Bamboo is one of the fastest-growing plants in the world, with some growing 91cm a day, which makes it a highly renewable resource - it absorbs more carbon dioxide and releases more oxygen than trees, and the root will continue to grow without the need for re-planting, all of which makes it great for the environment.
Bamboo is actually a grass, and once fully grown, some of the larger species can look like trees with a thick trunk and are much more sustainable than hardwood trees.
It’s incredibly strong, which is why it is used for making many products from flooring to furniture, skateboards to snowboards - even bulletproof vests, and reusable items such as coffee cups, straws and plates, and recently different technologies have been developed for bamboo fibre to be used for textiles, including bed sheets and blankets, and fashion items such as clothing, underwear and socks.
Clothing! But wait! Before you run off to restock your wardrobe, there are a few things to consider. Most bamboo is grown in China, and there is limited information regarding how intensively bamboo is being harvested, or what sort of land clearance might be underway in order to make way for bamboo. Also, although bamboo doesn’t need pesticides, there is no guarantee that they are not being used to maximise output.
One production process includes crushing the woody part of the plant and applying natural enzymes to create a mushy mass. The natural fibres are then mechanically combed out and spun into yarn. The result has a similar feel to linen, but very little bamboo material is produced this way since it’s labour intensive and expensive.
Most bamboo fabric is created through a chemical process very similar to the production of rayon from wood or cotton. While there are a number of ways to chemically create rayon, the most common is the viscose process, where leaves and shoots are essentially cooked in strong chemical solvents such as sodium hydroxide and carbon disulfide, both being highly toxic and risky for human health.
Once cooked, the resulting liquid is pushed through tiny holes (a spinnerette) directly into a chemical bath of sulfuric acid (dangerous again) where it hardens into fine strands.
After being washed and bleached these strands form rayon yarn which can be dyed and woven into a soft silky fabric correctly referred to as ‘rayon from bamboo’. This is lyocell, a semi-synthetic fabric that is commonly used as a substitute for cotton or silk, and a form of rayon, composed of cellulose derived from wood.
This is where the sustainability of bamboo gets a little….iffy.
Bamboo rayon is most commonly made through the latter process. About 50% of hazardous waste from rayon production cannot be recaptured and reused, but that doesn’t mean they are being dumped directly into the environment.
If not correctly managed, these chemicals pose a risk to workers’ health, with sodium hydroxide causing irritation to the skin and eyes while carbon disulfide and sulfuric acid have been linked to neural disorders and respiratory problems respectively.
Similarly, poor management of waste can cause serious damage to the surrounding environment, but thankfully, manufacturers 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 good news is that some facilities have started using more benign technologies to chemically manufacture bamboo fibres. As well as using less toxic chemicals, it can be processed in a ‘closed loop’ system whereby 99.5% of the chemicals are captured and recycled.
The lyocell process is also used to manufacture TENCEL®, a natural fibre made from wood pulp – usually from eucalyptus, beech, birch and spruce trees. You’ll have seen it used in a myriad of sustainable fashion items and in many high street brands.
The downsides are shrinkage - bamboo fabric tends to shrink at a faster rate than cotton, and the cost - bamboo fabric tends to be more expensive than either rayon or cotton.
Finally, we know that pandas love to eat bamboo, but I think there might just be enough to go round!