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Reactive (Chinese) Drywall Assessment

Reactive Drywall, also known as Chinese Drywall, is known to release sulfurous gases. These emissions, which have the foul odor of rotten eggs, worsen as humidity and temperature rise. This causes copper surfaces to turn black and powdery, a chemical process indicative of a reaction with hydrogen sulfide. Copper pipes, wiring, and A/C coils are affected by this process. More importantly, these gases are a potential health hazard.


Homeowners afflicted by these gases have reported symptoms including irritated eyes and throat, coughing, sneezing, difficulty breathing, bloody noses, and symptoms similar to those of bronchitis and asthma. The greatest amount of Chinese Drywall was installed in the state of Florida, followed by Louisiana. Homes built or remodeled between 2005 and 2008 are considered most at risk.

Proper Detection

Proper detection of reactive drywall follows strict protocols guided by the Consumer Product Safety Commission and the Department of Housing & Urban Development. The identification process consists of two steps. A walk-through visual inspection by EE&G’s trained industrial hygienist’s checks for blackening on electrical wiring, air conditioning components and copper lines, and determines the year & origin of the drywall. If installed between 2001 and 2008, tests are performed on walls and drywall samples to confirm high levels of strontium, sulfur, sulfide compounds, and copper blackening.

Chemical-Free Solution

Once the reactive drywall is detected, EE&G offers a chemical-free solution to this devastating problem. Our experts use professional equipment to extract the odor from a home within 24 hours. We have serviced over 2,000 homes without a single failure, enabling homeowners to return to their homes and enjoy a safe, odor-free environment.


Drywall, also known as plasterboard, is a building material typically consisting of gypsum-based plaster extruded between two thick sheets of paper and kiln-dried.Drywall was imported by the United States during the construction boom between 2004 and 2007, spurred by a shortage of American-made drywall due to the rebuilding demand of nine hurricanes that hit Florida from 2004 to 2005, and widespread damage caused along the Gulf Coast by Hurricane Katrina in 2005.

An analysis covering drywall imports since January 2006 showed that more than 550 million pounds of Chinese drywall was brought into the United States since then, enough to build 60,000 average-sized homes. The green and red coloration in these copper components is an indicator that they were subject to typical corrosion, and not as a result of hydrogen sulfide emitted from contaminated imported drywall.

Homeowners alleging contaminated drywall

Homeowners alleging contaminated drywall have reported numerous incidents of corroding copper and other metals in their homes. The Florida Department of Health advised homeowners worried about tainted drywall to check copper tubing coils located in air conditioning and refrigeration units for signs of corrosion caused by hydrogen sulfide, as these are usually the first signs of the issue. Under normal circumstances, copper corrosion leaves it a blue/green or dark red color, whereas corrosion as a result of hydrogen sulfide exposure leaves a black ash-like corrosion. Homeowners who have verified that their home contains contaminated Chinese drywall are advised to replace any suspect drywall, as well as any potentially damaged copper electrical wiring, fire alarm systems, copper piping, and gas piping.

Potential Causes

Lab comparisons of Chinese- and American-made drywall show significantly higher levels of pyrite in the Chinese material. This suggests that pyrite oxidation may be the source of the sulfur compounds released by Chinese drywall.

The problems have been attributed to the use of fly ash in the drywall, which degrades in the presence of heat and moisture; although United States’ drywall uses fly ash as well, the process used creates a cleaner final product.

According to a 2010 laboratory study, one hundred percent of affected drywall samples obtained from homes located in the southeastern United States tested positive for the presence of Acidithiobacillus ferrooxidans, an iron and sulfur-reducing bacterium. Samples of non-contaminated drywall were found to contain only minuscule levels of A. ferrooxidans.

Forensic analyses suggest that disproportionation of elemental sulfur to hydrogen sulfide and sulfuric acid, caused by bacteria, was the primary cause of the malodors.

Potential health concerns

There are few studies exploring the effects of long-term low-level exposure to sulfur gases. However, it is believed that short-term exposure, over the period of a few hours, can result in a sore throat, eye irritation, cough, shortness of breath, chest pain, and nausea. Long-term exposure, over a period of weeks, is believed to cause chronic fatigueinsomnia, loss of appetite, dizziness, irritability, headaches, and memory loss.

The Center for Disease Control, in collaboration with the Agency for Toxic Substances and Disease Registry, released a guide indicating the residents of affected homes reported irritated and itchy eyes and skin, difficulty breathing, persistent cough, bloody noses, runny noses, recurrent headaches, sinus infection, and asthma attacks.