Hydrogen Sulfide (H2S) Health Hazards in Drywall
Application Note #AQ-13-719
Issue: Hydrogen Sulfide (H2S) discovered in Foreign–made Drywall
Since 2001, it is estimated that over 550 million pounds of foreign drywall (aka “Chinese Drywall”) tainted with H2S have been imported and used in the United States from approximately 2001-2007.
Origin of the Problem
New home construction surged in the first part of this decade. Domestic producers of drywall had difficulty meeting demand. This problem grew dramatically worse in the aftermath of Hurricane Katrina and soon, there was a major shortage of domestically produced dry wall. During the shortage, builders and contractors installed drywall manufactured in China from a variety of manufacturers. The gypsum rock (used primarily for drywall manufacturing) and the gypsum open pit mines in China contained very high sulfur contents. Under certain environmental conditions (typically warm, humid climates), the drywall will emit dangerously high levels of sulfur-bearing gases (H2S). These gases create an odor and corrode copper & other metal surfaces, which can damage your air conditioner, electrical wiring, copper plumbing, appliances and electronics. Chinese drywall can also cause serious adverse health effects. Starting in Florida in June 2008, homeowners started to complain to state authorities of a “rotten egg” or sulfur-like smell emanating from their homes. Complaints soon rapidly spread around the country.
|Element||Chinese Drywall||Domestic Drywall|
|H2S||83-199 ppm||< 1 ppm|
The NIOSH (National Institute for Occupational Safety and Health) Recommended Exposure Limit 10 ppm for 10 minutes
Recent Statistics and Examples
Since 2001, the U.S. Consumer Product Safety Commission has received approximately 3,952 reports from residents in 42 states regarding exposure to toxic drywall. It is also estimated that the tainted drywall have been used in over 300,000 homes. Homes built, rebuilt, or new additions using drywall from 2002-2007 are at the highest risk for containing toxic H2S gas. The H2S levels in these tainted drywall panels have been found to have over 100x greater H2S levels than domestically-made panels (see chart above). The chart above displays the distribution of reported drywall issues and the tested contaminant values. During periods of increased heat and humidity these panels will begin outgassing H2S and raise indoor level to a dangerous concentration.
Effects of H2S in Drywall:
- “Rotten Egg” smell, detected even at very low concentrations
- Sulfur corrosion of copper HVAC components
- Corrosion of electronics such as appliances, TV’s, and more
- Health ailments such as sore throat, asthma, difficulty breathing, and nausea
- The cost of remediating each home is tens of thousands of dollars, not including losses to personal property
AQ Expert Indoor Air Quality Monitor
The measurement, display and data logging of toxic Hydrogen Sulfide commonly found in confined environments and tainted drywall can be performed using the E Instruments’ AQ Expert portable IAQ monitor. This specialized instrument utilizes a very accurate electrochemical sensor to precisely measure even extremely LOW levels of H2S in ambient occupied breathing environments.