Chinese Drywall Investigation
The chinese drywall investigation is proceeding simultaneously on three tracks: (1) evaluation of the relationship between the drywall and the reported health symptoms; (2) evaluation of the relationship between the drywall and electrical and fire safety issues in the home; and (3) the tracing of the origin and distribution of the drywall.
This investigation includes field work focusing on a number of issues. The staff is contacting some consumers to discuss their particular drywall issues and exploring their experiences in more detail. Some of these inquiries will be in person and some will be by telephone. We have field investigators permanently stationed in the affected States (with the exception of Wyoming) and we are shifting additional staff to those areas to assist in the investigation. Staff members are collecting samples of various drywall and degraded electrical components, and working to identify the links from foreign manufacturers to the U.S. consumers. One challenge has been figuring out how much problem drywall there is in any house, given that it is already installed, likely painted and may not be clearly marked. The drywall could fill the home or be just a few sheets.
Read about the chinese drywall lawsuit and frequently asked questions about Chinese Drywall.
The following offers some more detailed specifics about the health and engineering investigations to date.
Health Investigation
The most frequently reported symptoms are irritated and itchy eyes and skin, difficulty in breathing, persistent cough, bloody noses, runny noses, recurrent headaches, sinus infection, and asthma attacks. Since many consumers report that their symptoms lessen or go away when they are away from their home, but return upon re-entry, it appears that these symptoms are short-term and related to something within the home. Some of these symptoms are similar to colds, allergies or reactions to other pollutants sometimes found in homes. As such, it is important to carefully determine if the reported symptoms are related to the drywall and not any other environmental factors or pollutants in the home. We are aggressively investigating whether scientific evidence exists linking chemical emissions from the drywall to the reported health complaints. At this time, however, any such relationship or long-term health effects are unknown. We are undertaking a multi-tracked testing approach to assess the impact on human health. The data collected will form the basis for a health risk assessment.
- In-home air sampling (field) studies - Continuous, real-time measurements of the sulfur, acid and other gases, including the presence of freon byproducts. Measurements will take into account humid conditions as well as various times of day. Testing will be done over longer time periods because many symptoms have been reported to occur after hours of sleeping.
- Laboratory elemental characterization studies of domestic and imported drywall - Characterization of components of drywall and identification of any differences.
- Laboratory chamber studies of domestic and imported drywall - Chamber studies to separate and isolate chemical emissions from drywall as opposed to chemicals emitted from other home products (e.g., carpets, cleaners, paint, adhesives, beauty products).
Electrical and Fire Safety Investigation
Consumers have reported blackened and corroded metal in their homes. Particularly, consumers have reported failures of certain components such as: (1) premature failures of central air conditioning evaporator coils located indoors as part of the central air conditioning unit air handler; and (2) intermittent operation or failure of appliances, such as refrigerators and dishwashers, and electronic devices such as televisions and video game systems.
To date, CPSC has not received any reports of fire, electric shock or fire pre-cursor incidents (such as discolored, overheated/burned out, or smoking components) related to problem drywall.
Visual examination of electrical wiring within affected homes by CPSC staff showed varying levels of corrosion on the exposed portions of copper wires, in particular ground wires, since they are not insulated. The presence and extent of corrosion within a house, or even within a room, however, appeared inconsistent. We are investigating the electrical and fire safety issues in the home, including the corrosion of components such as fuel gas piping and fire safety devices, and any immediate or long-term fire and safety concerns. Particular areas of focus for this investigation include:
- Electrical components including residential wiring, receptacles, switches, circuit breakers, panel boards, ground fault circuit interrupters (GFCIs), and arc fault circuit interrupters (AFCIs).
Possible concerns with electrical components include:
- Deterioration of connections such as where a wire is connected to a receptacle or where a circuit breaker is installed in a panel board. A degraded connection could develop hot spots resulting in overheating and possibly fire.
- Erosion of copper conductors over time, reducing conductor crosssectional area and compromising its physical integrity. If the corrosion is progressively eating away at a wire, the wire would eventually lose its capacity to carry current and start to overheat or become physically weak and break.
- Damage to circuit traces or electronic components on printed circuit boards causing failure of protective devices like GFCIs, arc-fault circuit interrupters, and smoke alarms, which can present shock and fire hazards from the loss of protection provided by these devices.
- Gas service components including flexible connectors and copper piping. The concern is that potential gas leakage due to corrosive pitting of piping could present a fire or explosion hazard.
- Fire safety components including smoke alarms and fire sprinklers. For smoke alarms, potential concerns include damage to electronic circuitry and degradation of the sensor. Either condition could result in an inoperable smoke alarm. For fire sprinklers that use metallic fusible elements, potential concerns are that corrosion may adversely affect activation temperatures. Failures of these devices can put consumers at risk.
The investigation into electrical and fire safety issues is a two-part engineering component test program: (1) metallurgical analysis of various components collected from affected residences to characterize the type and extent of any damage; and (2) exposure of new components to elevated levels of gases, identified in the drywall chamber studies, as part of an accelerated corrosion test program to determine long-term exposure safety implications. A metallurgical analysis of the accelerated corrosion will enable comparison with the actual collected samples from homes.
