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Q&A Spotlight

Is Tripolymer Spray Foam Insulation a Healthy Choice?

Phenol formaldehyde vs. urea formaldehyde: Confusion is king when two types of foam insulation bear the same name

Spray foam comes in many varieties. High density, low density, medium density, polyurethane, phenol formaldehyde, and urea formaldehyde. But is formaldehyde a safe ingredient?
Image Credit: Fine Homebuilding # 204

When builders talk about spray-foam insulation, we assume they’re referring to a two-part polyurethane compound. But not always, as a recent Q&A demonstrates.

Amanda Cordano launched an interesting but inconclusive conversation when she asked for advice on “Tripolymer product,” which had been told was a green product with no health risks.

Cordano found nothing to contradict that in her queries on the web, but she points out that all the sites she found were sponsored by foam companies. “Do you have any information on the potential downside of this foam?” she asks.

Which ‘tripolymer’ is it?

The first step might be to identify exactly what Cordano is asking about. “Tripolymer” is a product of C.P. Chemical Co. of White Plains, NY, marketed as Tripolymer 105. The company says it is composed of “modified phenolic based methylene bound copolymers” that were first developed by C.P. Chemical in 1966 as a fire resistant thermal and acoustic insulation.

According to C.P. Chemical, the foam won’t melt, and won’t support combustion. Its combustion byproducts are “significantly less toxic” than those of white pine.

Like polyurethane insulation, Tripolymer is a two-part compound. Unlike polyurethane foams, Tripolymer 105 does not expand as it’s applied. It solidifies within 30 seconds and has a density of between 0.8 lb. and 1.3 lb. per cubic foot. Cured Tripolymer has a perm rating of 15.5 to 16.9 per inch and R-5.1 per inch. The company says it shows no thermal degradation over time.

Here’s where the confusion sets in.

Cassie responds that tripolymer is urea-formaldehyde insulation. “It is plastic. Will not burn, but it will melt and the fumes will kill you. Recently marketed in Canada under the name Retro foam. Once the Canadian government found out, the company was shut down and is now in a 500…

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  1. Skylar Swinford | | #1

    Tripolymer vs Thermco
    How does the Tripolymer foam differ from Thermco's pour in place foams? The products look identical to me. A local installer is advertising the Thermco foam as a healthy "petrochemical free" foam. Naturally they make no mention of formaldehyde in their marketing. I spoke with the installer and he stated that the foam is "nitrogen" based and only has trace amounts of formaldehyde. I decided to give Thermco a ring and spoke to their VP. He was helpful and willing to answer any questions. Unlike C.P. Chemical, Thermco acknowledged that their product is a urea-formaldehyde foam.

    Thermco supplied me with an MSDS sheet for the foam, which calls the product an "Amino Plast Foam" that "does not burn" and states "the smoke is made up of carbon dioxide, water carbon monoxide and Amines. No toxic vapors come forth"

    The resin MSDS sheet states that the foam contains "Polymethylene Urea Resin".

    The "Thermco Foaming Agent" contains: "1) Alkalisalt of Alkylnaphthalene. 2) Phosphoric Acid (Orthophosphoric Acid). 3) RESOURCINOL (1,3 dihydroxybenzene)."

    It might be worthwhile to note that the supplied MSDS sheets were from the years 1989-1994.

    Thermco also provided an off gassing report. The test was performed in accordance to ASTM C-951 to test for "free aldehyde" content. The results were marked "Not detected, less than 0.06%".

    As it stands, I am going to stick with the tried-and-true stabilized borate cellulose in existing wall cavities.

    Scott, I enjoyed your article and I am happy to learn more about this product. However, I think the use of "spray" in the title is a bit confusing. The photo of the technician spraying polyurethane foam below the title further serves to mislead readers. My understanding is that this product is a "pour/injection foam" rather than a "spray foam".

  2. John Cunningham | | #2

    Friability in Cementous Foams
    Thank you for the basic analysis of issues around Tripolymer and Retrofoam. I am somewhat concerned about the urea formulation, but I believe that the larger issue with this product is its physical characteristics when installed.

    We are a spray foam contractor in SE Michigan and have been looking at cementous foams for several years. I started the company in 2005 largely because of the discomfort that I felt in a drafty old house. It was difficult to find information about insulation alternatives and contractors that I could trust to do the work. Since that time we have specialized in using expanding polyurethane foams in new build, retrofit, and wall fill applications.

    All foam installations are installer specific - the quality of the final result rests largely with the company installing the material rather than the material supplier. In the case of polyurethane foams the quality of the installed product is based largely on how well the technician manages the variability in the installation environment: the temperature of the material, the substrate, the ambient temperature; the moisture content in the substrate and relative humidity in the air, among other variables.

    We are not installers of cementous foams at this time, but we understand that the main issues with the application of these products involves the mixture of the component parts, and management the water content of the cavity and the material. Since the material is water based and sets while drying, the quality of the product relies on the speed that it dries in the cavity. If it is too wet, it can ooze out through gaps in the wall assembly. If it is too dry, it will dry too quickly and shrink excessively. We understand that shrinkage of 5-10% is the spec for this product. We have been involved in removal projects where we saw 1" or more gaps in tripolymer.

    In addition to shrinkage - we are concerned with the structural integrity of the project. The material looks and feels like chalk when it sets, and crumbles easily in your hand. It evaporates when exposed to water.

    The great advantage of cementous foams is exactly that they are not expansive; they are mixed in the truck and can be pushed up to 20 feet into a wall cavity - they say. The process is very similar to a standard cellulose wall fill project - except that you have a greater ability to push around obstructions and you at least are not dealing with a fibrous product. The disadvantage of a polyurethane wall fill job is that the material is expansive: it can not travel more than 3 to 4' in a wall cavity, and can sometimes crack or bow the wall. At the same time, once polyurethane is in, it is structurally stable.

    I am not a chemist, but I doubt that urea can be completely removed from retrofoam/tripolymer product. Hopefully the urea content and its impact on indoor air quality can be accurately and fairly characterized, relative to all of the other household products that contain urea. There are alternatives, like airkrete that you did not cover in this article, but this product has similar physical characteristics to other cementous foams. We love the idea of filling walls safely, effectively, and economically. Our customers are asking for this service. We look forward to innovations in product and process that will make this very needed application accessible to more home and building owners.

    John Cunningham
    Arbor Insulation

  3. Jim Baerg | | #3

    Cavity foam options
    Thanks for introducing this subject. I live in a 1914 brick house that has 2 wyths of brick separated by a 2.5" air space in the exterior walls. I've been looking for a insulation product to fill the gap and have considered loose fill pour (perlite & styrofoam beads), UA foam and cementious foam. The latter two options can be installed by drilling 5/8" holes in the mortar joints on appx 4'o.c. which is a very attractive solution.

    I've done a tweb based search on the history and use of UA foams. UA is allowed in commercial projects (primarily in CMU walls of big box stores) in the US, and continues to be used in Canada and Europe. The horror stories from the 70's were largely caused by application errors and seem to be largely remedied. The studies that I was able to find (esp Canadian) point to extremely low levels of ambient formaldehyde after curing. I was also struck by the lack of hard science on the health effects of formaldehyde.

    That said, I am hesitant, and have turned to the cementious foam products. Unfortunately, there are no applicators in the area.

    Any suggestions?

  4. Steven | | #4

    Tripolymer foam
    being in both plastics and construction depending on work situation I would like to clarify some things. when talking about foam, or to produce foam you have a chemical reaction, especially anytime you have a part A and B whcih must be mixed. If not properly mixed you can have issues, basically you do not get a cure that is necessary, maybe excesive outgassing and than as the gentleman stated temperature on the day of installation plays an important role.
    When someone state a tri -polymer, they are talking 3 componet, ABS plastic is a terpolymer consisting of 3 polymers.
    If someone states that a foam does not melt, it can be correct, if in fact the resulting mix was such as to create a thermosetting polymer. does this mean it does not drip when flaming no... but in most cases a thermosetting polymer with a flame retardent well just charr.
    IF the resulting foam is a thermoplastic it well soften and can melt if of the proper family.

    I hope this helps those of non technical nature.

  5. Phil in MN | | #5

    Shrinkage is a major issue with this product. Exposure to heat and humidity leads to dimensional shrinkage and general deterioration allowing gross air movement around the material diminishing any remaining effectiveness.
    Historically Installation / operator error was a major wild card in installation which meant that it is unpredictable if or not there would be a problem.

    My experience as a contractor in the late 70's early 80's was "This stuff is crap!" Tripolymer / CP chemical was playing the same game then as the magic of chemistry nomenclature permits as much camouflage and a manufacturer needs........

  6. Torsten Hansen | | #6

    spray vs. pump foam
    My company installs both polyurethane foam and cementitious foam. Polyurethane foam expands after application - cementitious foam does not. Polyurethane is generally spray applied, cementitious foam is pumped. (Some polyurethane manufactures offer so-called pour foam which is processed on standard spray equipment but can be injected into a closed cavity. That process is tricky to control because the foam expands after it leaves the gun).

    We have found that polyurethane spray foam is the better choice for any kind of open cavity work while cementitious foam shines when it comes to existing wall cavities.

    The decision to go with a cement based wall foam was based on an evaluation of the alternatives. In our market (Cleveland, OH), Tripolymer and Retro are both well represented and have a long history of shrinkage. When opening walls insulated with these products, we have found that there can be significant gaps between the foam and all six sides of the wall cavity.

    I like that cementitious foam - we use Air Krete - has no outgassing whatsoever and that it is inherently non-combustible.

    Air Krete does not shrink. When we started with this product years ago, we built a test wall with plexiglass on one side to practice our pumping skills. When we were done experimenting, we let the wall sit filled with Air Krete. Much banging on it and moving it about has followed and the material is amazingly stable - and again, no shrinkage.

    We have used Air Krete with pretty much any kind of wall - brick on frame, brick on brick, block, regular frame - and have had few problems. So Jim, if you can find an installer, Air Krete is recommended for your application.

    As John points out in his post above, it is all in the hands of the installer and while the Air Krete material itself does not expand after it leaves the gun, the pumping pressure can be enough to blow a wall.

  7. Harvey Goolsby | | #7

    blind cavity foam insulation
    1. Years ago, when I fiirst encountered the polymer foam insulations, there seemed to be a problem with shrinkage (even for the short distance between studs) and it was not recommened for attic insulation. Is this still so?
    A situation regularly encountered is the need to add insulation to cathederal ceilings, in the depth-of-rafter space, above R-ll or R-16 batts. Tri-poplymers dont expand, but this is a roof situation.
    Is anything new or is help available?

    2. The cemetious foams are interesting, but drying rel;eases a lot of water. This sets up limited uses. What is the chemical or process difference in the end product between these foams and the AAC (Autoclaved, aerated concrete being shipped from Florida and soutyh Georgia?

  8. Dave R. in Ohio | | #8

    Stability of PU Foam
    Are PU foam formulations used in cavity fill insulation stable over time? I recall many PU foam products that turn to sticky "goo" after a few years due to hydrolyzation of the PU. Do the in situ (mix- react-cure-in-place PU formulations used in home insulation contain stabilizers to prevent such hydrolysis which causes the polyurethane to break down over time? My recollection from college chemistry is that polyether polyurethanes are much more stable than polyester polyurethane which are more common because they are less expensive.

  9. Bob Sullivan | | #9

    Amino-Plast Foam
    Five US amino-plast (a/k/a urea-formaldehyde) foam insulation manufacturers are active to include: CfiFOAM, Inc., Knoxville, TN; Polymaster, Inc., Knoxville, TN; C.P. Chemical Company, White Plains, NY; Thermal Corp. of America, Inc., Mt. Pleasant, IA and Tailored Chemical Products, Inc., Hickory, NC. Five states (NJ, MA, CT, NH and CA ban amino-plast

    Products offered by CfiFOAM, Inc. and Polymaster, Inc. combine a "dry-powder" resin component with a liquid foaming catalyst to generate foam which, in turn, is injected to fill wall cavities. CfiFOAM's liquid foaming agent does not contain resorcinol; thus, "brown staining" is avoided.

    All five manufacturers promote injection foam for insulating masonry wall assemblies. Most often to insulated single wythe concrete masonry walls found in commercial and institutional buildings. In areas where residential builders frequently build with concrete masonry, injection foam is often selected.

    Some manufacturers market what may be called ultra-low VOC (formaldehyde) foams suitable for new and existing framed walls. InsulSmart, offered by CfiFOAM, is an ultra-low VOC foam that has achieved the threshold required for Greenguard IAQ certification a few weeks following installation. Work is ongoing to shorten the timeframe so that certification may be possible.

    Health Canada and Massachusetts' Department of Public Health both actively enforce their respective ban of amino-plast insulation foam. Even though C.P. Chemical states that "Tripolymer 105" not amino-plast foam insulation, like Polymaster's "Retrofoam," Health Canada and the Massachusetts both ban "Tripolymer 105."

    For the most part, amino-plast foams offered today do not present the same problems that often plagued UFFI in the 70s and early 80s due largely to poor installation practices. Years of success with masonry applications have encouraged CfiFOAM to develop advanced technology injection foams geared to finally overcoming the remaining vestiges of stigma that burden our industry segment. Recent promising advances may enable CfiFOAM to soon approach zero formaldehyde emissions while very nearly eliminating shrinkage.

    Bob Sullivan
    Technical Services
    cfiFOAM, Inc.
    P. O. Box 10939
    Knoxville, TN 37393
    Email: [email protected]

  10. Anon | | #10

    UFFI foam shrinkage
    A recent investigation of a New Zealand UFFI product called Airfoam has shown that because of shrinkage the insulation performance is about half what the manufacturer was claiming. See BRANZ Study Report SR233

  11. jonathan | | #11

    Polymer solubility
    Laboratory synthetic methods are generally divided into two categories, step-growth polymerization and chain-growth polymerization[5]. The essential

    difference between the two is that in chain growth polymerization, monomers are added to the chain one at a time only[6], whereas in step-growth

    polymerization chains of monomers may combine with one another directly

  12. jonathan | | #12

    Contract analytical services
    HPLC typically utilizes different types of stationary phase (hydrophobic) saturated
    Polymer solubilitychains, a pump that moves the mobile phase(s) and analyte through the column, and a detector that provides a characteristic retention time for the analyte. The detector may also provide other characteristic information.

  13. Bob Sullivan | | #13

    New Zealand
    Readers of BRANZ' report might also consider reports of a BRANZ' board member having equity in a fiberglass manufacturer. Report's authors concede that "serious errors are relatively rare."
    Pitting one kind of insulation against another kind of insulation is a strategy too often employed.. I like what Joe Lstiburek said: "All insulation is good. More insulation is better."

    Hopefully BRANZ will continue their work until these serious but "relatively rare" deficiencies are overcome. In over 40 years around the US insulation industry, I've seen every type of insulation installed deficiently. Batts cut too short or too narrow. Batts missing. Batts installed backward. Cellulose and overblown fiberglass loose-fill settled or missing. SPF applied too thinly or not correctly proportioned.

    Finding fault is easy. Manufacturers and installers who overcome challenges are the ones who best serve consumer interests. Hold judgment until final results are known.

  14. Anon | | #14

    Bob, looks like Airfoam agrees with BRANZ as they have taken the RSI 2.9 claim off their website.
    Since you pretend to know about the investment holdings of BRANZ board members perhaps you can tell us about the insulation properties of AIrfoam and Retrofoam. Facts not fiction please

  15. Frank | | #15

    UFFI foam thermal resistance
    It doesn't matter if its healthy or not if its only R2.4 per inch!

  16. Anonymous | | #16

    Airfoam New Zealand
    'Pitting one kind of insulation against another kind of insulation is a strategy too often employed...'
    I believe everything you say My Sullivan.

  17. Bill | | #17

    I have noticed the only
    I have noticed the only people that say tripolymer is not a phenol-urea-formaldehyde resin are the people selling the stuff. The owner of C.P. chemical filed a patent in 1980 number 4345061, You can look it up on Sure sounds like the insulation is a formaldehyde resin.

  18. Anonymous | | #18

    Knowledge is the key
    I understand everyones worries and concerns. But in looking at formaldahyde you have to understand that it is everywhere in our lives and it is safe. We actually offgass it ourselves everyday about 1.5 ounces. People want to beat up these companies and yes I have an insulation company that installs Thermco's foam.
    Here is a few different things to think on we have formaldahyde in most toothpastes that we use, Fiberglass insulation has it in it, OSB uses it, yes and most pairs of your underwear that you have on uses it.
    Nothing wrong with making sure we are safe and healthy but people should do there own reading and investigations because lots of things that are said are false.
    The original case was dismissed in the supreme court because the rats that were getting cancer were exposed to 600 times the normal amount we usualy see.
    The unvented propane fireplace in your home gives off formadahyde as does cigarette smoke,carpets,kitchen cabinets, furniture, and yes lots of nail polishes.
    I may not be able to type everything properly but I have read as much as possible to make sure I am informed as much as possible. Maybe our law makers should do the same!!

  19. bill | | #19

    Laws are laws and until they
    Laws are laws and until they are changed pumping a plastic formaldehyde foam is against the law in certain states like Connecticut and Massachusetts. Sell it in states where it is legal or get the LAWS changed.

  20. Frank | | #20

    UFFI foam shrinkage
    It's illegal in ALL states to mislead customers about the insulation performance
    The R-value Rule comes to mind - If it shrinks or settles the R-value must be adjusted accordingly

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