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 ecoyogini.blogspot.com