History of Contaminated Drywall
During the construction boom at the beginning of this decade the construction industry experienced shortages of many construction materials and began to import products from around the globe. In the last year, we have begun to discover the ramifications of importing some of these products. The most talked about is Chinese-manufactured drywall containing high sulfur content and found to cause a threat.
As construction materials ran short, contractors began ordering materials from around the globe in an effort to meet demand. Cement from Brazil was being off loaded in Florida at a rate of 1 million pounds a day. Roofing materials were being imported from across the world. Drywall began streaming into the US from China. Further increasing the demand for imported goods was its low cost. Often, imported goods were able to compete with US produced products, even with the added costs of shipping.
This supply and demand issue set the stage for the introduction of Chinese-made Drywall into the US.
The Toxic Ingredient
In an effort to lower costs and increase production, some Chinese manufacturers began adding ‘Fly Ash’ and other ingredients to their products.
Fly Ash has nothing to do with buzzing pests - it is a residue of coal combustion and has been used successfully in the US for decades as an admixture in concrete design as a supplement for cement. The ash is added into concrete as a replacement for some of the cement making the concrete more affordable, while still maintaining structural qualities. Once the Fly Ash is integrated with the mix it hardens with the concrete and solidifies.
Coal contains a small percentage of sulfur and other minerals. When burned and consumed these minerals remain in the ash. When used in concrete mixes, the minerals do not escape when solidified. However, in the production of drywall, the use of Fly Ash does not result in solid form and can escape in the form of gases. These gases can be harmful.
First Indication
The first indication of potential toxic drywall problems began in Florida, Alabama and Virginia, which all experienced peak construction during the boom years from 2004 to 2007. It was not until August 2008 that the Environmental Protection Agency (EPA) was officially acknowledging the problem.
After an extensive investigation, the bulk of the known problems with tainted drywall was traced to a manufacturer called Knauf Plasterboard Tianjin Co. Ltd. Initially, the company refused to take any blame and said the contaminated drywall came from another unnamed company. As the problem grew and testing began, the company acknowledged that it had shipped some bad drywall, but identified a single gypsum mine in Tianjin, China, which is no longer being used as a material source. Unfortunately, early indications are that the problem may not be limited to just this mine or manufacturer.
The Toxins
The contaminated drywall has been found to contain significant levels of several chemicals believed to be harmful or damaging including:
- Iron disulfide
- Hydrogen sulfide
- Sulfuric acid
- Sulfur dioxide
- Carbon disulfide