Good or bad bamboo?
For years bamboo has been marketed as a sustainable fabric, but these claims have recently come into question. To get to the bottom of just how sustainable a choice bamboo really is we’ve taken a closer look at the different production methods and their impact on the environment.
Contrary to what you might think bamboo is a type of grass. In fact it is possibly the fastest growing grass in the world, needing no pesticides or irrigation and taking just 4-5 years to fully mature. Harvesting bamboo is relatively easy and, after cutting, it re-sprouts thus eliminating the need for replanting. Overall the plant’s growth creates little strain on the environment and can actually help rebuild eroded soil.
However, although naturally a very sustainable crop it has become increasingly lucrative to grow, leading to mono-croping that reduces bio diversity and can lead to the need for pesticide use. Some farmers have also been known to destroy forests to create farm land to grow bamboo, damaging animal habitats such as the lemurs, mountain gorillas and pandas that depend almost entirely on bamboo for food and shelter and other food sources.
Despite this the material still compares favourably to cotton, the manufacture of which creates a much greater environmental impact due to the crops farmers reliance on water and pesticides. The sustainability of bamboo fabric is defined predominantly in the manufacturing process of which there are many different ways to convert raw bamboo fibre into a material, some sustainable and some not. Here we explain the different options and the impact on the environment.
Bamboo Rayon is a fabric made from both natural and synthetic materials and has a silky lustrous finish. The raw bamboo is converted to a fibre using an intensive chemical process involving approximately 13 different toxic chemicals.
This is another method of converting bamboo into a material, however it is also not very sustainable and uses both natural and synthetic substances. The cellulose material is dissolved in a strong chemical solvent to create a viscous liquid. The liquid is then forced through a spinneret to create a continuous filament fibre. This process is often called solution spinning but unfortunately the chemical solution the fibre is spun into is extremely toxic. Amongst many health hazards it is known to have a damaging impact on human reproductivity, and this is amplified by the fact that in most factories only 50 per cent of the chemical is recoverable.
As with linen made from flax or hemp, bamboo linen is created by crushing the plant and then combing the fibers. It is then spun and woven into a material that resembles linen. Whilst relatively simple and a more sustainable process it is highly labour intensive and thus very expensive.
Bamboo Lyocell is made via a similar process to viscose but does not use harmful chemicals. The raw fibre is combined with hydrogen peroxide and forced through a spinneret, with a hardening bath used to cool the fiber. The bath is commonly filled with a solution of water and methanol, ethanol or a similar alcohol and is therefore more sustainable. This process can also be performed as a closed-loop, meaning that 99.5% of the chemicals used during the process are captured and recycled to be used again.
Bamboo can be a good choice but it’s not as simple as it may appear. One must consider as demand for the material increases, so does its impact on the environment due to intensive farming. It would seem there’s a trade off between silky, high quality materials that are more damaging and the more sustainable linen products that are much more labour intensive and costly.
Bamboo can indeed be a sustainable material when produced responsibly but it does depend on the process used to convert it to material. Thus it’s worth asking the supplier how they are created, bearing in mind that, as a rule of thumb, the more silky lustrous bamboo fabrics will have been created using environmentally damaging chemical processes.