By Nick Gromicko and Kenton Shepard:
Amidst a wave of Chinese import scares, ranging from toxic toys to
tainted pet food, reports of contaminated drywall from that country have
been popping up across the American Southeast. Chinese companies use
unrefined “fly ash,” a coal residue found in smokestacks in coal-fired
power plants in their manufacturing process. Fly ash contains strontium
sulfide, a toxic substance commonly found in fireworks. In hot and wet
environments, this substance can offgas into hydrogen sulfide, carbon
disulfide, and carbonyl sulfide and contaminate a home’s air supply.
The bulk of these incidents have been reported in Florida and other
southern states, likely due to the high levels of heat and humidity in
that region. Most of the affected homes were built during the housing
boom between 2004 and 2007, especially in the wake of Hurricane Katrina
when domestic building materials were in short supply. An estimated
250,000 tons of drywall were imported from China during that time period
because it was cheap and plentiful. This material was used in the
construction of approximately 100,000 homes in the United States, and
many believe this has lead to serious health and property damage.
Although not believed to be life- threatening, exposure to high
levels of airborne hydrogen sulfide and other sulfur compounds from
contaminated drywall can result in the following physical ailments:
- sore throat;
- sinus irritation;
- dry or burning eyes; and/or
- respiratory infections.
Due to this problem’s recent nature, there are currently no
government or industry standards for inspecting contaminated drywall in
homes. Professionals who have handled contaminated drywall in the past
may know how to inspect for sulfur compounds but there are no agencies
that offer certification in this form of inspection. Homeowners should
beware of con artists attempting to make quick money off of this
widespread scare by claiming to be licensed drywall
inspectors. InterNACHI has assembled the following tips that inspectors
can use to identify if a home’s drywall is contaminated:
- The house has a strong sulfur smell reminiscent of rotten eggs.
- Exposed copper wiring appears dark and corroded. Silver jewelry and
silverware can become similarly corroded and discolored after several
months of exposure.
- A manufacturer’s label on the back of the drywall can be used to
link it with manufacturers that are known to have used contaminated
materials. One way to look for this is to enter the attic and remove
some of the insulation.
- Drywall samples can be sent to a lab to be tested for dangerous
levels of sulfur. This is the best testing method but also the most
Contaminated Chinese drywall cannot be repaired. Affected
homeowners are being forced to either suffer bad health and failing
appliances due to wire corrosion or replace the drywall entirely, a
procedure which can cost tens of thousands of dollars. This
contamination further reduces home values in a real estate environment
already plagued by crisis. Some insurance companies are refusing to pay
for drywall replacement and many of their clients are facing financial
ruin. Class-action lawsuits have been filed against homebuilders,
suppliers, and importers of contaminated Chinese drywall. Some large
manufacturers named in these lawsuits are Knauf Plasterboard Tianjin,
Knauf Gips, and Taishan Gypsum.
The Florida Department of Health recently tested drywall from three
Chinese manufacturers and a domestic sample and published their
findings. They found “a distinct difference in drywall that was
manufactured in the United States and those that were manufactured in
China.” The Chinese samples contained traces of strontium sulfide and
emitted a sulfur odor when exposed to moisture and intense heat, while
the American sample did not. The U.S. Consumer Safety Commission is
currently performing similar tests. Other tests performed by Lennar, a
builder that used Chinese drywall in 80 Florida homes, and Knauf
Plasterboard, a manufacturer of the drywall, came to different
conclusions than the Florida Department of Health. Both found safe
levels of sulfur compounds in the samples that they tested. There is
currently no scientific proof that Chinese drywall is responsible for
the allegations against it.
Regardless of its source, contamination of some sort is damaging
property and health in the southern U.S. The media, who have publicized
the issue, almost unanimously report that the blame lies with imported
Chinese drywall that contains corrosive sulfur compounds originating
from ash produced by Chinese coal-fired power plants. Homes affected by
this contamination can suffer serious damage to the metal parts of
appliances and piping and lead, potentially leading to considerable
health issues. While no governing body has issued regulations regarding
contaminated drywall, it is advisable that home inspectors be aware of
the danger it poses and learn how to identify it.
Warning: it is recommended that you DO NOT
hire an Inspector that cites any guidance issued by the U.S. Consumer
Product Safety Commission older than 3/18/2011 - it is possible that Inspectors using
outdated guidance issued by the CPSC could be placing consumers at risk.