Most wetsuits are made from neoprene, along with a few other ingredients. But what is neoprene anyway, where does it come from, and is it an environmentally friendly material?
Wetsuits don’t grow on trees. Actually, some of them kind of do, but more on that later. Generally, it would be truer to say they’re dug out of the earth, a bit like all those filthy Orcs in the Lord of the Rings.
Wetsuits are made primarily from polychloroprene, better known as neoprene, a synthetic rubber material. Pellets of polychloroprene are melted down, mixed with foaming (or blowing) agents and pigment (carbon black), baked in an oven, and thus infused with air bubbles. This process creates stretchy sheets of neoprene foam with excellent insulating properties.
What are wetsuits lined with?
This neoprene foam is then laminated to a stretchy fabric lining, normally nylon or polyester. The resulting panels are stitched (and/or glued, blind-stitched, taped, maybe even heat-sealed) together in wetsuit form.
You may hear talk of single-lined and double-lined neoprene. What’s the difference? Essentially single-lined neoprene has only been lined with jersey fabric on the inside. The outside will have been heat-sealed, which is what creates the slick, shiny surface on some wetsuits.
This smooth exterior, often called smoothskin, is more water-repellant and wind-resistant than its jersey-lined equivalent. However, it’s also more susceptible to damage, particularly from sharp edges such as fingernails, surfboard fins, etc. Surfing wetsuits will feature a few single-lined neoprene panels at most, typically on the torso and back. Many have no smoothskin at all.
Most mid-to-high end wetsuits nowadays also feature some sort of thermal lining on the inside, containing heat-reflecting and fast-drying metallic fibres. “Metallic” sounds hard and cold, but these linings are generally more of a fuzzy fleece material. Titanium inner liners are the most popular, though what is marketing spin and what is science is perhaps debatable.
Is limestone neoprene “eco”?
The polychloroprene chips are made by “polymerising” chloroprene – this is essentially the process of binding together small molecules (monomers) into macromolecules (polymers). But where does chloroprene come from?
Traditionally it came from petroleum derivatives (such as butadiene), but these days it usually comes from limestone. This sounds much nicer than petrochemicals – limes go in gin & tonics, while stones are all around us, including on the beach – but it still isn’t exactly “eco” or sustainable, despite what some brands may say.
First, the limestone has to be quarried, or dug out of the ground. Then it has to be heated at extremely high temperatures (2000°C plus) to be turned into neoprene. Both of these are carbon-intensive and destructive processes.
In environmental terms, limestone does have several advantages over petrochemicals. Most obviously, it doesn’t directly rely on or support fossil-fuel extraction. Oil spills are much more damaging and harder to clean up than limestone spills.
It’s an improvement on petrochemical neoprene, but still, it’s far from a clean process, and not the panacea it’s sometimes presented as being.
Natural rubber wetsuits
There is an alternative though, and that’s natural rubber. All Patagonia wetsuits, for instance, are now made with Yulex® natural rubber, a process the brand has pioneered over the last decade or so. (Yulex is the name of the company Patagonia works with to make it.) Various other brands have begun using the technology too. There’s still some synthetic content incorporated into the mix, but 85% of the rubber foam is natural.
Importantly, the rubber is tapped from rubber trees grown in plantations certified by the Forest Stewardship Council and the Rainforest Alliance. A single tree in one of these plantations produces approximately enough rubber for one wetsuit every day.
Some surfers used to say this natural rubber was a bit stiffer than neoprene. These days, thanks to gradual improvements in the formula, you can barely tell the difference. Whether or not the market can be convinced, and whether the FSC-certified model can be upscaled to satisfy global wetsuit demand, remains to be seen.
So, there’s the neoprene foam (or natural rubber foam), and then the fabric either side of it. When you hear talk about recycled wetsuits, they’re generally talking about the jersey fabric, which is only a small percentage of the suit’s material.
The neoprene foam accounts for the majority of a neoprene wetsuit, and it’s also the material with the largest environmental footprint. At present, it can’t be made from fully recycled materials. Many wetsuit manufactures now incorporate scrap rubber tyres into the neoprene mix – this is the aforementioned “carbon black”. Even then, the neoprene will have a maximum recycled content of around 30%.