* Disclaimer: There is some debate over whether manufactured cellulosic fibers (MCFs) are environmentally sustainable or not. I am not here to offer an opinion on the topic, rather, my goal in writing this post is to provide you, the consumer, with the facts. If, after reading this post, you decide that you would like to continue to include MCFs in your wardrobe, that is your decision.*
This blog post has been a long time coming. Manufactured cellulosic fibers (we will call them MCFs) are a huge part of the textile industry and there is a lot to unpack. I hesitated to write this post for a few years because I wanted to make sure I got it right. In this post I will mainly discuss viscose rayon. I will touch on lyocell towards the end, but any generalized statements are referring specifically to the viscose process. The information I am using comes from the book Fake Silk: The Lethal History of Viscose Rayon by Paul Blanc, and from my education at the NC State College of Textiles. What has plagued me most about this topic is that there is so much information hidden from the consumer. If you have any questions about this topic or you would like to know my thoughts on purchasing MCFs, I am more than happy to communicate over email at firstname.lastname@example.org.
Rayon is my soap box topic. People that know me have heard what I have to say about this subject. My husband makes fun of me all the time for my apparent obsession with this subject, but I can't help it. Ever since I learned about rayon in college, I can't keep my mouth shut. Why? Because after having my eyes opened, I realized that most of the consumers in the world are being purposefully mislead by large textile companies.
If you are reading this and have no idea what rayon is, and are wondering if this applies to you, I assure you it does. I would guess that everyone owns some sort of rayon. It may be clothing, towels, or even your dish sponges and car tires. Rayon is everywhere. Why should you care? Because people that produce rayon are dying from it. You have (most likely) never heard of this because, when a consumer is not directly affected and the material in question is extremely profitable, the manufacturing process, no matter how toxic, will continue.
Now that I have your attention, let's get on with the facts. Here's what you need to know:
This post is specifically about viscose, aka rayon, modal, and (despite being in direct violation of the FTC) "bamboo" fabric. These are all manufactured cellulosic fibers. When we talk about fibers, they break down into different categories based on what they're made of. For more information on different fibers, read our post about it here. MCFs are tricky because their chemical breakdown, once they are made, is cellulose. However, they aren't a true cellulosic fiber because they are made in a manufacturing facility. For this reason they toe the line between natural and artificial, leading many companies to manipulate their marketing to make the fiber seem more natural than it really is. For comparison, true cellulosic fibers include hemp, cotton, jute, and ramie.
The general process for making MCFs is actually quite simple. The base of the fiber is cellulose, therefore, you can use any type of plant matter as a starting point. You will see different fibers marketed as "made from" bamboo, soy, and even beech trees. At the end of the day, it doesn't make a difference what plant matter is used, because cellulose is cellulose no matter what plant it comes from.
The cellulose is then treated with various chemicals - the most common process (the viscose process) uses aqueous sodium hydroxide and carbon disulfide - powerful solvents, that "melt" the cellulose into a viscous solution. This solution is then forced through a spinerette (essentially a showerhead) to form long continuous fibers. These new fibers are extruded into a bath of sulfuric acid that chemically hardens the fibers so that they hold their shape. During this reaction, the carbon disulfide escapes from the solution and goes off into the air.
The fibers are rinsed and spun, and at this point, have been returned to their cellulose make-up, only now, they are fine, soft fibers that are ready to be made into fabric. You may be surprised to find that if you replace the spinerette and instead feed the viscous mixture through a long thin slit, you end up with cellophane. Inject the mixture with air, and you have a sponge. All of these products are safe for human use, and free from any dangerous chemicals by the time they reach the consumer.
Image from Textile Learner
The two main issues that I have with MCFs are the toxic manufacturing process, and the way MCFs are marketed to the public.
The main solvent used in the viscose process, carbon disulfide, has a long history of toxicity. In the Victorian era, carbon disulfide was being used in the production of rubber goods until scientists realized it was incredibly toxic. In lab studies conducted by scientist Dr. John Snow (for any fans of BBC's Victoria, you may remember him as the stuttering doctor who attributed a drinking well to the cholera outbreak in season 3), mice exposed to carbon disulfide "after running about for a minute, fell down and stretched [themselves] out violently and died". Dr snow goes on to say, "Indeed, I feel convinced that, if a person were to draw a deep inspiration of air saturated with [carbon disulfide] vapour at a summer temperature, instant death would be the result".
Why then, would this chemical continue to be used in the production of anything at all? Well, curiously, throughout history there are repeated periods of "rediscovering" the toxic effects of carbon disulfide after having conveniently "forgotten" about them. Meanwhile, during these stretches of ignorance, large companies were getting rich from the production of viscose and cellophane.
There used to be viscose plants all over the US and in Europe during the turn of the 20th century. There was even a viscose plant in the town I live in, Roanoke, VA, dumping toxic chemical waste into the Roanoke river. Traditionally, these older factories had bars on their windows to prevent viscose workers from jumping to their deaths because one of the effects of carbon disulfide poisoning is insanity. Other notable side effects of carbon disulfide poisoning include sexual impairment, and damage to the nervous system causing blindness, heart disease, stroke, Parkinsons, and cognitive impairment.
I could go on, however, this is the bottom line: viscose production has a long history of carbon disulfide poisoning that has killed, and is continuing to kill thousands of people and shortening and impairing the lives of countless others.
Why did this continue? Primarily because legal battles between individuals and large manufacturing companies surprisingly had no effect on the industry. Secondly, because we have moved our production of viscose to developing countries where their workplace regulations are not as strong. Most of the leading viscose manufacturers are based in China, India, Thailand and Indonesia and we have no data on the health of the workers there.
Since cellulose is involved in the manufacturing process, viscose rayon is often marketed as eco-friendly. Any company claiming to sell textile products made from "bamboo", "soy", "beech trees" etc., are really just selling you rayon, and at the expense of the health and lives of viscose manufacturers.
Many large companies, including Bed Bath & Beyond and J.C. Penny, have been sued for claiming to sell "bamboo fabric", however many smaller companies are never called out. Look at this info-graphic from a manufacturer of "bamboo" baby towels explaining their fabric:
This image makes this look like a very environmentally friendly option. However, because this company does not disclose where their bamboo fabric comes from, it is very likely NOT from Lenzing, the only known rayon manufacturer with the appropriate safety regulations in place. Furthermore, on their website they claim that their "rayon from bamboo" fabric is broken down with a "natural enzyme" - this is, very likely, a lie. If this existed, it would be a huge turning point in textile production. I find it hard to believe that this small company has made this advancement and no one knows. I reached out to them about this and haven't gotten an answer.
A word on Tencel and Lenzing:
There is a company, Lenzing, in Austria that is one of the leading manufacturers of "environmentally friendly" MCFs and is the owner of the Tencel brand. Lenzing used to to be a solely a viscose plant that was actually part of a concentration camp during WWII. While they have done their part to try to clean up their act, they are still using toxic chemicals to melt various types of plant matter into a sludge. How do they avoid carbon disulfide poisoning? Well, for the fibers that they create using this chemical, they have a money saving process that allows them to recapture the carbon disulfide instead of releasing it into the air. This collected chemical can then be re-used in the next batch of viscose. There are lots of fancy monitors and ventilation systems in place to ensure the workers aren’t exposed to too much carbon disulfide. Also, there is a medical team that performs routine urine tests on the employees to make sure their carbon disulfide levels do not reach dangerous levels. I don't know about you, but I interpret that to mean that there is some level of carbon disulfide that is allowed to be present in the body before it is pronounced "dangerous". So far, this method has been successful in preventing significant carbon disulfide poisoning. Fake Silk author and rayon researcher Dr. Blanc went to visit Lenzing, where they "proudly claimed" that they had not had anyone jump from their tower since the 1950s.
While Lenzing still produces viscose rayon, they also have a number of other products, including Tencel. Tencel is a branded version of lyocell, a similar MCF that is made without carbon disulfide. Tencel is not a completely natural product, but the word "synthetic" is conveniently avoided in its marketing. The new solvent used to make Tencel is N-Methylmorpholine N-oxide, also known as NMMO. This chemical has a clean bill of health, however that is only it’s default status because very little research has been done on it. Research needs to be paid for, and only topics that people want to be researched, will be researched.
Why are we so keen on continuing MCF production? Because it's cheap, extremely soft, easy to dye, and customers love it.
If you would like to learn more about this, you have a few options:
- Email me! I will be more than happy to answer questions for you. There is a lot more to break down with this topic and I have only just begun to skim the surface.
- Listen to the radio interview with Dr. Blanc here.
- Read Fake Silk: the lethal history of Viscose Rayon by Paul David Blanc.
A consumer tip: if you want more information, ask for it! You have the right to know what you are buying. Email, reach out, ask questions to the companies you are buying from. Call them on their practices - it is OK!
If you have any questions about the sustainability of a product or company, feel free to email me and I will look at their website for you, and give you my opinion.
THE MOST IMPORTANT THING:
No matter what you buy, how it was made, or what it is made out of, what matters most is that you buy the item out of necessity, and that you use it. The largest problem facing the fashion industry is the sheer over-consumption by us, the consumers. If you buy less, and choose well, that is what really matters. Extending the life of your clothing is the best way to help the environment when it comes to clothing. Buy only what you need, and USE IT UP!