emissions. A prior LBNL (pdf)
study found considerably higher hydrogen sulfide emission rates from some, but
not all, Chinese drywall samples compared to North American samples. The
current LBNL study found that increases in temperature and humidity
corresponded with increased emission rates of the most reactive sulfur gases,
that emissions were significantly reduced over time (compared with its prior
testing), and that coating the problem drywall samples did not result in
differences in emissions compared to uncoated samples.
EH&E conducted CPSC's 51-home study (pdf)
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.
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 being released today, that was conducted by the USGS
(pdf), 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.
As part of the investigation, CPSC requested that CDC consider
undertaking a comprehensive study of any possible long-term health effects. 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 reemerging. The standard setting body ASTM
International Inc. is also moving to require that all drywall sheets are marked
with the manufacturer's name or a unique identification code, the manufacture
date, and the source materials.
As the federal investigation into problem drywall concludes,
CPSC staff believes that the extensive research and testing have been
successful in defining the scope of the problem drywall issue, in producing
identification and remediation protocols, and in providing homeowners with all
the assistance possible within the agency's jurisdiction and appropriated funds
authority. The agency will continue to provide information to and work with
members of Congress and agency partners to support policy options that may be
beneficial to impacted homeowners.
For additional findings from the Interagency Drywall Task
Force's investigation, visit www.DrywallResponse.gov