Do you practice yoga or Pilates? Both practices have become a vital part of my health maintenance routine. If I skip a few days, my body lets me know right away. So, since I must exercise regularly, I need a good, and, most importantly, safe yoga mat. Unfortunately, if you are not careful you may expose yourself to potentially toxic chemicals in your exercise mat. Obviously, inhaling and skin absorption are the two major routes for letting potentially harmful chemicals into your body. Lately, PVC yoga mats have been in the limelight because of their alleged toxicity. But are they really that bad? Join me in my research to draw your own conclusion about the safety of your polyvinyl chloride yoga mat.
It is crucial to use credible sources in evaluating PVC yoga mats.
For starters, I have been in the product safety research business since 2012. Both my MBA degree and financial analyst experience have been of great help in the field of research. Nowadays, due to my expertise in this area, manufacturers and online retailers hire me as their product research and development consultant. I was also in a documentary that you can learn more about on my About Us page.
Using credible sources is crucial in evaluating product information, so I do not rely on marketing claims. Instead, I read Cosmetic Ingredient Reports and PubMed publications. Additionally, I go to the European Chemicals Agency and the Scientific Committees on Consumer Safety databases, to name a few. The EWG is a useful tool, too, but you must learn to use the Skin Deep Database the right way.
Several years ago, when I did my first research on PVC yoga mats, I concluded that I should avoid PVC products. I was definitely glad that I did not own a polyvinyl chloride yoga mat. However, when I revisited the subject, I discovered articles by the chemical industry extolling the virtues of PVC. After reading them, it is easy to conclude that PVC is one of the best materials created by humankind. From every angle – environmental, production, safety, application – they described vinyl as an ideal material for every area of our lives. But to formulate my opinion about product safety, I look at independent sources to get a well-rounded view.
A polyvinyl chloride mat is not a non-toxic yoga mat.
To lay the foundation, let us look at the essence of PVC.
Polyvinyl chloride, commonly called PVC or vinyl, belongs to the group of chloropolymers. They produce chloropolymers from alkenes by replacing one or more hydrogen atoms with chlorine. Polyvinyl chloride is the third largest-selling commodity thermoplastic after polyethylene and polypropylene. Imagine that more than 40 million tons of PVC are produced worldwide every year (source).
Further, the raw materials for PVC come from salt and petroleum. First, they produce chlorine by electrolysis of saltwater. Then, they combine chlorine with ethylene obtained from petroleum to form vinyl chloride monomer (VCM). Next, they polymerize VCM molecules to form PVC resin. Finally, they compound PVC resin into PVC compound. During this process, they combine PVC with additives which determine the properties of the products, e.g., color, clarity, and flexibility.
All PVC materials use functional additives which include heat stabilizers and lubricants. Additionally, they use plasticizers to make your polyvinyl chloride yoga mat flexible (source). Potentially, PVC yoga mats have all these additives, so let us talk about them.
Heat stabilizers prevent PVC decomposition by heat.
To begin, stabilizers in plastics prevent environmental effects of heat or UV light and mechanical degradation during processing and use. The available heat stabilizers for PVC are organotin compounds, antimony, organochlorines, lead compounds, and cadmium (1).
First, the organotin compounds in PVC are mainly mono-butyltin (MBT), dibutyltin (DBT), and tributyltin (TBT). This study evaluates their toxic effects on in vitro human cells. All three had a negative impact on human cells. DBT and TBT revealed the most toxic effects even at low concentrations.
Second, antimony enhances the flame-retardant effect of chlorine in PVC. In 1990, the state of California added antimony oxide to the list of carcinogenic chemicals (source). This review provides an overview of what scientists know about the toxic effects of antimony. In sum, they attribute the numerous negative health effects to occupational exposure (i.e., large exposures to workers). Interestingly, despite indications that antimony trioxide could interfere with embryonic and fetal development, the outcome of pregnancy in women treated with antimony compounds for leishmaniasis has not been studied (source). Additionally, according to the European Chemicals Agency (ECHA), antimony may damage fertility or the unborn child. Also, it may cause cancer, harm breastfed children, and damage organs through prolonged or repeated exposure.
Third, organochlorines are synthetic pollutants to humans. Thus, many organochlorines are linked to endocrine disruption or cancer in experimental assays (source). They also raise concern about their adverse reproductive effects in humans (source). Like antimony, organochlorines enhance the flame retardancy characteristics and the impact strength characteristics in PVC.
Heavy metals in PVC yoga mats
These substances in your polyvinyl chloride yoga mat can enter your body through skin contact and inhalation. In addition, they may contaminate your body via ingestion of the dust containing heavy metals.
I do my best to minimize exposure to heavy metals because of their cumulative effects. Lead can cause neurological, cardiovascular, renal, gastrointestinal, hematological, and reproductive effects (source). The International Agency for Research on Cancer (IARC) has classified them as “probably carcinogenic to humans.”
And cadmium is linked to reduced mineral density in bones, preterm labor, kidney disease and damage (source). Also, the International Agency for Research on Cancer (IARC) has classified it as “carcinogenic to humans.”
Unfortunately, heavy metals are transferred by maternal blood to the fetus via the placenta, and later through breast milk (source).
In sum, it does not seem that they add heat stabilizers to PVC to benefit human health. What about lubricants and plasticizers?
Lubricants in plastics reduce friction during processing.
Apparently, there are external lubricants and internal lubricants. While the former reduces friction between the PVC and the processing equipment, the latter work on the PVC granules (source). It looks like there is no way for PVC yoga mats to work around these either.
“With PVC, typical external lubricants are stearic acid and its calcium, lead, cadmium, and barium salts, myristic acid, hydrocarbons such as paraffin wax, and low molecular weight polythene and certain esters such as ethyl palmitate… Amongst internal lubricants used for PVC are amine waxes, montan wax ester derivatives, glyceryl esters such as glyceryl monostearate, and long-chain esters such as cetyl palmitate.” (2)
Among these, my concern lies with lead and cadmium salts for the reasons I stated in the heavy metal section.
Plasticizers make a polyvinyl chloride yoga mat flexible.
First of all, a plasticizer makes plastic flexible, resilient, and easier to handle. Therefore, a plasticizer is crucial in PVC yoga mats.
While the most common plasticizers are phthalates, many products boast that they are “phthalate-free.” This is because phthalates have a bad reputation as endocrine disruptors (source). Moreover, some phthalates are so toxic that in 2012 the US government enacted a law to restrict their use in children’s toys and other children’s items (source). In addition, they have been linked to birth defects, asthma, neurodevelopmental problems in newborns, fertility issues, obesity, and cancer (source).
So, is a phthalate-free polyvinyl chloride yoga mat safe?
Well, I encourage you to always ask what the manufacturer uses instead of phthalates. For example, other plasticizers are adipates, glutarates, sebacates, phosphates, polymerics, trimellitates, and epoxy compounds. (3) The good news is that none of these seems to be as toxic as phthalates. However, they may have limited safety data, meaning that they do not know enough about their safety yet. And most of the time manufacturers do not tell us what they use instead of phthalates. So “phthalate-free” may sound good, but it may not mean safer.
The life cycle of PVC yoga mats produces dangerous byproducts.
According to the European Chemicals Agency, vinyl chloride – the main ingredient in PVC – is a human carcinogen. Thus, the first report of liver cancer induced by vinyl chloride was in 1974 (source). Since then, new research has demonstrated the carcinogenicity of VC to other organs and at lower concentrations. I have no scientific evidence that one can get cancer from regular yoga sessions on a polyvinyl chloride yoga mat.
Additionally, one of the concerns with PVC is the generation of carcinogenic dioxins, byproducts of the manufacturing and disposal processes. Thus, the EWG rates dioxins 10 out of 10 (with 1 as the least toxic) due to high cancer concerns.
Because PVC is not biodegradable, the only way to get rid of it is to burn it. When burning, chlorine produces dioxins that end up in soil, fish, animals, water, air, and, ultimately, in humans. Dioxins are persistent (they do not break down easily in the environment) and bioaccumulative (they build up in our bodies). As a result, they may cause reproductive and developmental problems, damage the immune system, and interfere with hormones.
Therefore, US Environmental Protection Agency regards dioxins as highly toxic persistent organic pollutants. And the Stockholm Convention on persistent organic pollutants emphasizes the importance of limiting the processes that produce dioxins.
I think those are good reasons to avoid PVC yoga mats. Clearly, we cannot get rid of all plastics, but let us do what we can by making informed decisions. So, what yoga mat do I use?
I recommend a cork yoga mat instead of a polyvinyl chloride yoga mat.
Some manufacturers have caught on to the idea that consumers are concerned about exposure to toxic chemicals. Consequently, they get very crafty with their product descriptions. You might have seen claims like phthalate-free, lead-free, BPA-free etc. It does not mean, however, that the mat is free of PVC. So, always ask the manufacturer by email whether the yoga mat you want to buy is free of PVC.
Other popular mats nowadays are TPE yoga mats and eco-friendly yoga mats. I have tried them and described my experience in my Eco-Friendly Yoga Mats: Safe or Toxic? post. You will also learn what TPE material is.
So, after trying several yoga mats, I ended up with a sustainable cork yoga mat by Scoria. What I like about this biodegradable non-toxic yoga mat is that it is thick, not bulky, and not slippery. In fact, it has rubber backing against sliding. I also like the unique design of this non-PVC yoga mat, which contributes to my general feeling of ease. Read my review of the Scoria yoga mat to learn more about it.
Summary about PVC yoga mats
In conclusion, most yoga mats are made from polyvinyl chloride (PVC). This plastic is toxic during manufacturing and exposure. It is unclear whether you can actually get sick from using your mat. However, there is enough evidence to be concerned about increased risks. As consumers, we are exposed to PVC through inhalation, dermal absorption, and ingestion.
Personally, I stay away from any PVC yoga mats for my yoga or Pilates sessions. If you already own a polyvinyl chloride yoga mat and want to be on the safe side, you might consider replacing it with a safer option. For example, this Scoria mat is a combination of cork and natural rubber. I have used it for years and love it!
As always, I invite you to visit my shop with options of non-toxic products for home, skin, and wardrobe. Also, you can book a consultation with me and join the Savvy Consumer Circle to learn how to live healthy and have fun.