Comparing breathable vs non-breathable clothing. What are good/bad points of each? [closed]

Question

What are good points and badpoints for breathable vs non-breathable clothing?

Answer 1

Aside from the practical differences aside, i.e. breathable lets sweat out, but tends to only keep rain out temporarily, breathable fabrics are typically made of 'forever chemicals' which might cause cancer, in very small doses, and stay in your body for a long time. 'forever chemicals' don't tend to break down in the environment. See for example https://www.theguardian.com/environment/2022/jan/26/water-resistant-products-toxic-pfas-study for an article about water resistant products and PFAS ("PFAS" means "Per- and polyfluoroalkyl substances").

Just in case there is any confusion about whether PFAs are needed for non-breathable fabric. It is easy to make something waterproof, without PFAs, as long as you don't require it to be breathable. Glass is waterproof, without needing PFAs, as is plastic, a sheet of rubber, a polythene bag. It is the magic of combining breathability, which obligatorily allows water to flow through somehow; with water resistance, which does not; that the magic of PFAs are required. The PFAs use water surface tension to resist the passage of liquid water, whilst allowing water vapor - a gas - to diffuse through.

There are plenty of waterproof garment materials which do not contain PFAs, and which predate the discovery of PFAs.

• Guernseys, which are made of a tight weave of waxed wool. They are heavy, itchy, not particularly warm, and not especially waterproof. Ironically, quite breathable. The fishermen around Guernsey island wear them, under the rain, and the waves.
• PU, polyurethane, waterproof materials
• PVC, polyvinyl chloride, waterproof materials Other than lacking breathability, a big downside of PU and PVC is they tend to be much heavier than the breathable versions. On the other hand, they will actually stay waterproof, rather than starting to leak water through after a bit. The downside obviously is that if it's not raining, you will get wet anyway, from your own perspiration.

As of 2022, Goretex provides membranes based on ePE which are PFA free. While this new membrane is PFA free, not all their apparel is. Goretex aims to remove many PFCs from its lines by 2025 ("PFC" means "per- and poly-fluorinated chemicals"). Toray's Dermizax is also a PFA free option, and there are brands, such as Ortovox, who, as of 2023, has an entirely PFA free line of performance shells using Dermizax. Ortovox aims to become completely PFC-free by 2024 . More information on PFCs.

It's also possible to use wash-in waxes, such as Nikwax, to waterproof one's gear. These waxes tend to be less durable than the forever chemical approaches, so one has to keep re-treating one's gear. However, Nikwax can be washed into many non water-resistant fabrics, rendering them water-resistant. Using Nikwax on army fatigues is a very convenient hack, though note that US army clothing might be already water-resistant. Other comments recommending using Nikwax on army fatigues 12 13.