Let’s face it, waterproof overtrousers are not the world’s most exciting bit of outdoor kit. They do an important job, namely, to keep your lower half dry in the hills and mountains or out on the trail – but few people rave about how good their rain pants are.
True to form, Mountain Equipment’s Makalu trousers are typically understated. They come in one colour, black, the standard hue for most walking overtrousers. They look practical, sturdy and reliable – but not that exciting. Or are they? Because as it happens, they are made from a pretty nifty fabric. It’s standard three-layer Gore-Tex in a sturdy 75D fabric. But it also has an important USP when it comes to sustainability…
The headline here is that, just like the latest version of the Mountain Equipment Makalu waterproof shell, these trousers now use Gore-Tex’s new, more sustainable ePE fabric, along with a PFC-free durable water repellent finish that ensures reliable performance with less environmental impact. To explain this innovation, we need to get a bit science-y.
Gore-Tex is a waterproof-breathable membrane made from a very thin layer of ePTFE, or expanded polytetrafluoroethylene. This is then bonded or laminated to a face fabric, usually made of nylon or polyester, finished with a DWR (durable water-repellent) treatment to help rain bead and roll off the surface of the fabric. On the reverse of the membrane, another layer is applied to protect the membrane from abrasion and contamination. There are various different types of Gore-Tex fabrics on the market, which differ slightly in their layered constructions, but up until now all have been made from ePTFE.
This is an issue because ePTFE contains PFCs – perfluorinated compounds, sometimes called fluorocarbons. These are long-chain polymers that bio-accumulate in the environment and in organisms. In other words, they never break down, which has led to them being dubbed ‘forever chemicals’.