Monday, February 14, 2011

Why TPE Yoga Mats are Not an Eco-Choice: A Review

The fabulous Babs from Babsbabble contacted me a week ago with the wonderful news that she had received a yoga mat to review from Kulae. We thought it would be fun to do a double review- her yoga use review and my "eco" review. Go on over and check out her 'yoga review'!

Nowadays, choosing a yoga mat is pretty darn complicated. Once it was pointed out that practicing on a yoga mat that was damaging our planet and our health with every breath and every asana... well lets just say the yoga industry jumped on the green bandwagon. Which is great... except for Mr. Greenwashing in the passenger seat.

Kulae mats are labeled as "ECOmat"s and their mission statement is:
At kulae, we are on a twofold mission to provide the most stylish + eco-friendly yoga gear on the planet while truly living by our mantra "karma's real".
so it would appear that they are serious about the whole protecting the planet thing. Unfortunately, words and claims in the eco-world aren't enough...

A "tpECOmat" is made from TPE (thermoplastic elastomers) and as a result is PVC and latex free. Delve a bit further and they elaborate with a
"TPE is a resilient, highly elastic material that is composed primarily of styrene-butadiene-styrene block copolymers" 
which of course clarifies what exactly TPE is made of for the regular yogi(ni) (ahem). Kulae state that the mats are: 100% biodegradable, 100% recyclable.

Lets take another look at what exactly is TPE (or thermoplastic elastomer): As I wrote in a previous post, TPE can mean pretty much anything from a type of plastic (ahem- thermoPLASTIC elastomer) to carbon to rubber (wiki). It's a ridiculously vague and lame term. One positive for Kulae, they're upfront about what type of polymers and copolymers make up their TPE: Styrene-butadiene-styrene block copolymers or SBS.... (um did your eyes just cross? cuz wow).

Now, trying to figure out what exactly SBS *is*... was almost impossible since I am not a chemist. Also, lay person google searches really turn up empty handed. Although not ideal, if we break up the chemical polymers we can get a better idea:

Styrene: Although named from the resin of the "styrax" tree, it is produced in industrial quantities from ethylbenzene... which is also usually created using chemical type properties (ugh chemistry). Styrene has also been described as a possible carcinogen by the US EPA (wiki).

Butadiene: is carbon and hydrogen and is produced in the USA by steam cracking which is a process that uses hugely high temperatures (often 900C) re: energy intensive. We also start to see "possible carcinogen" and health effects here (wiki).

Why do I care about SBS? Because if this stuff is actually going to "biodegrade" I want to know into what.

"Biodegradable" may appear like a nice pretty term, but in reality this term is not regulated at all and means virtually nothing in the "eco" world. Does it take 5 days or 20 years to break down? Can it break down in a airless, plastic wrapped bag in the landfill or in a compost bin? Or, does it need a high specialized, heat-processed municipal composting facility? What exactly will it break down into? DDT biodegrades into two compounds that are more toxic than DDT itself (Ecoholic Home 2009).

What about the pretty pretty mat colours? Do you think that the blue colour is a natural additive? Those colours are mostly like chemical dyes... and you can be sure they won't magically evaporate when they "biodegrade".

I did email Kulae over a week ago asking for specifics on the what, when and hows (and dye question) with no response to date.

Ok... so basically we still don't know what SBS really is, it's effect on the environment or our health and what it will break down into, how long would that take and exactly how are we supposed to compost this mat. I'm pretty sure you can't just toss this mat in your backyard compost pile, I *know* my municipal composting facility won't accept it and I happen to know that stuff rarely breaks down in airless landfills. So for practical reasons, this mat isn't biodegradable at all.

Finally, according to wiki, Thermoplastic elastomers generally "creep" and demonstrate: "poor chemical and heat resistance, high compression set and low thermal stability. TPEs soften or melt at elevated temperature above which they lose their rubbery behaviour. TPEs show creep behaviour on extended use".  

The definition of "creep" is
"the tendency of a solid material to slowly move or deform permanently under the influence of stresses. It occurs as a result of long term exposure to high levels of stress that are below the yield strength of the material. Creep is more severe in materials that are subjected to heat for long periods, and near melting point. Creep always increases with temperature." (wiki)
I would classify regular use of a yoga mat for asana as stresses... and hot yoga, or practicing outside (sun) most certainly would qualify as increase in temperature.

Ok. So my final eco-review verdict? Yes, Kulae yoga mats (and any other TPE mat) are a step above PVC. I highly doubt they would last the lifetime of a yoga practice and thus would need to be replaced eventually. They aren't practically biodegradable in the greenest terms and some of the constituents have been created using high energy.

Are they "eco"? Um... until I have more information on research indicating that SBS would be safe for us and our planet I have to say No.

Thank you Babs for this fun opportunity! :)

article copyright of EcoYogini at


  1. Thanks, Lisa! I appreciate the help slogging through the bs! The mats are fun, though.

  2. It seems to me that no yoga mats can truly be green. If you want green, wouldn't a blanket be the closest possibility to a green mat?

  3. @Babs, you're very welcome :) It was a fun blog event!

    @Anon: actually, I would say that natural rubber mats (like those made by Jade and prAna) would be a better environmental choice. We know where the rubber comes from, we know that they will last the lifetime of the yoga practitioner and are created from substances natural to our planet. Now- if only they could guarantee natural dyes.
    another option would be a jute mat- which i hear is pretty good.
    but a blanket...not really a viable or popular option for most north american yogis. :)

    1. not completely green either.. as the rubber plants do destroy a lot of nature and you need chemicals to keep the rubber smooth in stead of degrading.. anddd i think producing rubber cost a lot of energy too(like producing this stuff above)??
      im into cotton, hemp and cork but still haven't found the perfect combi:)

  4. Eco:

    I'm back!

    So, which type of yoga mat do you recommend? Rubber? I'm currently most curious about the Jade mats.

    As for TPE, I dislike simply the way they feel. They don't hold steady under me during Sirsasana or any standing balance pose. It's hard to explain, but they sway a bit. Too spongy.

    Come visit!


  5. Hey Eco-Yogini!!! I agree with your analysis of TER yoga mats (same for PER mats). I contend (IMHO) that I’m making the most eco-sustainable yoga mat “on the planet.” Yogasana yoga mats are hand-made of 100% cotton. After 3 days on the loom – they are signed by the weaver. They will not deteriorate in direct sunlight (like rubber mats) and will last at least 15 years. After that time they become a nice runner in your home and never end up in a land fill. Though you might want to know:

    1. Thank you for this comment!! it finally solidified which mat I should get after lots of research in which ones are non toxic. I just purchased my yogasana mat in saffron color! It truly is the only kind of mat to get that ensures it is not toxic and will last a lifetime! Thank you!

    2. Could you please tell me the website address for saffron yoga mats ?

  6. thanks for this site. I have like many of you been researching to find the healthiest and eco friendly mat. i am leaning toward the jute based one by barefoot yoga... will see. I read something interesting about natural rubber mats... that repeated exposure to allergens (as is rubber?) can actually start to cause an allergic reaction... just something to think about... it definitely makes me wonder if I want to expose myself to that every day... maybe there really is no eco friendly solution that is also health friendly, in a perfect way.(and we must check the dyes too)... we ought to go practice on the sand or grass, I guess! thoughts welcome. mahalo.

  7. fyi, natural rubber is also an elastomer and a thermoplastic (ie. a thermoplasticelastomer, TPE). natural rubber (cispolyisoprene) MUST undergo vulcanization to be formed into anything useful. without it, you'd be doing yoga in a sticky mess of rubber. vulcanization involves heating the rubber to HIGH temperatures with LOTS of sulfur. Do you know where sulfur comes from? You guessed it, petroleum! Do you know how that's going to biodegrade? Now, you may have guessed already that I am a chemist, but my goal is simply to enlighten people about "eco" choices. Just because something is "natural" does not mean it's perfect. If you want to be truly eco-conscious, you shouldn't have a yoga mat. in fact, you probably shouldn't have any manufactured possessions. And I'm not saying I'm any better than you (I have a TPE mat), but just realize that the only civilization that was truly sustainable was the stone age. The #1 goal of any company is to make money, no matter how much they appear to care for the environment.
    Also, there are specific places in the US now that will accept ANY type of yoga mat for recycling. you just have to look.

    1. Hey! I would love to hear more from you about this! I'm working with a brand at the moment trying desperately to avoid any "greenwashing" while pushing for the most sustainable production of mats possible! Have you done any more research? It would be amazing if someone actually delved right into this and 'ranked' the different options - mainly TPE and Natural Rubber i guess - to figure out which is the better choice.

  8. @Anonymous- Chemist: and can you tell that I am not a chemist?
    I think that's the problem- since when does the typical consumer HAVE to be a chemist? It's frustrating.
    With regards to TPE- My offense is that TPE is made from synthetic 'elastomers' whereas many natural rubber mats (like Jade and prAna) are made from the sap of a rubber tree (sustainably harvested). Which they state- on their site.
    Yes- the vulcanization involves energy- however how much more energy would be involved if you had to replace your synthetic 'TPE' mat every two-three years? Natural rubber mats last much much longer- thus decreasing energy use over the long term life of your practice.

    Also- most 'TPE' mats just say they 'biodegrade' without any further support or explanation. A typical consumer will assume that this means- 'throw in your backyard or municipal compost' or even worse- in the landfill.

    Jade and prAna (and manduka) all have links and resources for disposing of your rubber mat. prAna even states that their mat is glued together using non-toxic glues.

    I think my point here is that I never assumed to be a chemist and I resent having to do so because companies aren't providing enough information for the typical consumer. ESPECIALLY; I'm tired of the 'TPE' yoga companies being vague about what exactly they are selling, how to dispose and the 'eco-bility' of their mats.

    Thanks for your input- although you could have written me personally with your concerns about my post and I would have gladly adjusted it.

  9. I'm sorry if I sounded snippy or anything, wasn't the intent! knowing the structure of both natural rubber and the polymers used in TPE, i think it's a safe assumption to say they they will biodegrade into the same thing (namely carbon and hydrogen). the BIG advantage here is over PVC, where nasty chlorines are present. However, you mention that the TPE mats never claim HOW they're going to biodegrade, but I also can't find a simple statement from any company (that I believe) about how, and how long, it will take for a rubber mat to biodegrade. And both mats are going to require air and sunlight, both essential to the biodegradation process. Yes, Jade and prAna offer the recycling/reusing option, so essentially the whole 'biodegradable' statement is greenwashing - making you feel better about your purchase, and Jade and prAna are just as bad as the rest of them in that respect. But i believe TPE mats offer the same recycling benefits as rubber mats, if given the chance, although the verdict seems to be that rubber mats outlast who really knows!

  10. Hello it's me again - the Anonymous who made the comment about someone saying natural rubber mats have their own issues wrt being allergens. and repeated exposure to that creates its own problems... if you have any thing to say, eco-yogini, LOVE your thoughts and if the Chemist is still hanging around, love YOUR thoughts too... i know there is no perfect solution, there is shadow in everything, but as a journalist I like to look at all sides, be as thorough "as possible" and I found this "con" about natural rubber mats very interesting. and aim to learn more! mahalo.

  11. I'll tell you why I can't use a Jade yoga mat. I'm allergic to latex. Yes, a rubber mat for me over a time of constant use makes me break into hives.

    Anonymous has it right.
    As for "biodegradable," or "natural" claims, those are marketing terms used to get people to buy them (and feel better about themselves). Better to suggest alternate uses for the mats once they cease to be useful for yoga. Such as cutting them up for use as car mats, putting them in the back of a trunk or a tub to prevent slippage, etc. etc.

  12. Just an update on the Kulae mat...after four months of hard use, it is dead and flakey. I would not recommend.

  13. Well researched. Thank you. My yoga studio wants to carry a line of truly eco-friendly mats. Do you have suggestions as to which materials are the most eco-friendly?



  14. @Mike- Thanks for stopping by! :)
    I would say currently my favourite choice of yoga mat that withstands regular use would be a rubber mat. Of course you'll get other options like 'jute' or 'organic cotton' (or none), but if I ran a studio and wanted to provide eco-mat options to my clients I'd go w rubber. (prAna has a lovely rubber revolution mat, or Jade Yoga also has some fabulous rubber mats).

    For those who are rubber sensitive- I think TPE would be the next step up.... as much as I hate to admit. :)

    Hope that helps!

  15. I'd say it would be the FIRST question I'd ask anyone buying a Jade mat. Do you have a latex allergy?
    Because while someone with a latex allergy can use a Jade mat for awhile, as Anon2 found, they'll end up with a very bad contact dermatitis or hives after prolonged exposure. Nothing is perfect.

  16. Came back to this blog after a while... just found this - KORQ yoga mats... expensive yet say last a lifetime as cork is a supposed green and excellent choice... i did read that they use TPE on their foam (please confirm for yourself) and thanks to this blog I am finding out more about their TPE.... onward, BN

  17. PS - just read that 50 percent of labor force making KORQ mats (local/NYC) are blind... might be another reason to support...

  18. Thanks for this post. I am looking at purchasing a few "eco-friendly" mats for a budding yoga club, and I LOVE my Jade mat, but it's so expensive that I was briefly intrigued by these TPE mats. But I am "jaded" enough to know not to trust the "eco-friendly, biodegradable" labels without some investigation. TPE sounds like good ole' plastic to me.

  19. Hello :) I know this is an old post and it was very helpful and informative. I was wondering if you had to recommend a yoga/exercise mat, do you think 10mm thickness is pushing it? Also, do you recommend the jade, prAna or manduka? It's so confusing to know which is the safest/best one! Thank you very much in advance!

  20. If you really need mat for yoga.
    Please use cotton or wool.

    Yoga tradition is way older than plastic.

  21. As much as one would hate to admit it, pretty much everything is not truly eco friendly. This goes for your handphone, laptops, tv, tennis racket etc.
    For a thing like a Yoga mat, it would be up to an individual to choose what they are most comfortable with. If a mat is made of TPE which does seem to be a better choice compared to PVC, then this is something much better.

  22. very helpful and informative post. Thanks for sharing.


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