The Answer: Pleather (polyurethane-based).

Context

While fashion trends are ever-changing, new material innovations bring about interesting shifts in consumption. Looking at footwear and baggage, historically leather-based products, the introduction of imitation and technical materials has shifted that trend. For example, while the volume of leather footwear exported (and consumed) remained stable between 2000 and 2010, the volume of rubber and plastic footwear exports has more than doubled. Leather may be seen as a more authentic and unique – attributes that appeal to Gen Y – but pleather offers a convenient, cheaper alternative. Naturally, we wondered how the comparison holds up on a sustainability level, so we compared leather and pleather to see which is greener.

How We Measured It

This is one of the most challenging “This or That” explorations to date, since establishing a useful comparison is fraught with difficulties.

Firstly, finding an appropriate metric of comparison is difficult. We often consider carbon dioxide emissions because they are both straightforward to quantify and they exacerbate a widely-recognized issue (climate change). But, in the case of leather and pleather, toxic pollution may be the most important consideration. Unfortunately, quantifying and comparing the effects of different types of toxic pollution is in no way straightforward (how do you compare toxic pollution to climate change contribution?).

Secondly, defining appropriate boundaries for the production of leather and pleather also presents some challenges. How should the impacts of raising cows be shared between meat-production and leather-making? For the sake of argument, we’ve allocated all of the impacts from raising cows to meat-production, and treat the cowhide as an input to the leather-making process with no associated impact.

So in this case, while it’s still quite subjective, our metric for comparison is toxic pollution. And only the manufacturing stage of the lifecycle is considered, since it has the most significant differences between the two choices. For leather-making, it means manufacturing leather from hides and, for pleather-making, it means manufacturing pleather from a petroleum base.

Why Pleather?

It is easy to understand why the answer “pleather” might be surprising. Sure, we know raising cows for meat is an incredibly resource-intensive way to produce food… but if the world is going to continue eating beef anyway, shouldn’t we be resourceful and use everything that comes with the cow, including skins? Definitely not. Finished leather is nothing like the skin that comes off the animal.

Modern, industrial leather-making involves the use of highly toxic chemicals to clean and tan hides. There’s a reason that many former leather-making sites in the U.S. are classified by the EPA as Super-fund sites, or “uncontrolled hazardous waste sites”. It may feel wasteful not to, but converting cow skin to leather is so toxic that it would be better for our ecosystem (including our own health) to simply let cow skins biodegrade. And because we’ve ignored the impact of raising the cow before the leather-making process in this analysis, things can only get worse for leather.

Pleather production, on the other hand, starts from a petroleum base and becomes pleather through a number of energy-intensive processing steps. Pleather is most frequently made of polyurethane (PU) and while its production contributes to climate change through carbon dioxide emissions, its toxic pollution is dramatically less. You might spot some polyvinyl chloride (PVC) pleather out there, which (like leather) comes with considerable toxic pollution baggage. But since PU is typically used for clothing and upholstery because it is softer, more flexible, and more breathable than its PVC counterpart, it becomes the clear alternative to leather.

“But I can keep that leather jacket for generations,” you say! Determining whether leather products are more durable than pleather products could tip the scale. Today, high-quality leather and pleather products can have similar durability. But if leather products last significantly longer, even though they require more maintenance, then leather may become the better choice.

That being said, the very best option is to avoid the environmental costs associated with that grimy manufacturing stage altogether: go vintage and buy second-hand pleather or leather goods. Or go for quality over quantity by maintaining a small collection of multi-purpose, durable shoes and bags. But if you’re in the market for a new pair of shoes, jacket, or sofa, the environmentally conscious choice is PU pleather over PVC pleather or leather.

Implications

In making material choices, a “natural” source isn’t always the answer. But with new technologies making imitation materials more convincing than ever, it’s getting easier to fake it. And if you crave the luxury and nostalgia of the real deal, a growing trend for salvaged materials means you can get that rough lux appeal while still being green.

Sources

http://www.slate.com/articles/health_and_science/the_green_lantern/2007/12/whether_the_leather_be_pleather.html

http://www.mitchellfauxleathers.com/default/viewpoint/read.aspx?id=7

http://leathersustainability.weebly.com/

http://grist.org/article/tongue-tied/