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Looking for Spray Foam with Low Global Warming Potential

washxhouse | Posted in Green Products and Materials on

I have a few tasks that call for closed-cell foam (vertical interior surfaces and air sealing in attic, rim joist in basement) and my cursory research indicates that the blowing agents used in most spray foams has massive global warming potential.

I’m having a dickens of a time finding an insulation vendor that has an opinion on the product they’re spraying, much less who knows the blowing agent it uses or its environmental impact.

I considered going back up the chain to Honeywell or another mfr that makes ‘green’ blowing agents to try to find a list of spray products using those agents and then go to those mfrs for a list of contractors who buy them but it seems like a convoluted way to go about it …

Is there a ‘green contractor’ site I should be looking at or is war-dialing the Yelp insulation category really the best way to go about this? Seems like a market opportunity if such a list doesn’t exist, although maybe I’m a bit of an outlier in caring enough about this to shop based on it.

I’m in Southeastern Pennsylvania BTW.

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  1. GBA Editor
    Kiley Jacques | | #1

    Good for you for giving this thought and doing your research. You should definitely read this article, as it talks about Heatlock spray foam, which uses a new generation of blowing agent with a lower global warming potential: Demilec Spray Foam Named Year’s Best Green Building Product.

  2. Expert Member
    BILL WICHERS | | #2

    It's the HFO blown foams that are greenest, although I've heard about a water-blown foam, but I've never seen that myself.

    Any spray foam contractor should be able to provide you with the manufacturer's datasheet for the product they intend to install in their quote. From that datasheet, you should be able to find out the blowing agents used. If you want to know more about what's in the material, ask to see the MSDS (Materials Safety Data Sheets) for the product, which will describe most of the more volatile components of the foam. If you want any more detail than that, the datasheet will likely list a technical support contact at the manufacturer that should be able to get you any additional information you need.


  3. Expert Member
    Michael Maines | | #3

    Here's an article I wrote that includes information about HFO-blown foam:

  4. Patrick_OSullivan | | #4

    HFO blown foams are becoming quite common. As I understand it (some of this is covered in Michael Maines's linked article), though federal requirements for it didn't get enacted, some states have pushed legislation mandating HFO, which has created market pressure to move to it.

    All the spray foam contractors I considered (in New Jersey) were using Demilec HFO. Ultimately I used Eastern ( The crew I had did a nice job, and I clearly saw they were using Demilec HFO High Lift.

    They seem to do work in Bucks County, so maybe they cover your area.

    1. woobagoobaa | | #7

      Same here. I had a recent CCSF install using Demilec HFO high lift (Eastern MA). HFO options seem pretty common in our area.

  5. jkstew | | #5

    Ecomate claims to have a blowing agent for their polyurethane foams that has no HFCs, CFCs, and no HCFCs. It is non-VOC with zero GWP.

  6. washxhouse | | #6

    Thanks for the replies everybody. I reached out to Demilec to see if they can connect me with a contractor in my area who uses Heatlok HFO.

    Meanwhile I also found a contractor who uses Nexseal by SES
    ... I confirmed it's using Solstice blowing agent so the GWP box is ticked ... the thing I'm far less clear on are the environmental implications of the other ingredients as well as how this product compares to others vis a vis impact on indoor air quality, which concerns me as a good bit of my application is in the band joist of a (unfinished but) frequently-used basement.

    Any leads on how I can parse the 'other ingredients' part of the SDS / TDS to get a better understanding of the health effects and environmental impact of the rest of this sort of product?

    1. Expert Member
      Michael Maines | | #8

      Washxhouse, I answered a Q+A for the next Fine Homebuilding about this. I've had their lifecycle analyses for a while but hadn't gotten around to calculating the impact yet. I found that using their values for HFO and HFC-blown foam, the HFC-blown foam has 4.2 times greater carbon emissions. Said another way, the HFO foam is 24% as harmful as the HFC-blown foam. That's using their assumption of a 75-year life in a building, and assuming that 50% of the blowing agent remains encapsulated over that time frame. Almost all of the carbon emissions happen before or during installation, so it's a big carbon polluter either way. But if you have to use foam, HFO is still much better than HFC-blown.

      You can find the source documents here:

      1. washxhouse | | #9

        Thanks Michael - that's very helpful for understanding the role the blowing agent plays in the overall footprint of the application. A 4-fold improvement is nothing to sneeze at but it puts in perspective the ~1400:1 GWP numbers you see when strictly comparing HFC to HFO. There's still a lot of plastic involved :/

    2. washxhouse | | #10

      I should clarify re: the above that I'm hoping to gain some insight into how to compare 'apples to apples', meaning what are the environmental and indoor air quality implications of using X CCSF vs Y CCSF?

      Are there particular (standardized) metrics I should use as the top line? Are there red-flag ingredients?

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