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XPS Makers Announce More Planet-Friendly Formulations

Owens Corning moves completely away from hydrofluorocarbon blowing agents in its revamped insulation

Still pink, but climate friendlier. Owens Corning is changing its formulation for Foamular extruded polystyrene insulation to eliminate a blowing agent with a high global warming potential. Photo courtesy Owens Corning.

Two of the three manufacturers that sell extruded polystyrene insulation in the U.S. have announced changes in product chemistry that will reduce the insulation’s contribution to global warming.

Owens Corning and DuPont both said the blowing agents used to make XPS insulation will have lower a global warming potential (GWP) beginning early in 2021. The announcement from Owens Corning appears to be the more significant of the two, with the company saying it will completely eliminate a hydrofluorocarbon called HFC-134a and replace it with newer chemistry that has a GWP 90% lower than its current blend. Its new board is called Foamular NGX (for Next Generation Extruded).

DuPont also is promoting a revamped XPS made with a lower GWP blowing agent. But the company declined to answer questions about the new formula or what its GWP might be.

The announcements are the latest developments in a long-running legal and regulatory battle aimed at reducing the environmental damage from refrigerants used by a variety of industries, including XPS manufacturers. Beginning with the Montreal Protocol in 1987, efforts were at first intended to remove chemicals that destroyed atmospheric ozone. Now, the push is to find refrigerants that neither destroy ozone nor trap heat in the atmosphere.

For XPS producers, the challenge has been to remove HFC-134a—a widely used hydrofluorocarbon with a 100-year global warming potential roughly 1,400 times that of carbon dioxide—while still meeting various performance and manufacturing requirements. Government efforts to phase out HFC-134a in the production of XPS date back to 2015 when the U.S. Environmental Protection Agency announced a new rule that would eliminate the chemical as a blowing agent in XPS by January 1, 2021. Canada approved a similar rule.

But SNAP Rule 20, as it was called, was successfully challenged in court, with much of the rule vacated by a federal district court in 2017. The U.S. Supreme Court declined to review the decision. Then, in mid-2020, the EPA proposed SNAP Rule 23, which allowed the continued use of HFC-134a in XPS as long as it was in combination with certain other refrigerants. The rule has not been finalized, so it has not taken effect.

Owens Corning said at the time that it was prepared to meet the 2021 deadline for eliminating HFC-134a, and the company has now followed through with a hydrofluoroolefin (HFO) blowing agent. It has a GWP of less than 80, according to Frank O’Brien-Bernini, the company’s vice president and chief sustainability officer.

“Yes,” O’Brien-Bernini said in an email, “134a has been completely removed.”

Foamular NGX will use a proprietary blend called Opteon 1100, which is manufactured by Chemours. HFOs were originally developed by Honeywell for use in spray polyurethane foam insulation, but XPS manufacturers until now haven’t been able to adapt the chemical for use in their products.

The transition away from HFC-134a is likely to please green builders who have objected to the use of XPS because of the current blowing agents. They have preferred expanded polystyrene (EPS), even though it has a lower R-value per inch, because the pentane used as a blowing agent has a GWP of about 7.

O’Brien-Bernini said Foamular NGX would be available in Canada and in states with a Jan. 1 compliance date for the removal of HFC-134a—a list that includes California, Colorado, New York, Vermont, Washington State and possibly New Jersey—early next year.

“We are not limiting the availability of NGX. Our intent is to make NGX available throughout North American to any customer that wants to purchase NGX,” he said. “NGX has virtually all of the same performance attributes as our current Foamular product line, and can be used in all of the applications into which we currently offer Foamular.”

The R-value of 5 per inch is unchanged, but the NGX is likely to cost more than its predecessor. O’Brien-Bernini wasn’t specific, saying only that the price will be “set by the market.” HFO blowing agents cost significantly more than the HFCs the industry has been using.

A confusing legal landscape

The regulatory backdrop for the changes is complicated, and still in flux. Paul Lewandowski, the director of regulatory law at Owens Corning, said in a telephone call that in 2018, following the effective repeal of SNAP Rule 20 for insulation manufacturers, the company focused on changes for the Canadian market where the 2021 prohibition against HFC-134a remained on the books. Owens Corning assumed it would continue using its old blowing agent in the U.S. until Congress stepped in and clarified the situation here.

But individual states intervened, deciding they weren’t going to wait for Congress to act. Some of them passed their own bans on HFC-134a that would kick in at the start of 2021. They generally including sell-through provisions that would allow manufacturers to unload stock they had already made with HFC-134a.

In another legal wrinkle, some states adopted what Lewandowski called conforming language that required them to permit the use of a blowing agent that the EPA had approved. If SNAP Rule 23 is finalized by the EPA, DuPont can continue to sell XPS with an HFC-134a blowing agent beyond Jan. 1.

If the rule is not finalized?

“DuPont is going to find itself in a tough situation in about three weeks, I think,” Lewandowski said. “Although there is sell-through language, so they may have loaded the market in those states that have regulated HFC-134a. If they’ve loaded the market with eight or 10 months of product, they may have time to find a solution, test that solution and convert. We don’t know, but we’re ready, so it doesn’t’ matter to us except from a cost standpoint.

“Right now,” he continued, “as of the first of the year, product that’s made after 1/1/2021 cannot be made with a blowing agent containing HFC-134a if you’re going to sell that product in Washington, California, Colorado, New York, Vermont or New Jersey.”

Styrofoam gets a new color

DuPont’s situation is not as clear. The company launched a  website called Beyond Blue to promote the new XPS. It emphasizes its new “design friendly” grey color (the old Styrofoam is blue) and says the revamped insulation will have a reduced GWP. But the company declined to answer questions about what blowing agent it would use—whether it was based on one of the HFC-134a blends, or made use of an HFO.

“DuPont considers the exact formulation changes itself to be proprietary,” a company spokeswoman said. “An EPD [Environmental Product Declaration] will be published that serves as an independently verified, transparent communication of the product’s life-cycle environmental impact.”

The reduced GWP Styrofoam will be rolled out next month in Canada and 10 U.S. states. It will have the same R-value (R-5 per inch). DuPont said pricing would be competitive but wasn’t specific.

DuPont was behind proposed rules that loosened the phaseout of HFC-134a in SNAP Rule 23, arguing that despite years of research it had not been able to come up with a suitable replacement for the chemical. How the company views the legal quagmire that Lewandowski described is unknown.

Kingspan, a company headquartered in Ireland, also makes XPS for the U.S. market. Its U.S. headquarters is located in DeLand, Florida. The company did not respond to requests for information.

The trade association representing XPS manufacturers, the Extruded Polystyrene Foam Association, didn’t offer any additional information. Drew Brackbill, manager for legislative and regulatory affairs, said in an email, “We can’t comment on the topic of HFC-134a at present.”

-Scott Gibson is a contributing writer at Green Building Advisor and Fine Homebuilding magazine.


  1. Jon_R | | #1

    Just so nobody skims the hype and gets the wrong idea - don't use any XPS that isn't labeled Foamular NGX - which probably won't be available in your state. And EPS will still be better for the environment and less expensive per long-term R.

  2. charlie_sullivan | | #2

    Thanks for digging into that! It's disappointing that only Owens-Corning was forthcoming with any information.

    I'm pretty sure that new Dow product is essentially the equivalent of Neopor or other graphite-doped EPS (sometimes called GPS), but made with extrusion instead of expanding beads in a mold. They mention that it is gray because of a carbon black additive, and they give guidance on ensuring adequate ventilation in storage and transport to avoid flammable gas buildup, which sounds like the blowing agent is a hydrocarbon, as with EPS. That flammable gas issue might persist a little longer with XPS than with EPS because it comes out more slowly, so it might require attention to that aspect for a longer time period.

    Ultimately, the carbon black might mean that the Dow product retains its R-value longer than the Owens-Corning product.

    As much as I'm pleased that Owens-Corning is making that available, I'm not sure there are many situations when it would be the material of choice. Regular EPS is cheaper per unit R-value, and GPS is likely cheaper than NGX and retains its R-value better for application where you need 5/inch rather than 4/inch. The biggest advantage over EPS might just be availability at Home Depot. It will be interesting to see whether Home Depot stocks NGX outside of the states with regulations and makes it available by special order.

  3. BCinVT | | #3

    The new federal spending/ Covid relief/ climate spending bill announced yesterday is fazing out all HFC use over the next 15 years or so. it seems mostly a matter of replacing the use in refrigeration, but presumably it would also apply to other industrial uses. Unbelievably, some Republicans were in favor, having been lobbied by the chemical industry , looking forward with replacement materials.

    This is part of a global effort to ban the chemicals because of the greenhouse gas numbers.

  4. dwhittington | | #4

    It would be nice to know when XPS and Spray foam hit a tipping point where the embodied carbon/GWP issues become acceptable. For years, you've been publishing articles about how foam potentially has to long a payback period, but do products like Formular NGX or FOAM-LOK 2000-4G change that equation?
    When would they get to a point where we can expect a Pretty Good House 3.0 that maybe reincludes Foam above grade?

    1. Expert Member
      Michael Maines | | #6

      If there is an alternative material available that has similar R value and cost but lower carbon emissions, the higher-emission material will never recover its carbon debt. With US-made wood fiber insulation about to hit the market at a competitive price, I don't think there will ever be a PGH iteration that promotes foam above grade on new construction.

  5. clayisland | | #5

    I recently used the dupont grey foam, when I get up close it has an odor, I don't remember this with the blue foam. I would love to find or home brew a non toxic foam.

    I am cynical of all things government and big business. I trust there is money behind any legislation. I am wondering who benefits? Did Owens corning support this law because they figured out an alternate chemical, or did the chemical makers want to eliminate competition??

    I am 100% certain the industrial complexes don't give a flying fig about us, somehow someway this is sticking it to regular people.

    The store that sells the foam told me CA also banned gas generators, we can only buy the expensive big battery ones. Having used both, the electric is clean and quiet but also horribly unreliable and becomes an expensive brick paper weight very easily, and shipping companies don't want to ship them back for repairs. What a clusterf.

    1. Expert Member
      Michael Maines | | #7

      The alternative chemical is hydrofluroolefin, the same refrigerant/blowing agent used in HFO-blown closed cell foam. I share your distrust of big business but there is a lot of consumer demand for lower-impact products.

  6. VS71106 | | #8

    I certainly have liked the lower GWP of refrigerants/blowing agents of the HFO chemistry, but I am concerned about trading a greenhouse gas (bad!) for a persistent organic pollutant PFCA (bad!).

    I'm not wise enough to be able to tell the difference between the blowing agent Opteon 1100 (Also known as "HFO-1336mzz-Z or Cis-1,1,1,4,4,4-Hexafluoro-2-butene") and Opteon YF ("HFO-1234yf," or "2,3,3,3-Tetrafluoropropene") but when I see both contain Fluorine and the Opteon YF one breaks down into a persistent PFCA/PFAS, I wonder if we aren't trading one bad air pollutant for one bad water pollutant?

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