How Green is Drywall Joint Compound?
USG suggested we write an article about new packaging for joint compound. We asked them to go deeper, and make a case the product is sustainable and safe. You decide if the company made its case.
USG: At the end of 2015, USG connected with finishers via social media about their favorite joint compound. The “What Color Lid Are You?” campaign spread like wildfire. Over 200 finishers engaged in conversation with USG to voice their opinions about various joint compound products.
Bad Idea: Representing contractors sanding joint compound without a mask is commonplace, and encourages risky work practices. Power sanders like this capture about 80-90 percent of the dust they toss.
Here are the results:
- 35% favor the blue lid because it has less shrinkage
- 33% prefer the green lid because of its smooth finish
- 14% favor the purple lid because it is perfect for all coats
- 9% prefer the lime green lid because it sands easily
Green Builder: We would love to hear some research about the eco footprint of various joint compounds that addresses which is most sustainable in terms of manufacture, serviceability, durability?
USG: "Most USG building products have low negative impacts on the environment, including equivalent greenhouse gas potential, primary energy, and virtual water, among others.
However, this is not good enough. At USG, we are always innovating and redeveloping products to reduce their impact on the environment while improving overall performance of a build. Many of our products use gypsum as a base. Gypsum is the only material that can be heated, thereby driving off water and causing a solid-to-solid phase change, forming Plaster of Paris. When water is added, it gives off the same amount of heat turning it back into gypsum. Conversely, many other products use limestone and limes as their base.
Both these materials are defined by the USGS as a “perpetual resource,” or one that is virtually inexhaustible on a human time scale. USG also uses organic ingredients like starch as our binders and glue bases, as well as evaluates many secondary waste materials (both pre- and post-consumer recycled material) for substitution of virgin materials. For all USG products, we strongly believe in material transparency and claim verification, as needed.
Ready-mix type joint compounds, specifically, are no exception. USG Sheetrock Brand All Purpose Joint Compound (Green Lid) is the number one selling ready-mix joint compound in the industry. USG Sheetrock Brand ready-mix and drying-type compounds utilize a perpetual resource as the formulation foundation, as well as other ingredients such as organic latexes. We also evaluate the need for additives, such as mold inhibitors for improved shelf life, while striving to lead the way in assuring a sustainable and transparent product portfolio that meets the high demands of our customers.
We have tested our entire joint compound offering for their VOC emissions, TVOC, and VOC content (non-solid materials only), and continue to lead the way on a government mandated global compliance packaging change.
Green Builder: What progress has been made in the drywall mix over the past decade and is it any safer for workers. Could USG address some of the health concerns from this 1998 study, which says:
"A study by the National Institute for Occupational Safety and Health (NIOSH) has shown that "nuisance dust" from joint-compound mud used in drywall work can contain toxic materials. And, there can be dangerously high amounts of dust from sanding and other drywall work.
NIOSH conducted a Health Hazard Evaluation of dust and toxic exposures to 10 renovation workers at 2 sites doing drywall finishing. Measuring the air the workers were breathing, NIOSH found 9 of 10 total-dust samples at higher levels than limits set by the Occupational Safety and Health Administration (OSHA). More important, 2 of 13 samples of respirable (breathable) dust were above the limits OSHA says are safe. Two samples contained respirable silica. Silica can cause crippling and fatal lung diseases.
"The health effects associated with long-term chronic airborne exposure to the dust or particulates generated during drywall sanding are not known," the report said, adding that even when the dust amounts are within recommended limits, they may not be safe. This is especially true, the report said, when parts of the dusts are known to have a "biologic effect."
Besides silica, another material in the dusts that may be unsafe is kaolin. Found in clay, kaolin causes pneumoconiosis, or permanent lung damage.
What the documentation says: The Safety Data Sheet for USG's standard joint compound does not call out any especially serious risks although the material is classified as a "Hazardous Chemical" as defined by the OSHA Hazard Communication Standard, 29 CFR 1910.1200.
Our point in looking deeper at joint compound is not to create a scare around what has become an essential, important product in modern home construction. Rather, it's to point out that this product, like many building materials, needs to be treated with proper safety protocols. It's made to hold up for decades, to dry quickly, and remain stable. It's not meant to be applied, sanded, and inhaled eight hours a day without respirators and protective gear.
What we would like to see are more R&D efforts to steadily improve the composition of joint compound. It seems likely that safe substitutes could be found for silicates, and formaldehyde, at the very least. The company that does this first will have a great story to tell, and remove some of the risk associated with "maverick" contractors who are foolish enough to ignore the safety protocols when using this material.
US GYPSUM responded to the above article with the following letter, offered unedited, in its entirety--Editor
I’m writing to you in response to your February 10, 2016, article that features USG’s joint treatment products titled “How Green is Drywall Joint Compound? Looking Deeper into Materials and Health Risks.” We were disappointed that many of the important points that we shared with you on February 5, 2016, were not reflected in the article.
Editor: Many of these points were cosmetic in nature and not relevant to the building science information we were after, but I see in this letter you have been much more thorough in offering detailed building science answers. We're happy to reprint it here for readers looking to go deeper.
USG has been and continues to be a leader in joint treatment products and we have proactively addressed health and safety issues for these products for many decades.
For over 100 years, we have been the market leader, primarily because our formulators spend an enormous amount of time determining what our customers want, and then designing our products and formulas to meet those needs. As part of this leadership, we have addressed dust by (a) manufacturing wallboard panels in sizes that reduce the total length of joints to be treated; (b) by promoting low dust joint treatment formulas; and (c) by promoting formulations which in terms of their ease of use and functionality allow finishers to apply joint treatment using the least amount necessary, which in turn means less material to sand.
The industry uses many terms to describe these attributes, including, but not limited to: open time, feel, slip and trowelability. But in all cases, we are trying to find a product that goes on easily, doesn’t shrink and covers and conceals joints, fasteners and trims with the least amount of material necessary.
To appreciate all that has been done to mitigate health risks to drywall finishers, you need to look at not only our joint treatment products, but also at our wallboard on which the joint treatment is applied. Finishing wallboard joints takes time, and the labor cost for this task is far greater than the cost of the actual materials themselves. Drywall contractors don’t want to finish more joints than they have to, and for the joints that are necessary, they want to spend as little time as possible on finishing.
In other words, manufacturers, drywall contractors, health and safety professionals and the finishers themselves all share the same goal: to reduce time spent finishing joints, thereby reducing their exposure to any resulting dust from the finishing process. Over the decades, as a manufacturer of gypsum panels, we have helped achieve that goal:
- We designed the taper profile and the edges of our wallboard panels to accept only the amount of joint treatment needed to do the job.
- We offer custom lengths of panels, when customers ask, since custom lengths reduce the number of extra joints involved when hanging odd end pieces and minimize the wallboard waste onthe jobsite.
- In the 1990s, we started producing 54″ wide board (in addition to the standard 48″) to accommodate customers who wanted to finish 9′ high walls with only two pieces of wallboard rather than three.
I’d also like to point out that we have recommended the job practice of wet sanding joint‐treated areas for many years and we would be happy to send you some of our literature on the topic. While we know that wet sanding is not a universal practice among the drywall finishing trades that use our products, it has important advantages in terms of significantly reducing and/or eliminating respirable dust from the sanding operation. For this reason, we continue to recommend it as we have for many years. We provide the following product safety recommendations to our customers on all of our products:
CAUTION: Dust from sanding may cause irritation to eyes, skin, nose, throat and upper respiratory tract. Use only in a well‐ventilated area, wear a NIOSH/MSHA‐approved respirator. Use a sander with vacuum attachment or wet‐sanding to reduce dust. Wear eye protection. If eye contact occurs, flush thoroughly with water for 15 minutes. If on skin: Wash with plenty of water. If swallowed or irritation persists, call physician. Keep containers closed when not in use. For more information call Product Safety: 800‐507‐ 8899 or see the SDS at usg.com
KEEP OUT OF REACH OF CHILDREN
One specific concern we have with the article related to this point is the photograph that was used, which showed a worker wearing safety glasses, yet no dust mask, and holding a power tool up against a wall. The heading under the photo reads: “Bad Idea: Representing contractor sanding joint compound without a mask is commonplace and encourages risky work practices. Power sanders like this capture about 80 to 90% of the dust they toss.”
Your readers may believe that it was USG who was “representing contractors sanding joint compound without a mask and/or other necessary and recommended Personal Protection Equipment (PPE).” However, this is not a USG‐provided photograph, nor have we ever used this image. Instead, we believe it is a photo whose rights are controlled by the Festool Company. See the product page for the Festool 571579 Planex Sander LHS 225 (https://www.festoolproducts.com).
Editor's Note: We are not required to obtain rights when commenting on a photograph in the context of a news article. Since this was a journalistic article making a critical observation about the photo and its presentation, not a promotional piece, use of the photograph was within our legal rights. You are correct, however, that this is NOT a USG photo, nor is this a practice recommended or condoned by USG. In fact, that's the point of the photo and caption, to show how not all contractors and third-party manufacturers represent drywall sanding safely.
Recently, in connection with revisions to our warning labels and Safety Data Sheets to comply with OSHA’s GHS regulation, we retained independent third‐party professionals to conduct both in‐field and controlled laboratory studies of our joint compounds in an effort to assess potential exposure to silica and total dust. In both the field and the lab study, there were no exceedences of the OHSA Permissible Exposure Limits for silica.
We asked the independent third‐party professionals of those studies (Carnow, Conibear & Associates on the field study and R.J. Lee on the lab study) to submit their findings in technical papers to peer reviewed journals for publication. Additionally, these recent studies showed excellent results when power sanders were used with a HEPA vacuum attachment.
You stated in your article, “Another material in the dust that may be unsafe is kaolin. Found in clay, kaolin causes pneumoconiosis or permanent lung damage.” I wanted to make a point of clarification that kaolin is not “found in clay.” Rather, it is the name of a certain kind of clay. Kaolin is the most common type of clay whose principal mineral constituent is “kaolinite”, hence the common name kaolin (also known as china clay, ball clay and fire clay). This type of clay is extensively used in the paint, ceramic, and piping industries. Editor: Good point. Thanks for that clarification.
I hope this helps clear up some of misconceptions you may have of USG, our joint treatment products, as well as what we have done as the market leader for more than 100 years as the leader in addressing the safety concerns of the professional finishers and DIYers that proudly purchase and use our products each and every day. I will personally follow‐up with you to ensure that you received this correspondence, to answer any outstanding questions you may have, and to offer our access to our subject matter experts for further discussion/opportunity to interview. In the meantime, I’ve included my contact information below.
Kenneth W. Wagner, Manager, Integrated Marketing United States Gypsum Company, Email: email@example.com
What is joint compound made from?
The ingredients of joint compound are:
- Limestone >35%
- Attapulgite <5%
- Talc <5%
- Mica <5%
All concentrations are in percent by weight unless the ingredient is a gas.
Is joint compound safe?
One compound ingredient, Attapulgite, is considered to be carcinogenic under certain conditions in animal testing. These same conditions should not occur in normal human use of the material.
Consider this information about other components from USG’s product sheet:
- Vinyl acetic monomer, formaldehyde and acetaldehyde: Trace amounts of vinyl acetate monomer and formaldehyde may be found in this product.
- Attapulgite: Carcinogenic to experimental animals via a route of exposure not relevant to human exposure.
- Skin Sensitization Potential: This product contains an amount of Triazinetriethanol (THT) (CAS No. 4719-04-4) that is below the approved EPA regulated limits. THT can act as a sensitizer. Numerous human studies with concentrations up to 1% yielded negative (no sensitization) results. However, some results showed positive reactions in concentrations <0.5% mostly in persons with eczema.
- Crystalline silica: Raw materials in this product may contain respirable crystalline silica. Exposures to respirable crystalline silica are not expected during the normal use of this product. However, actual levels must be determined by workplace hygiene testing. Prolonged and repeated exposure to airborne free respirable crystalline silica can result in lung disease (i.e., silicosis) and/or lung cancer.
This article was originally published January 22, 2016. It has been updated and republished with new information to reflect changes in the technology and products.