Sustainable Outdoor Clothing ?!?! continued

….for the back story, check out Sustainable Outdoor Clothing ?!?!…

2) Clothes that keep me warm

When it comes to base- and mid-layers, I am for natural materials. Of course, there are functional tech-fibres that feature a range of desirable properties: fast drying, light, warm, wicking moisture away from the skin, odour-killing….but they are synthetic, mostly derived from fossil fuels and become a waste management problem when they are discarded.

Take synthetic fibres impregnated with anti-microbial silver: the rationale is that bacteria, fungi and algae cause stains and odours, and if clothing is impregnated against these, it doesn’t smell or stain. Silver is increasingly used as anti-microbial (not only in textiles, but also in food packaging and preparation areas, exterior paint, etc. ). Textiles are typically impregnated with silver chloride, silver zeolite or silver nano-particles, and all of these leach out to a greater or lesser degree during washing cycles. When silver is retained in sewage treatment works, it may end up in soils in form of sewage sludge fertiliser and some of it is transported into rivers and oceans. Silver is relatively benign to us, but is quite toxic to aquatic organisms, such as microalgae (see references), which form the base of the food chain. I have no desire to add to the metal burden of rivers and oceans and will leave silver-impregnated items in the shops… 

There are other, more general problems with synthetic fibres: resources and manufacture is based on the petrochemical industry and the already mentioned waste management.  Synthetics are incredibly slow to degrade in landfill, and only fit for incineration. On everybody’s mind since Richard Thompson (University of Plymouth) has coined the term ‘microplastic‘ and David Attenborough has narrated Blue Planet II, the release of microfibers from fleeces and other synthetic clothing during wash cycles is adding to the ‘plastic soup’ in the oceans that finds its way into the food chain and onto our plates. Not only oceans. Microfibers have been detected in food chains of wetlands, soil-based ecosystems, in bottled water and beer.  

What is the solution? Wool! More specifically, merino wool. I’m a “sensitive flower” when it comes to scratchy woollen clothing and always wore a turtleneck long-sleeved cotton t-shirt underneath woollen pullovers before I discovered merino. It’s so soft, even I can wear it directly on the skin, it’s so warm that fabrics can be so thin that they dry fast. It’s naturally odour-resistant that you don’t have to wash it every time you wear it – hang it out to air and it becomes fresh again. So, my base-, mid- and insulation layers are merino wool. It’s expensive, so I buy it in the sales. Merino is all the rage now, so not all of what’s on sale is fantastic quality (some of my t-shirts and jumpers had holes “falling” into them without me crawling through brambles), so my favourite brand is Icebreaker, the most durable pure merino I’ve got. And durable is sustainable. 

Ok, how sustainable is merino? According to O Ecotextiles, the global textile industry is one of the largest sources of greenhouse gasses on earth, requiring the energy equivalent of 132 billion tonnes of coal and 6 – 9 trillion litres of water. That’s to produce the fibres and make the yarn, to weave or knit, to dye and fashion, to transport and distribute. It includes mining materials for synthetics and using fertilisers on the fields for growing natural fibres. The energy “contained” in the production is around 63 MJ (megajoule) per Kg of wool yarn, compared to 10 MJ for flax, 55 MJ for cotton, 125 MJ for polyester and 250 MJ for nylon. Given the advantageous properties of merino wool for outdoor adventures, it has a reassuringly lower carbon footprint compared to synthetics commonly used for similar base-, mid- and insulation layers.

Ideally, organically produced wool and natural dyes would be used in processing my merino garments of choice, although I’ve not spotted that happening at Icebreaker yet. Synthetic dyes can be bad news for the environment (something I might explore in more detail some other time). So, although better than synthetics with respect to the carbon balance, durability and waste management credentials, overall, the merino clothes I buy have a long way to go to be as sustainable as they could be.

References

Foley CJ. et al. 2016. A meta-analysis of the effects of exposure to microplastics on fish and aquatic invertebrates. The Science of the Total Environment. https://doi.org/10.1016/j.scitotenv.2018.03.046

Friends of the Earth. Microfibres plastic in our clothes (and what to do about it) https://friendsoftheearth.uk/plastics/microfibres-plastic-in-our-clothes [accessed 15/02/2020]

Joyce C. 2018. Beer, Drinking Water And Fish: Tiny Plastic Is Everywhere. The Salt – What’s on Our Plate. https://www.npr.org/sections/thesalt/2018/08/20/636845604/beer-drinking-water-and-fish-tiny-plastic-is-everywhere?t=1581865864250 [accessed 16/02/2020]

Life Material Technology Limited. 2020. Antimicrobial protection information. https://life-materials.com/antimicrobial-protection/? [accessed 15/02/2020]

Lourenco et al. 2017. Plastic and other microfibers in sediments, macroinvertebrates and shorebirds from three intertidal wetlands of southern Europe and west Africa. Environmental Pollution. https://doi.org/10.1016/j.envpol.2017.07.103 [accessed 16/02/2020]

Ru Yang et al. 2017. Exposure of soil collembolans to microplastics perturbs their gut microbiota and alters their isotopic composition. Soil Biology and Geochemistry. https://doi.org/10.1016/j.soilbio.2017.10.027

The Story of Stuff. 2018. Video The Story of Stuff. By an organisation that became a movement…https://storyofstuff.org/movies/story-of-stuff/ [accessed 15/02/2020]

Urquhart J. 2014. Silver Nanoparticles in Clothing Pose No New Risk: Older antibacterial coatings, when laundered, released just as many nanoparticles into the environment. Chemistry World. Reported in Scientific American. https://www.scientificamerican.com/article/silver-nanoparticles-in-clothing-pose-no-new-risk/ [accessed 12/02/2020]

Yang Yue et al. 2017. Interaction of silver nanoparticles with algae and fish cells: a side by side comparison. Journal of Nanobiotechnology. https://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-017-0254-9 [accessed 12/02/2020]