12 Apr

Material Guide: Is Bamboo Fabric Sustainable?

What is Bamboo Fabric?

The fast growing grass has made its mark as an eco-crop. From construction to homewares to fabrics, bamboo is having its moment in the limelight. But given that some claims associated with bamboo have been disputed, such as its sustainability, UV protection, and antibacterial properties, is it really the miracle crop many are claiming it to be? Just how sustainable is bamboo?

Growing Bamboo

It starts out looking good. Bamboo can be a very sustainable crop; a fast growing grass, it requires no fertiliser and self-regenerates from its own roots, so it doesn’t need to be replanted. When compared to cotton cultivation, which requires large amounts of water, pesticides and labour, the advantages are pretty clear.

But wait! Before you run off to restock your wardrobe, there are a few things to consider. For starters, although bamboo is fast growing and requires no pesticides, that doesn’t mean that it is being grown sustainably. The majority of bamboo is grown in China, and there is no information regarding how intensively bamboo is being harvested, or what sort of land clearing might be underway in order to make way for the bamboo. Also, although bamboo doesn’t need pesticides, there is no guarantee that they are not being used to maximise outputs.

Creating Fabric

Okay, you think, so bamboo might have some issues, but it still uses way less chemicals, and is more environmentally friendly than cotton, right? While this is almost certainly true for the cultivation phase, the same can’t be said about the manufacturing process. There are several ways to turn bamboo into a fabric.

The first process involves combing out the bamboo fibres and spinning these into thread. This results in a slightly coarse fabric that is usually called “bamboo linen”. Creating this “linen” is labour intensive and expensive and the result not suitable for the soft, intimate products for which bamboo is most in demand.

The second and much more popular method is the process used to make the silky soft bamboo fabric you find in sheets, underwear and more. This “bamboo rayon” is produced through a highly intensive chemical process, similar to the process used to turn wood chips into rayon. This is where the sustainability of bamboo gets a little prickly. Rayon is essentially a raw material converted through a chemical process. The end product of this process ultimately falls into a category that is somewhere between naturals and synthetics. The source of the cellulose can be cotton, wood, and yep, bamboo. So essentially soft bamboo fabric is actually processed in the same fashion as semi-natural rayon.

Bamboo rayon is most commonly made through what is known as the viscose process, which involves dissolving cellulose material such as bamboo in a chemical solution to produce a pulpy viscous substance. This is then pushed through a spinneret, and “spun” into the fibres that can then be made into threads and fabrics.  The chemicals used in this process are highly toxic and a risk to human health. About 50% of hazardous waste from rayon production (including the bamboo variety) cannot be recaptured and reused and goes directly into the environment.

Not quite the ecological delight we dream of!

As a side note, there is no conclusive evidence that many of the claimed qualities of bamboo, such as it antibacterial properties or UV resistance, are still present in the fibre after it has been put through such an intensive process.

Finally the good news: a similar fabric called lyocell (also known by the brand name TENCEL®) uses a closed-loop process to recapture and reuse 99% of the chemical solution. Tencel is often made from sustainably farmed eucalyptus trees, and the fabric was awarded the “European Award for the Environment” by the European Union. The lyocell process can also be used to create fabric from bamboo, although few brands are doing this.

So what does all this mean?

Bamboo itself can be a highly sustainable crop, if grown under the right conditions (and it often is). However, most bamboo fabrics on the market are a form of rayon where the manufacturing process is highly intensive and involves many harmful chemicals.

While lyocell is a more sustainable alternative with much less impact, but it’s harder to find lycocell products made from bamboo. For some types of clothing look for ecofriendly fabrics like organically grown hemp. In most cases organic cotton will be a better choice from the point of view of the environment, all other things being equal (especially the fabric dying process).

We should know that the majority of products labelled as “bamboo” are actually rayon, involve intensive chemical emissions and likely without the same beneficial properties as the unprocessed bamboo plant. Bamboo fabric is much less costly to produce than cotton (and avoids the extensive use of pesticides in non-organic cotton production), and production is not as chemically intensive as polyester, but bamboo fabric is sadly not the perfect answer to all our ethical clothing conundrums; in fact European NGO Made-by rates bamboo viscose on a par with conventional cotton at the bottom of its A to E rating scale. As the LA Times has said, bamboo “has largely been discredited as an [eco friendly] alternative source.”

Bamboo has advantages over cotton when it comes to it’s sustainable farming potential. But there’s a lot of work done to develop and make widely available cost-effective and environmentally sustainable ways of creating the soft and silky bamboo fabrics that we’re dreaming of.

Editor's note: Feature image via Unsplash.

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