When is drywall a problem?
The bottom line
Some drywall (gypsum board) imported in the early 2000s can emit sulfurous gases, resulting in damage to copper wiring and pipes, as well as some human health effects. When wet, drywall can be affected by mold.
Prevention Tips
Always wear safety glasses, gloves, and a dust mask when working with drywall.
Choose domestic drywall. Regulations in the US maintain minimum safety standards for gypsum board.
Consider mold-resistant drywall; it substitutes a fiberglass mat for the paper facing used in traditional drywall.
Green board is often used in bathrooms and showers as a mold-preventative building material. Although it is less effective at preventing mold than mold-resistant drywall, it is usually less expensive.
This Really Happened
Case 1. A 10-month-old girl was in a walker in her home while drywall was being installed. Her mother saw that the girl had drywall dust on her hands and called her poison center. Following the poison specialist's instructions, she gave the child a bath and something to eat and drink. The child then vomited up a small piece of drywall. She tolerated oral fluids afterward and was fine when the poison center checked back the following day.
Case 2. A 3-year-old boy pulled a towel rack off the wall and got drywall dust in his eyes and possibly his mouth. His mother called their poison center, who advised her to flush his eyes and give him something to drink, which she did. When the poison center checked back with his mother later that day, the boy was not having any symptoms.
What is drywall?
Drywall (gypsum board) is used in North American construction as a faster, easier, and less expensive alternative to lath and plaster wall surfaces. Drywall is made of compressed gypsum (calcium sulfate dihydrate) and additives such as mica, clay, and resin. The sheets of compressed material are then sealed with layers of paper.
Drywall installation generates gypsum and silica dust, which are irritating to the lungs. Workers should wear personal protective equipment such as safety glasses, gloves, and dust masks when handling drywall. Drywall that has been damaged by water loses its strength and can grow mold.
What is “problem drywall”? Is it dangerous?
After very active hurricane seasons in 2004 and 2005, there was a shortage of US-made drywall to meet the sudden needs of new home construction and rebuilding. Some suppliers turned to importing drywall from China to meet the demand. It is estimated that enough drywall was imported from China to construct 60,000 homes. Unfortunately, some of the imported drywall was contaminated with toxic chemicals.
In 2008, homeowners (mostly in Florida and Louisiana) began reporting upper respiratory irritation in their recently built homes. Many reported a decrease in symptoms when they left their homes and a recurrence of symptoms upon returning. Reported symptoms included headaches, irritated and itchy eyes/skin, difficulty breathing, persistent cough, runny nose, sinus infections and congestion, sore throats, frequent nosebleeds, and asthma attacks. Some residents reported a strong sulfur smell and premature corrosion or deterioration of certain metals (especially copper) in their homes, such as air conditioner coils and electrical wiring. Microbial conversion of excess sulfur in the dry wall to sulfuric acid and hydrogen sulfide is the most likely mechanism for the corrosion and odor.
How to identify “problem drywall”
The US Consumer Product Safety Commission (CPSC) defines "problem drywall" as meeting these criteria:
Step 1. A visual inspection must show blackening of copper electrical wire or air conditioning evaporator coils (see below) and drywall installed between 2001 and 2009.
Step 2. Drywall installed between 2005 and 2009 must have at least 2 of the below. For installations between 2001 and 2004, at least 4 of the following conditions must be met:
Elemental sulfur in the drywall core*
Black copper sulfide on labels, grounding wires, or air conditioning coils*
Chinese markings on drywall
Elevated sulfide gas emissions from drywall*
Corrosion induced by drywall in test chambers*
* lab testing requiredIn late 2009, CPSC concluded that there was a "strong association" between Chinese drywall and corrosion of pipes and wires reported by thousands of homeowners in the US. In response to the Drywall Safety Act of 2012, CPSC developed standards for proper labeling (including origin) and sulfur content of drywall.
Blackened copper pipe (Photo courtesy of CPSC)
Blackened and corroded copper coils (Photo courtesy of CPSC)
Identifying and preventing mold on drywall
When typical drywall gets wet, there is a possibility that mold will begin to grow on it, digesting the wet paper covering. If the drywall is exposed, then the mold growth will show as a dark or even black stain. If the drywall is not exposed, such as behind tile in a shower, the damage will not be visible, and the mold can spread through the drywall to the supporting studs. Replacing moldy drywall is a major expense when repairing damage from a flood.
Best drywall for avoiding mold
There are 2 main types of drywall that should be used in parts of the home that are likely to get wet. Green board’s resistance to moisture and mold comes from a high wax content in the paper on its front-facing side. The back side is usually untreated paper. While more resistant than regular drywall, green board will eventually fail as a barrier if it gets wet enough.
Meanwhile, mild-resistant drywall uses a fiberglass coating instead of paper. It is more effective than green board at preventing mold growth; it is also more expensive. There is no such thing as completely waterproof drywall.
If drywall is swallowed or gets in the eyes
If you suspect someone has swallowed drywall, do not make the person vomit. Use the webPOISONCONTROL online tool to get immediate help, or call your poison center at 1-800-222-1222.
When drywall dust gets in the eyes, minor irritation, redness, or a scratch on the surface of the eye can occur. Serious eye injury is not likely, but the eyes should be rinsed immediately. Remove contact lenses and rinse with lots of room temperature water. For children, pour water onto the bridge of the nose and let it gently run into the eyes. Encourage blinking. After rinsing, use the webPOISONCONTROL online tool to get immediate help, or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.
For More Info
References
Public health implications of Chinese-manufactured drywall. US Agency for Toxic Substances and Disease Registry. May 2, 2014. Accessed February 25, 2025.
