Some Plant-Based Leathers Might Not Be So Eco-Friendly After All

Are plant-based vegan leather manufacturers telling the whole truth about how their materials are made? We're discussing the most recent revelations of lab tests done on these materials, with some surprising discoveries about certain types of plant-based leathers.

As you may recall from our last article on plant-based leathers, we were very optimistic about the innovations in the field including Desserto cactus leather, apple leather, and Vegea wine leather. 

We think it's important to avoid purchasing new animal-skin leather out of respect for animals as sentient beings (we wouldn't wear a purse made of human skin either). We've often fought back against claims of animal leather's supposed sustainability due to the inherent cruelty and animal suffering involved in procuring the raw material, the ties of the leather industry with the industrial beef industry and to deforestation of the Amazon rainforest, and the list of toxic chemicals employed in the tanning process used by most producers of leather. 

We believe that there's room for a world of innovation in using plant materials to create alternatives to both animal-derived leather and petroleum-derived synthetic leathers. So we were beyond excited to discuss all of the new types of plant-based leathers coming to market.

But, recent findings have shown that questionable substances are being used to bring these fabrics to life. Some of the vegan leathers that we spoke about in previous articles even have been found to contain toxic chemicals that are banned from use! Although this article may seem contradictory to our past articles, we think honesty is the most important thing, and that we need to admit the faults in our own field before anyone else without bias. It'd be ignoring emerging facts to not reveal this information. 

Polyurethane Content

We knew that there was polyurethane used in many types of new vegan leathers. We specifically asked brands and producers about this and revealed as much as we could find out to our readers.

We thought that despite this, the materials showed promise.

We still believe that plant-based leathers, or plant-plastic hybrid leathers, are an improvement compared to fully synthetic leather due to the reduced environmental impact of the raw materials used in production. Although they still use some plastic, it is less than what would be used to make 100% synthetic leather, and often the plant matter in these leathers would otherwise be considered a waste product and is therefore recovered from the waste stream and put to better use.

We were especially excited about the stunning green opaque material called Desserto, which we thought contained a greater percentage of cactus than plastic polymer. 

Recently, however, information has come to light that has challenged our view on certain plant-hybrid leathers, specifically and quite unfortunately, Desserto.

We had reached out to Desserto months ago asking for the full chemical component list of the final product. They were very kind in their response but told us that it was a proprietary secret, although only non-toxic chemicals were used, and the material is PVC-free.

We imagined that the material contained some polyurethane or other types of plastic, hence the secrecy and lack of full transparency. But we have recently found out that the material is MAINLY polyurethane. The Circular Laboratory was able to find out that the main ingredient in Desserto cactus leather is polyurethane, making up 65% of the final product, while cactus only makes up 30% of the material by weight. They were able to find this information in a material database on Future Fabrics Virtual Expo's website, but it has since been removed.

Desserto under a microscope. (a) is the top polymeric coating, (b) is the foamed polymer and natural material layer and (c) is the synthetic textile backing. Credit: Coatings Journal

As eye-catching as the final product is, we don't think it is honest to hide (or refrain from mentioning) the real, entire chemical composition of materials from consumers, leading people to think they are buying a product that is more environmentally sustainable than it really is.

Which Vegan Leathers Contain Undisclosed Toxins?

While we had a pretty good idea about the polyurethane content in vegan leathers before, we were shocked to find out that four types of vegan plant-based leather that we had previously discussed (in a positive light) contain explicitly banned substances!

The FILK Freiberg Institute, an independent institute that specializes in the testing of leather and polymer composite materials, published a peer-reviewed study in the journal Coatings, which brought to light previously unknown information about these materials.

The study found that some vegan leather alternatives contained traces of banned chemicals, notably Desserto, Pellemela (Appleskin), Vegea, and Piñatex, which are part of a group of plastic-coated textile leathers. Desserto cactus leather was the worst offender, containing five restricted substances including butanone oxime, toluene, free isocyanate, an organic pesticide called folpet, and traces of a phthalate plasticizer. In the other aforementioned textiles, toluene, plasticizers, and the solvent DMF were found. But, the article does not state the exact quantities of the banned chemicals which were found.

We were deeply saddened by this news, as we had been excited about the prospects of each of these materials. Although we love that Desserto uses cactus that is harvested without harming the plant, and the others use plant waste left behind from food production (including skins, stems, etc.) from apples, grapes, and pineapples, there's no reason to use banned chemical substances in a vegan product marketed as eco-friendly to health-conscious consumers. These substances could be transferred to our skin when touching the materials, and could therefore enter our bodies, just like with the tanning chemicals used in leather production. This could cause health problems or allergic reactions. That's far from what we want to be promoting to our customers!

We hope that the makers of these materials will acknowledge this problem and remove these chemicals from their products immediately. We'd love to be able to go back to promoting these products if they can be proven to not contain banned substances.

Biodegradable or not?

"Partially biodegradable" seems positive at first glance without really thinking about what it means in practice. I fell prey to this thinking too, imagining that the material would be able to break down in nature more quickly than if it were completely made from synthetic fabric. 

Desserto told us back in 2020 that the material was partially biodegradable, and I relayed that information from them in our blog post on plant-based vegan leathers. But it has been pointed out that the polyurethane content in the material cannot be separated from the plant material, and therefore the entire material is unable to be composted without leaving behind a plastic residue.

If the idea of being "partially biodegradable" is greenwashing, then we need to take a step back rather than continuing to praise every new plant-based leather that comes to market containing petrochemicals and plastics.

If a product is truly biodegradable, there's no need to recycle the material as it can easily be broken down in nature. But if it isn't, we need transparency and honesty regarding its real end-of-life destiny. If it can't biodegrade or would be damaging to the soil, these brands could implement a send-back recycling program for their products. That way, their materials can continue to be reused rather than being landfilled.

Microplastics

There's also a concern regarding microplastics from the breakdown of synthetic and plant-plastic combination leathers. Plastic-coated textile leathers can release microplastics, which can crumble off of the material over time. 

What is the solution?

Nowadays we are much more excited about the prospect of 100% plant leathers than plant-based leathers that incorporate plastic. Many people are disappointed to find that although new vegan leather options incorporate plants, they still have a high polyurethane and petrochemical content. We must admit that although vegan leathers have come a long way, many still have quite a way to go before they are completely beneficial for the environment. There's still a need for more innovation in the field. 

On the bright side, there is ever-growing interest in cruelty-free and plant-based alternatives to leather, especially as veganism and sustainability are becoming priorities when making purchasing decisions. We are sure that in the future, manufacturers will rise to the occasion and work out how to replace the polyurethane and other petrochemical substances in the plant-based leathers currently on the market.

We will continue to sell only cork products for now, as cork itself doesn't require any chemicals for processing into leather sheets. It's among the most sustainable leather alternatives as it is a 100% natural product. It is carbon negative from harvest to disposal, and is biodegradable and recyclable. It has unique properties due to its waxy cellular structure that can't be matched by any synthetic materials.

The Life Cycle Assessment process of cork, in which all stages of the product's life were analyzed: spanning forest management activities, cork crushing, transportation, and the industrial process. Credit: Amorim Cork Composites

We do hope to branch out to more than just cork products eventually, with natural hemp bags at the top of our list. We also will be following up with more research into the mushroom leather Reishi, which is a 100% natural leather that rivals animal leather in its characteristics, as well as MIRUM from Natural Fiber Welding. According to Natural Fiber Welding's founder, MIRUM has the lowest resource and carbon footprint and the lowest ecological impact compared to all other leather-alternative textiles. It uses zero plastic: no PU, no PVC, no EVA, and no petrochemicals. MIRUM is made from virgin and recycled plant fiber, including cork powder and coconut husks! In March 2021, the first commercially-available collection of MIRUM received the USDA 100% Biobased certification.

MIRUM has been tested by the USDA, for biogenic/biobased carbon content, confirming that it contains no petrochemical ingredients. It is 100% biobased, meaning that it contains carbon derived only from plants (organic carbon derived from current day carbon cycles). Credit: Natural Fiber Welding

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We will be sure to keep you posted on all the latest news in the field of plant-based leathers, even if the news isn't what we are happy to report. We think that we deserve to be told the whole truth in order to make informed decisions, whatever those decisions may be.

Let us know what you think about this article below! We'd love to hear your thoughts on the subject.

All the best,

Lindsay