Gypsum Board

Gypsum board, or drywall, is typically made with 100% recycled, unbleached paper facings that are bonded without adhesives onto a gypsum core. Mined gypsum is still widely used in gypsum board production, but recycled and synthetic gypsum increasingly contribute to production. Post-consumer recycled gypsum is mainly comprised of scraps from construction. Pre-consumer recycled content includes synthetic, or flue-gas desulfurization (FGD) gypsum, a coal-combustion byproduct obtained from stack scrubbers that remove sulfur from coal-fired power plant emissions.

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Listed in: Interior Finish & Trim

Products in Gypsum Board

CertainTeed Corporation
CertainTeed Corporation
DensArmor Plus and DensShield
Georgia-Pacific Building Products
Lafarge North America
Serious Energy

 

2.
May 3, 2012 4:14 AM ET

Response to John Walls
by Martin Holladay

John,
Here is some information from BuildingGreen.com to guide you:


"Chemically, the synthetic gypsum produced from power plant scrubbers is nearly identical to virgin gypsum that is extracted from gypsum mines. Drywall manufacturers recognized in the 1990s that they could reduce costs by switching to synthetic gypsum, and they’ve also been able to tout the environmental benefits of keeping this waste product out of landfills. Of the 21 drywall plants operated by USG (North America’s largest drywall manufacturer), nine use exclusively synthetic gypsum, and six use a blend of virgin and synthetic gypsum. Most of the drywall factories that have been built in the past ten years in North America are using synthetic gypsum.

"Heavy metal contamination has become a concern with fly ash from coal power plants—should we also be concerned about synthetic gypsum, another coal combustion byproduct? While fly ash is directly produced from coal combustion and physically removed from stacks, synthetic gypsum is produced using just one constituent of the flue gases—sulfur dioxide—so it has much less potential for heavy metal contamination.

"Nonetheless, the Healthy Building Network recently cited drywall plant emissions data suggesting that high mercury levels might occur in synthetic gypsum that comes from power plants burning high-mercury coal. More detailed studies and transparency are needed to address these concerns. UL Environment is developing a standard for drywall, ULE 100, that addresses—among other factors—mercury emissions. Low mercury emissions will earn a point toward different levels of green certification for drywall. While mercury emissions won’t be a “knock-out” criterion for drywall in ULE 100, the standard will put this issue on the table and force drywall manufacturers to address it.

"While we look forward to ULE 100, EBN still considers drywall made from synthetic gypsum to be safe, and we still consider this drywall to be a greener option than drywall made from virgin gypsum."

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"Synthetic gypsum has been implicated in the imported drywall scandal, but it’s unclear whether it’s actually causing the problems. A small-scale study performed by the U.S. Environmental Protection Agency (EPA) in May 2009 found that levels of sulfur and strontium in Chinese drywall taken from houses where complaints had been reported were much higher than those in drywall manufactured in the U.S., including samples of GP’s ToughRock purchased at a retail location near the EPA testing facility. The ToughRock that was tested did have high levels of several semi-volatile organic compounds. EPA did not speculate on what effect high sulfur, strontium, or organic compound levels may have on indoor air quality, or whether any of these chemicals are the source of the corrosion problems being seen in so many houses."

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"Fortunately, the industry is beginning to address these issues. Steps are being taken to develop an Environmental Product Declaration (EPD) for gypsum board (see "The Product Transparency Movement: Peeking Behind the Corporate Veil," EBN Jan. 2012). Although ULE's 2010 standard based on life-cycle analysis hasn't had the kind of adoption GreenSpec would like to see, many paths toward healthy building materials--and healthier gypsum board in particular--are being explored.

"Buyers can use market pressure to encourage this shift--and avoid including toxic building materials in your building projects--by following these steps:

* Choose domestic: Regulations in the U.S. maintain minimum safety standards for gypsum board, and domestic drywall has not (yet) been linked to the Chinese drywall debacle.

* Avoid waste: Look for gypsum products with post-consumer recycled content, and avoid waste during drywall installation at the construction site. GreenSpec lists domestic manufacturers that have made strides in post-consumer content.

* Avoid indoor air quality problems: Select Greenguard- or ULE-certified gypsum board to ensure a healthy interior. GreenSpec lists domestic manufacturers that are certified to indoor air quality standards.

* Specify inert products: Wet paper-faced drywall is a perfect medium for mold growth, making any biocides included in drywall for mold prevention just a Band-Aid. If you're serious about mold prevention, particularly in settings or locations (like the first floor in a flood-prone area), specify non-paper-faced drywall, like the fiberglass-faced products listed in GreenSpec.

"Keep your eyes open for new data in the drywall industry."

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1.
May 2, 2012 8:24 PM ET

Safe Drywall
by john walls

How can I be sure I'm not getting drywall with sulfur problems (like the Chinese stuff a few years ago), or from the US with mercury content (from coal fired boiler refuse), or whatever other bad stuff might be out there?


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