Short answer: it isn’t. Or maybe. Or it depends.
Fashion is often blamed for being the world’s fourth biggest polluter1. Meanwhile, bamboo has gained a lot of popularity over the past years in the fashion industry, and for valid reasons.
Bamboo is the fastest growing plant on earth, doesn’t need any pesticide or other chemicals to thrive healthily and requires only rain water to grow. So we can certainly say that bamboo is very sustainable. But we’re not wearing stalks of bamboo, are we? What we are actually wearing is bamboo fibre and might not be as glorious.
The Good, the Bad and the Viscose
It is the transformation from plain bamboo to bamboo fibre that could move “bamboo” from one side of the sustainable competition to the other. Here are two ways to transform bamboo into bamboo fibre.
- Method 1: to crush the bamboo mechanically. The retting process uses a natural enzyme to break down the cell walls so the fibre can be extracted. This method is slow and expensive, but relatively eco-friendly. The fibre resulting from this process is often referred to as bamboo linen.
- Method 2: it’s the most common way of making it: the viscose method. The bamboo is treated with a cocktail of solvents to convert it into a thick liquid that is forced through a spinneret into a chemical bath where it solidifies into fibre.
So whether the end-fabric is sustainable or not highly depends on the processes, chemical substances and resources it took to get there. As mentioned by GOTS, almost all bamboo fibre used in industrial textile production isn’t the natural bamboo that is used but a viscose derived from bamboo. So don’t let yourself be lured, and double check the facts!
Not all bamboo is equal
Bamboo viscose is classified as Class E in Made-By Benchmark for Fibres (if you don’t want to read it, just know that Class E is roughly for the losers of the sustainable competition — it’s the very bottom of the list). The parameters taken into account to determine whether a fibre is a sustainability super-champ or a loser are green house gas emissions, eco-toxicity, human toxicity, energy input, water input and land use (yep, they haven’t gone halfway).
So if you see that something is made of “bamboo” — dig a bit deeper to assess whether you’re simply being marketed plain old viscose (also called rayon) that was surely derived from bamboo pulp but processed with heavy chemicals and produced harmful emissions.
Don’t get us wrong, conventional bamboo viscose isn’t the worst material out there — it still performs way better than silk, conventional cotton, wool and nylon for example2. What we’re pointing out here is that it should probably not be marketed as the Greenest Fibre on Earth, because it isn’t.
Images credit: Sarah Dorweiler, Yoann Boyer, Volha Flaxeco — thank you.
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