Love it or hate it, that ‘new yoga mat smell’ may be bad for your health. While some natural yoga mats have a perfectly benign ‘new’ smell when you first unroll them, this smell can also be caused by the off-gassing of a variety of chemicals, some of which are classed as carcinogens.
If you’re looking for our top picks as far as yoga mats go, two companies, in particular, stand out: Liforme and Manduka. I’ll get into the nitty-gritty as to why below.
Without further ado, I’ll quickly run through some of the worst offenders to watch out for in yoga mats.
- VOCs and PAHs
- The ‘yoga mat chemical’, AKA azodicarbonamide
- Phthalates, PVC, and synthetic latex
- The environmental impact of yoga mats
- Materials – what are yoga mats made of?
- FPC™ – the future of eco-friendly yoga mats?
VOCs and PAHs
Chemicals such as volatile oil compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) are emitted as a breathable gas from PVC yoga mats, as well as from carpets, furnishings, paint, cleaning supplies, printer ink, and other household products. As I mention time and again at Leaf Score, concentrations of VOCs inside the house (and the yoga studio) can be ten-fold higher than outdoors (R).
These chemicals can cause headaches, nausea and dizziness, nasal irritation, allergic reactions, neurological problems, liver and kidney damage, cancer, and possible even fertility problems and miscarriage. As if that wasn’t bad enough, some of these chemicals are greenhouse gases, meaning that they contribute to climate change (which has its own negative effects on health).
VOCs include a variety of chemicals used as antimicrobial treatments (which are increasingly common in yoga mats), stain and soil repellents, anti-static treatments, adhesives, artificial dyes, and flame retardants like organophosphate flame retardants (PFRs). While picking up an older, second hand yoga mat in a thrift store helps keep it out of landfill, these older mats are likely to be especially bad for off-gassing.
PFRs and pregnancy
As someone who plans on trying to conceive in the next little while, I’m particularly concerned by the fact that PFRs have recently been linked to female reproductive health problems. Indeed, a study in the journal Environmental Health Perspective revealed that these chemicals in yoga mats may make it harder to get pregnant and have a healthy pregnancy (R).
The researchers assessed data from 211 women using IVF to get pregnant and found that women with the highest levels of PFR metabolites in their urine were 31 percent less likely to have success with embryo implantation. These women were also 10 percent less likely to achieve fertilization, 41 percent less likely to get pregnant, and 38 percent less likely to have a successful live birth.
The ‘yoga mat chemical’, AKA azodicarbonamide
Now known colloquially as the ‘yoga mat chemical’, azodicarbonamide (ADA) is a synthetic chemical with a crystalline structure at room temperature and a yellow-orange color. It is predominantly used in the rubber and plastic industries as a chemical foaming agent. When it is mixed into polymer plastic gel it creates tiny gas bubbles, resulting in PVC, polyolefins, and natural and synthetic rubbers that are strong, light, spongy and malleable.
ADA is also used in beer-making processes and is added to cereal flour for its whitening effect and to bread flour to remove the need for traditional proofing where natural yeast is used to make bread rise. As such, many fast food restaurants and bakeries make bread and other baked goods with ADA.
In the U.S., ADA is still used in a wide variety of products, including food. Despite campaigns in recent years calling for Subway, Wendy’s, McDonalds, and other companies to stop using the chemical, according to Environmental Working Group, ADA is still present in hundreds of supermarket items, as well as in rubber and leather goods, and PVC products including yoga mats.
Production of the chemical and its use in foods is banned in the European Union and Australia, although it may still be imported for use in non-edible products. In Singapore, companies who use ADA are subject to massive fines and even jail time. (This might be a good time to read my take on Why Consumer Safety Regulations Matter!)
Phthalates, PVC, and synthetic latex
Phthalates are another chemical often found in yoga mats. This chemical is used to make PVC flexible, but it has been shown to leach out of materials when they become warm, making it a particular problem for anyone doing Bikram yoga. Phthalates can attach to dust and are then breathed in. Phthalates have been linked to a range of troublesome health issues, including infertility, menstrual problems and other conditions and diseases (R).
Even if your yoga mat has a ‘natural’ surface, the backing, padding, or bulk of the mat might be made of synthetic latex (a suspected carcinogen) or vinyl, urethane, 4-phenylcylclohexene, or PVC. And, even if a mat itself isn’t riddled with toxins, it may have been manufactured using harmful chemicals like chlorine gas, ethylene dichloride, vinyl chloride, mercury, and dioxins, which are then released into the environment.
Some companies have started using polyester in yoga mat construction, claiming that this is healthier than PVC. While they’re right in some senses, what they fail to acknowledge is that polyester production is energy intensive, leading to significant greenhouse gas emissions, including carbon dioxide, as well as nitrous oxide, hydrocarbons, sulfur oxides and carbon monoxide, acetaldehyde and 1,4-dioxane (another potential carcinogen).
Polyester production also generates water-borne emissions, including dissolved solids, acids, iron, and ammonia. So, even though a polyester product may be labeled as ‘green’, this is likely less to do with the environmental impact and more to do with the end product not off-gassing toxic chemicals.
The environmental impact of yoga mats
Sadly, more common certifications such as Oeko-Tex 100 do not factor in the impact of manufacturing processes and only assess the end product. Oeko-Tex 1000 is better, but few fabric manufacturers carry this certification.
Some of the nasties found in yoga mats or involved in their production include:
- Azodicarbonamide (ADA)
- Pesticides, herbicides, and fertilizers (in ‘natural’ fiber mats)
Minimizing toxicity from yoga mats means choosing a mat made with natural materials free from potentially harmful chemical residues. There are other reasons, aside from possible toxins, to avoid synthetic materials and choose natural, organic yoga mats. Supporting this kind of organic agriculture is one of the best ways to fight climate change and encourage biodiversity.
Organic agriculture promotes healthier, stable, microbe-rich soil that is less prone to wildfires and which itself acts as a carbon sink. The Rodale Institute Farming Systems Trial (FST) soil carbon data (which covers 30 years) clearly shows that regenerative organic agricultural practices are the most effective strategy we have to combat climate change (R). In addition, organic agriculture reduces the amount of synthetic fertilizers, pesticides and genetically modified organisms (GMOs) in the environment and conserves water.
Materials – what are yoga mats made of?
Yoga mats continue to be made predominantly with polyvinyl chloride (PVC). This synthetic material is cheap, usually fairly durable, has good ‘stickiness’ to reduce slippage, and also provides good ‘give’ or ‘sponginess’, for added comfort. Unfortunately, PVC is not eco-friendly and is often riddled with toxins, as mentioned above. If you plan to do yoga with your toddler or child using a mat, it’s best to avoid PVC as this material can cause adverse health effects (see more about PVC in crib mattresses).
According to TreeHugger.com, every kilogram of PVC requires roughly 17 kg of abiotic materials, mostly petrochemicals, to produce, and uses around 680 liters of water in its manufacture. A kg of PVC also requires 11.6 kg of air, which becomes greenhouse gases and other gases.
So, a PVC yoga mat weighing in at 3 pounds (1.36 kg) has an environmental imprint (for manufacture only) of 23 kg of petrochemicals and minerals, 925 liters of water, and 15.8 kg of air. Add to that the energy involved in shipping the raw materials (petroleum) around the world and shipping the mat to you, and an organic cotton mat made and shipped from India, or a natural rubber mat from Taiwan, starts to look even better.
Natural yoga mat materials
Given the risk of exposure to toxins such as ADA, PFRs, parabens, and phthalates in PVC, and the high energy consumption required in PVC production, it’s smart to choose a yoga mat made with natural materials.
Eco-friendly materials tend to be a little more costly than cheap PVC and can degrade quickly without proper care. But it’ll be easier to get in the zone if you’re not inhaling toxic gases or worrying about your impact on the planet.
Some good options include yoga mats made with:
- Organic cotton – excellent for sweat absorption (improving grip in Bikram), but not so good for ‘give’ or ‘sponginess’
- Wool – yes, it may seem an odd choice for a yoga mat, but a layer of wool over a natural rubber backing offers excellent grip, comfort, and natural antimicrobial and flame-retardant properties. Wool felt may also be used inside two layers of rubber or other material, for extra cushioning
- Recycled rubber – good, but not great, grip potential. Not always suitable for anyone with a latex allergy and possibly riddled with heavy metals and toxic chemicals (natural rubber may be a great option though!)
- Cork – provides naturally good grip that improves as it absorbs moisture. Naturally antimicrobial and easy to keep clean, but can crack if not properly cared for
- Jute – naturally antimicrobial, but often blended with Polymer Environmental Resin (PER) to provide extra grippiness (but not much ‘give’)
Even when doing Bikram, a good quality yoga mat made with the right materials should provide sufficient stickiness to stop you slipping. If you find you need to use a towel to wipe down your mat and prevent slippage, you might want to consider a cork, cotton, or wool mat next time. Some rubber mats have a closed-cell surface on one side of the mat and an open cell surface on the other. Picking the right surface can make a big difference to moisture absorption and slippiness.
Cotton yoga mat pros and cons
Cotton yoga mats are an excellent option for use on carpet or on top of a grip mat or other yoga mat. They offer no real grip by themselves, but are absorbent, easy to clean, and are non-toxic. Be sure to choose organic cotton as conventional cotton is grown using vast amounts of pesticides and water, which makes it rather less eco-friendly than it might at first seem. Unlike rubber mats, cotton mats don’t deteriorate in direct sunlight or with heat and are likely to last a good 15 years or more, after which they can easily be repurposed as a rug, runner, or for other purpose at home.
Wool yoga mat pros and cons
Some companies are starting to offer yoga mats made with a layer of wool or cotton over natural rubber backing, or a wool/cotton blend. These mats are excellent options for anyone who wants a little more thickness and comfort to their mat, especially if you like to practice in a cooler room and enjoy some insulation from the ground up. Wool is naturally flame retardant and antimicrobial, as well as being absorbent, so it can be a great option for sweatier yoga practitioners.
TPE and PER for yoga mats
Watch out for yoga mats promoted as eco-friendly and non-toxic but made with petroleum materials such as PER (Polymer Environmental Resin) or TPE (Thermoplastic Elastomer). These materials may be better than PVC in terms of energy requirements and some toxicity, but they are far from natural and may still contain toxins other than phthalates.
What is TPE?
TPE is a synthetic material with no specific composition, meaning that a TPE mat could be made from rubber, plastic, a mixture of the two, or from something else entirely. The big selling point of TPE seems simply to be that it’s not made from PVC.
Mat manufacturers often promote TPE as being free of bisphenol-A (BPA), PVC, lead, phthalates, dioxins, and other problematic chemicals, but they may still leach synthetic estrogens, even if they aren’t exposed to high temperatures, humidity, and sunlight (as yoga mats often are, particularly in Bikram).
One TPE mat, by Kulae, is made from styrene-butadiene-styrene block copolymers (SBS). What does this mean? Well, it sounds very much like a composite of styrene, a possibly carcinogenic material made from ethylbenzene, and butadiene, another potentially carcinogenic material, this time made from carbon and hydrogen in an energy intense steam cracking process requiring temperatures as high as 900 degrees Celsius. So, in reality, TPE could be just as environmentally damaging and just as bad for our health as PVC.
Indeed, results of tests by a researcher at the University of Texas-Austin show that almost all types of commercially available plastics (which includes TPE) leached synthetic estrogens, with some of the BPA-free plastics releasing synthetic estrogens that were more potent endocrine disruptors than BPA itself (Bittner, CertiChem). As mat manufacturers rarely reveal the precise nature of the TPE in their products, we just can’t be certain of their safety.
Case in point, Jade yoga mats, which are advertised as non-toxic and eco-friendly, were found by a German agency to contain nitrosamines, chemicals linked to cancer. The company has said they’ve revised their manufacturing processes, but no additional third-party testing has been conducted.
I decided not to include Jade Harmony yoga mats in my recommended products in part because of these test results and because the company closely guards the exact make-up of its mats, only stating that they contain natural and man-made materials and are free from PVC, heavy metals, and phthalates. This is a real shame, as Jade Harmony Yoga Mats appear to be one of the few yoga mats to meet the performance needs of most practitioners while being PVC-free and (likely) relatively non-toxic.
All this said, if you have been coveting a Jade Mat, or even a Liforme or Manduka Pro Mat, and not having the mat means you’re practicing yoga less, get the mat. After all, it is almost certainly better for your health to practice yoga, even on a mat that may have some degree of undesirable environmental and health impact than it is to not practice and instead feel stressed and unhealthy through lack of exercise.
The team that tested the Jade mat and others, Ökotest, was looking for:
- Nitrosamines – present in rubber vulcanized through the use of some accelerator chemicals
- Formamide – found in yoga mats made of the foam rubber EVA
- 2-phenyl-2 – a potential allergen used in plastics manufacturing
- Toxic azo dyes – used to dye cotton and other fibers
- Insecticides – found on the surface of virgin wool
- Chlorides – used in the production of PVC
Researchers were also looking for endocrine disruptors called nonylphenol ethoxylates which may be involved in the production of cotton and which enter waste water and damage aquatic organisms.
FPC™ – the future of eco-friendly yoga mats?
One exciting innovation in yoga mat material technology comes courtesy of a Taiwanese company called eTouch Innovation Inc. This company developed an eco-friendly material called Fiber Particulate Composite (FPC™) made mainly from agricultural waste.
FPC™ contains fiber as its main ingredient, mixed with a proprietary Compatibilizer™ made from converted starch derived from rice waste products. FPC™ is made without adding any man-made chemicals and can be mixed with recycled plastics where it serves as a binder. This means FPC™ could be used to make textiles from recycled plastic rescued from the oceans and landfill. And, because the rice used in the product is waste from the food industry, it does not create competition for food sources and actually reduces air pollution (because the agricultural waste would otherwise be burned).
If a product is 100 percent FPC it is also 100 percent biodegradable and compostable, and as the material uses waste products, it creates a closed loop system that requires very little energy input to upcycle materials into new goods. This probably makes the FPC Yoga Mat designed by eTouch the world’s most eco-friendly yoga mat.
The FPC yoga mat is half natural rubber and half bio-composite material, which uses 100 percent natural ingredients mainly from agricultural by-products such as rice husk, rice straw, bamboo chips, and coffee residues, with no man-made chemical additives. The mat is similar to, if not better than, standard yoga mats for tensile strength, slippiness, durability, and weight. It is 100 percent recyclable, biodegradable, and bio-renewable, completely non-toxic and environmentally friendly, even after end-of-life. The mat also has the lowest carbon-footage for any yoga mat.
The FPC yoga mat is manufactured in a reversible purple and gray design that is 4.5 mm thick and 71″ long, with a standard 24” and extra wide 26″ width. Unfortunately, the mat does not yet seem to be available to the public.
While we’re on the topic of yoga mats, here are the companies I recommend that make eco-friendly, non-toxic options.