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? Is bamboo fabric sustainable?
Growing the 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 limited 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. However, in the last few years the Chinese government has cracked down on these more intensive processes and it is now considered extremely bad practice in the industry, which is great progress.
Creating the 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 necessarily 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 isn’t 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 source of the cellulose can be cotton, wood, and yep, bamboo.
Bamboo rayon is most commonly made through what is known as the viscose process, which involves dissolving cellulose material (in this case, 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 like caustic soda and carbon disulfide 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, but that doesn’t mean they are being dumped directly into the environment. Thankfully, wet processors in the last three years have been made to revamp their practices and there has been a great deal of improvement in chemical management and waste treatment.
The resulting bamboo viscose fabric is highly breathable, and much stretchier than cotton, making it perfect for garments that sit close to the skin like underwear and socks. It’s also easy to weave into fabrics with high thread counts to create a thin yet strong material suitable for a wide range of uses, from dresses to sheets.
As a side note, sadly there is no conclusive evidence that many of the claimed qualities of bamboo, such as its antibacterial properties or UV resistance, are still present in the fibre after it has been put through such an intensive process.
It’s worth considering a similar fabric called lyocell (also known by the brand name TENCEL® Lyocell) which 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, and this fabric is branded Monocel®, so look out for this label on clothes, though very few brands are using it at this stage. It is worth noting that while the industry is pushing for more sustainable options like Tencel and Monocel, they still only make up a small portion of the fabric available on the market, so realistically we should be continuing to work with the viscose industry to improve standard practices since the chances are it will never be replaced completely.
So is bamboo fabric sustainable or not?
Bamboo itself can be a highly sustainable crop, if grown under the right conditions. While most bamboo fabrics on the market are a form of rayon where the manufacturing process is intensive and involves harmful chemicals, recent years have seen an improvement in how these chemicals are managed, which is a step in the right direction. Bamboo fabrics are certainly a step up from polyester and conventional cotton, so as long as the brand is transparent about its origins, it can be a safe bet as a more sustainable option.
While lyocell bamboo is likely a more sustainable alternative, it’s harder to find. For some types of clothing, look for eco-friendly fabrics like organic hemp. In other cases, organic cotton or Tencel will be a better choice from the point of view of the environment, all other things being equal, especially the fabric dyeing 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. But bamboo fabric has potential—it is much less costly to produce than cotton, avoids the extensive use of pesticides in non-organic cotton production, and production is not as chemically intensive as polyester. Buying from responsible and transparent brands can also help to mitigate some of this risk.
There’s a lot of work being 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, so it’s one to keep an eye on!