Statement from NORMI regarding Chinese Drywall 03/2009
This paper is being written with the intention of being a “living” document current to the date above but initially copyrighted as the date below. This document may be updated or revised as new and accurate information comes forth regarding this emerging issue. We have tried to collect only factual information to support our decision to recommend only removal and replacement of the offending drywall. Any other solution addressing relative humidity, air purification or encapsulates should be seen as temporary with only minimal positive effects.
Drywall now identified as “Chinese Drywall” appears to be offing a number of VOCs (volatile organic compounds) the primary of which is Hydrogen Sulfide (H2S) as a result of the manufacturing process and has been detected in drywall shipped to the US and received between 2004-2008 as a result of the high demand in the aftermath of multiple hurricanes. The current evidence shows:
• The levels of H2S are sufficient enough to corrode copper, brass, and some other metal building materials,
• The corrosion process may be accelerated by increased relative humidity in the indoor environment,
• There are varying degrees of other toxic compounds in the gypsum that may be as troubling,
• Homes may contain different amounts of drywall but a rule of thumb would suggest that a single family detached dwelling is likely to have the same drywall throughout the home where condos and multi-family building could have a mix of different kinds from different manufacturers,
• Approximately 13 manufacturing facilities in China could be involved,
• At least 550 million pounds of this drywall has been offloaded in at US ports since 2004 (one estimate suggests that this is enough to supply 250,000 average-sized homes however, this drywall was supplied to both single family detached and multi-family dwellings under construction.
• There is evidence that this drywall has been found in Florida, Arizona, Colorado, Georgia, Louisiana, Maryland, Nevada, New Jersey, New Mexico, North and South Carolina, Virginia, and Texas.
• Estimates be made that as many as 41 states may have found this drywall.
Health concerns vary, of course, but the municipalities and federal agencies have officially establish NO STANDARD for levels of H2S in indoor environments, therefore, it is unknown what might be considered a “Safe” level.
The corrosion that has been occurring to buildings appears to be seen as damage in the following ways:
• Noxious odors smelling like sulphur or “rotten eggs”,
• Corrosion of copper tubing, wiring, and water lines, as well as, some other metals (pics attached)
• Corrosion might also be seen in jewelry, chrome, and silver so plumbing faucets and drains might appear tarnished more quickly than normal,
• It has been reported that wiring in smoke detectors, televisions and other electronics may be affected due to the deterioration of lead soldering,
• Some nails and nailing plates may be affected.
A initial visual screening may be completed initially to determine if there is a reason to suspect the problem and then testing from a reputable lab (like EMSL) can take place to verify that what is suspected is, in fact, present. Only after documented proof from a qualified lab should a solution be implemented. There are no short-cuts and no methods currently available to test for these levels of VOCs outside of laboratory microscopy.
Our position is, therefore, that because off-gassing is occurring both INTO the living envelope (on the interior side of the drywall) and OUTWARD from the living envelope (into the cavity of the walls) there is no solution that will result in significantly reducing levels of this VOC (H2S) that does not include the entire removal and replacement of every sheet of defective drywall.
Any attempt to mask the odor or deal only with the interior envelope (or living space) should be seen as a temporary fix with no guarantee that the levels of H2S will be reduced or, if reduced, for how long.
D. Douglas Hoffman
Executive Director of NORMI
www.NORMI.org
www.NORMI.org
State releases findings of drywall investigationSouth Florida Business Journal - by Paul Brinkmann
ReplyDeleteChinese drywall samples give off sulfur gases and odor when exposed to extreme heat and moisture, according to a 60-page preliminary report released Monday by the Florida Department of Health.
The findings could explain why Florida’s hot, humid environment is an epicenter of the widening product liability crisis, said Dr. David Krause, state toxicologist, during a press conference Monday.
Drywall samples believed to have been manufactured in China showed a dramatic increase in sulfur gases when subjected to heat and humidity, while U.S.-made samples did not show as much of an increase, according to Krause.
Krause said the state’s new investigations confirm that sulfur fumes from defective drywall are causing metal corrosion in air conditioners and natural gas systems, which he said is cause for concern. He recommended homeowners worried about drywall problems contact their doctors, builders or maintenance professionals to evaluate any possible risks.
The new results do not help confirm or rule out health effects. The state is building a methodic scientific investigation that would take time, he said. Florida recently launched a new Web site focused on defective drywall problems.
Lab tests were performed by Unified Engineering, a private lab.
The lab tested one sample made in the U.S. by National Gypsum Co.’s GridMarx brand and three samples believed to have come from China, according to a letter that accompanied the results. However, only one of the three samples believed to be Chinese was marked as such.
“There is a distinct difference in drywall that was manufactured in the United States and those that were manufactured in China,” said Lori Streit, a principal scientist with Unified, in a letter. “The Chinese samples contained traces of strontium sulfide inclusions and more organic material that the GridMarx sample (United States). However, it is not yet known if either contributed to the odor.”
“It is clear that exposure to moisture accelerates the release of volatiles from the drywall,” Streit wrote. “Both the outer paper and the gypsum from the drywall had noticeable odors after moisture exposure and were found to release sulfur compounds.”
Krause said the test results of Chinese drywall showed only materials that would be associated with natural gypsum from gypsum rock mines.
“The presence of quartz and anhydite contradicts rumors that Chinese drywall was made from fly ash or from flue-gas-derived [synthetic] gypsum,” Krause said. Anhydite is a mineral frequently found in evaporite deposits with gypsum.
The Florida Department of Health is tracking 150 complaints about drywall causing metal corrosion in and odors in homes. The U.S. Consumer Product Safety Commission also is investigating the extent of the drywall problem.
Homeowners have filed lawsuits in recent months, claiming that the drywall has caused them to suffer health problems. It is also alleged to have cause corrosion of copper tubing used in air conditioners.