PVC or polyvinyl chloride is a synthetic plastic polymer (compound). It is the third most widely produced kind of plastic and is commonly used as a material for yoga mats. This plastic polymer is made from both salt and petroleum. The plastic itself is considered safe for use by people, however it is the addition of additives like heat stabilizers, lubricants and plasticizers that PVC yoga mats become a source of concern.
Heat stabilizers are used to keep the material from breaking down when exposed to heat or UV light, as well as protecting the PVC in processing and eventual use. The heat stabilizers used in the production of PVC consist of heavy metals like lead, organotin (or-gan-no-tin) compounds, organochlorines and a few other materials. Lead accumulates in the body and becomes detrimental to health over time, affecting a number of organ systems. Organotin compounds are toxic to humans at the cellular level. While organochlorines are endocrine disruptors, meaning they affect our hormonal systems which can cause cancer, birth defects and other developmental factors. And that’s just one variety of additive…
Lubricants are added to the mixture to prevent friction and the wear and tear on the material from the manufacturing equipment. Among the substances used for lubrication like paraffin wax, low molecular weight polythene, a couple varieties of esters, amine waxes, montan wax, and ester derivatives, the greatest cause for concern lies once again in the use of heavy metals like cadmium salts or potentially lead. Cadmium exposure and ingestion is linked to reduced mineral density in bones, preterm labor as well as kidney disease and damage.
As for plasticizers they make the PVC yoga mats flexible, easier to handle and more resilient. Phthalates tend to be one of the more frequently used plasticizers, however more and more products are advertising themselves as phthalate-free due to the endocrine disrupting nature of the chemical. Many of the chemicals used in lieu of phthalates are considered safer, however many of these substances have little safety data, so it is unclear how much safer they may be.
There are very few facilities that accept and recycle PVC yoga mats, so for the most part they are destined to break down into smaller plastics within a landfill and potentially leach their toxic components into the ground and worst case scenario, groundwater.
TPE or thermoplastic elastomer compounds are a mixture of plastic and rubber compounds (either synthetic or natural rubber). They are typically revered for having the desirable flexibility of rubber and ease of manufacturing of plastics. Hence, the application of this material fits the needs of a yoga mat.
There can be some potential for creating new TPE products using recycled TPE products, but this often happens in closed-loop systems and is not as readily accessible to most curbside recycling collections.
The ecological impacts of this material through its manufacturing tends to be the most intense part of its product lifespan (the impacts a product has on the environment from the gathering of raw materials, processing and eventual disposal).
To create this compound, non-renewable resources such as fossil fuels are utilized to make the plastic component. This requires the environmentally intensive extraction of oil which creates emissions in the process of extracting a substance that will later create more emissions in the processing portion of its product lifespan. Just the extraction and processing portion of the baseline material in TPE results in the production of greenhouse gases or GHG emissions. And that’s before ever combining it with rubber. Assuming the petroleum product is mixed with a synthetic rubber compound as opposed to a natural rubber, this adds additional environmental impacts in the form of more energy usage for processing, more raw non-renewable resources as well as emissions and waste products from manufacturing.
There are 6 different chemical compound variations of TPE materials, each utilizing slightly different ingredients in their composition and thus different combinations of effects on the environment.
Some companies are utilizing more recycled materials than in the past and there is a movement towards making more “sustainable” plastics, however considering the enormous impacts plastic is having on our planet and especially our oceans, it is still generating fossil fuel emissions and creating an opportunity for more plastic to be made and to eventually break down into smaller, more difficult to manage microplastics. In the short term, these materials can be more affordable but looking long term, the true cost is put on our ecosystems.