Rayon is a semi-synthetic fiber that’s used in a wide variety of clothing and other textiles like bedsheets. Since the raw material is sourced from plants (such as beech trees or bamboo), rayon is often advertised as “eco-friendly” or “sustainable.”

But is it really? We’re going to take a closer look at this popular fabric to find out what the real deal is.

What is Rayon Fabric?

Rayon seems to have gained more popularity in recent years, but it’s actually been around for quite a while (over 150 years). When it comes to performance, rayon is a great fabric: it has a flowy drape, it is breathable but strong, it’s moisture absorbent, and it’s smooth and silky.

Rayon is a semi-synthetic fabric. That means it’s sourced from natural resources but then processed with synthetic chemicals in order to create the final product. According to the Federal Trade Commission’s definition, “semi-synthetic” means there isn’t actually any of the raw material left in the final product. In other words: it’s not all-natural.

The problem with rayon is that it’s a really confusing fabric for customers. Brands will advertise it using phrases like: “It’s made from bamboo! It’s plant-based!” Consumers hear this and think, “Sounds great!” and hand over their money.

But the truth is: whether or not rayon is actually non-toxic and/or eco-friendly greatly depends on how it’s sourced and manufactured.

But before we get into the nitty-gritty of rayon toxicity, let’s talk a bit more about the basics.

What is a ‘Cellulose Fiber’?

Rayon is considered a cellulose fabric. What does that mean?

Basically, cellulose = sourced from plants.

Cellulose is an umbrella for any fibers or fabrics that are made out of plants. This includes cotton, linen, hemp, and rayon.

Rayon’s Versatility & Performance

It’s no wonder rayon is such a popular fabric. Compared to other fibers, rayon is a versatile fabric that can be used for everything from athletic wear and bedsheets to sundresses and lingerie.

One of the downsides to rayon, however, is that it can be negatively affected by too much heat, light, and/or moisture. For this reason, some rayon fabrics are best dry cleaned.

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The Types of Rayon Fabric

There are actually a few different types of rayon: viscose, modal, lyocell, and cupro. Let’s do a quick rundown on the differences between these types of rayon.

Viscose Rayon

The terms “viscose” and “rayon” are often used interchangeably. Sometimes you may see “rayon” listed on a garment tag, and other times you may see “viscose.”

Viscose rayon is most often called artificial silk because it has a smooth, luxurious feel that’s similar to real silk. You can think of viscose like “general” rayon. It can be made from wood pulp (which may come from several different types of trees) and/or bamboo.

Modal

Modal is a specific type of rayon that’s made from pulp sourced from beech trees. It’s more expensive but it’s strong and luxurious, so it will often be blended with fabrics like cotton or spandex to make stronger fabrics.

Lyocell

Lyocell is also made from beech trees, but it goes through a different process than modal does. Its manufacturing process requires less harsh chemicals, making it safer and more environmentally friendly. Of all three types of rayon, the feel of Lyocell is the most similar to cotton or linen (which is why you’ll often find it blended with those fabrics). Lyocell is also the most absorbent of all types of rayon.

Cupro

Cupro rayon (sometimes labeled as “cupra rayon”) is made with recycled cotton and/or cotton industry byproducts. They use cotton as the raw material (instead of trees or bamboo), but then process using similar chemicals to create the final cupro rayon fabric. (We’ll talk more about what those chemicals actually are in a minute.)

how is bamboo fabric made

Bamboo

Bamboo fabric can be a sneaky one. In the same way that beech trees can be made into modal or lyocell, bamboo can be made into rayon/viscose fabric as well. Like other types of rayon, bamboo fabric is strong and durable but is also stretchy and SUPER soft to the touch. That’s why so many brands use it for things like bedding and underwear.

“100% Bamboo” Fabric is a Big RED FLAG

Back in the 1990s and early 2000s, a lot of big brands were labeling their clothing and bedding as “100% bamboo”… and they got in trouble for it.

In 2015, the Federal Trade Commission (FTC) fined four big retailers—Nordstrom, J.C. Penney, Bed Bath & Beyond, and Backcountry—for mislabeling rayon textiles as “bamboo” under the Textile Products Identification Act. They aren’t alone either; other huge retailers like Amazon, Macy’s, Kmart and Sears have all paid fines for mislabeling their rayon products.

By law, fabrics that are made of rayon are required to be labeled as rayon or viscose (even if the fabric is originally sourced from bamboo). So if you ever see a label that just says “100% bamboo” as opposed to something like “viscose from bamboo”, this should be a big red flag for you. It means the brand is not being as transparent as it should be. Not only is it greenwashing, but it’s also illegal.

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How is Rayon Made?

To turn something as hard and rough as wood into soft and silky fabric, there is a relatively complex manufacturing process involved. Here’s how it happens:

  1. Wood is dissolved into a pulp with caustic soda (also known as sodium hydroxide), converting it to what’s called alkali cellulose.
  2. The alkali cellulose is then treated with carbon disulfide to make cellulose xanthate.
  3. The cellulose xanthateis then pushed through a device called a spinneret to make the pulp solution into filaments that can be made into actual fibers.
  4. Then, those filaments are put into a sulfuric acid bath in order to solidify them into fibers.
  5. Those fibers are then spun into fabric.

The question we have is: what’s the deal with all of those chemicals used in that process? Are they safe or toxic? Are any of the chemical residues left on the end products?

A Closer Look at the Toxic Chemicals Involved in Making Rayon Fabric

Let’s go through the above chemicals individually to talk about how safe (or not so safe) they are:

Carbon Disulfide: This is the worst chemical used in the rayon-making process. This substance “can cause dizziness, poor sleep, headache, anxiety, anorexia, weight loss, and vision changes. It can harm the eyes, kidneys, blood, heart, liver, nerves, and skin.” It can also lead to coronary heart disease, psychiatric symptoms like hallucinations and paranoia, retinal angiopathy, psychophysiological effects, central nervous system (CNS) effects, infertility, menstrual disorders, and more.

Sodium Hydroxide: According to the CDC, “Sodium hydroxide is very corrosive. It can cause irritation to the eyes, skin, and mucous membrane; an allergic reaction; eye and skin burns; and temporary loss of hair.”

Sulfuric Acid: Sulfuric acid is a “corrosive substance, destructive to the skin, eyes, teeth, and lungs. Severe exposure can result in death.” Additionally, “Evidence suggests that occupational exposure to sulphuric acid mists in combination with other acid mists can be carcinogenic.”

In his 2016 book, Fake Silk: The Lethal History of Viscose Rayon, Paul David Blanc wrote about how you can’t even buy rayon that’s made in the U.S. anymore because the manufacturing process is so toxic that it can’t pass the EPA’s regulations.

He also wrote about the severe negative effects these chemicals had on rayon factory workers. He writes: “viscose rayon manufacturing was inextricably linked to widespread, severe and often lethal illness among those employed in making it.” For these workers, severe health concerns like nerve damage, heart disease, stroke, and even “insanity” were not unusual.

Not only that, but during and after those chemicals are used for manufacturing, they leak into the air and are dumped into waterways, poisoning not just workers but entire surrounding communities.

This in-depth report by Changing Markets Foundation looks at the rayon industries in China, Indonesia, and India, how these chemicals are causing water and air pollution, and the severe negative health consequences that this pollution has on workers, citizens, and wildlife. (If you want to dive deeper into the problems with rayon, definitely check out the report—it’s very good! And here is the updated one.)

It’s worth noting that it’s not just a few factories that are causing this toxic pollution either—it’s most of them. These are very large rayon production companies that produce fabric for huge brands like H&M, Zara, ASOS, and many more. We’re not just talking about a few bad actors; we’re talking about almost an entire industry.

Are There Chemical Residues Left on Rayon Fabrics?

So we know that rayon production is toxic for the workers, citizens, and environment where it’s produced, and for that reason alone, it’s worth avoiding.

But that still doesn’t answer our question about whether or not it’s toxic for the end consumer. By the time a rayon shirt gets to you, does it still contain toxic chemicals?

Unfortunately, we just don’t know for sure. There is little information available on just how much of this chemical residue is still on or infused in the fabric by the time it gets to you. The Changing Worlds report states that “These chemicals do not necessarily remain as residues on the final product.” While that’s somewhat comforting, we’d like a bit more testing and confirmation here.

In the meantime, make sure you buy bamboo fabrics that are certified by OEKO-TEX. This label means they’ve been certified by a third party that the end-product doesn’t contain toxic substances. Although OEKO-TEX is not the end-all/be-all certification (since it doesn’t take into consideration the entire life of the product), it’s most definitely better than nothing.

Rayon & Deforestation

In addition to it being incredibly toxic, rayon has been linked to serious deforestation. An estimated 30 percent of the wood pulp used to make rayon is even sourced from ancient and endangered forests.

The only good news here is that (thanks in large part to the work of Canopy) many large brands have committed to sourcing their rayon from sustainably managed forests.

Is Rayon Biodegradable?

There is good news on this front: rayon is in fact biodegradable. Just remember that just because a fabric CAN be biodegradable, it also depends on what is added to the final product in terms of dyes, etc. You probably don’t want to just throw your old rayon shirt into your backyard compost unless you’ve talked to the brand about all of the chemicals they’ve used and they have been very transparent with you.

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Image: Valani (which uses TENCEL and hemp fabrics)

A Better Type of Rayon

If you’re going to buy rayon fabrics, it’s best to purchase TENCEL. TENCEL is made by a company called Lenzing. Lenzing makes lyocell (made from eucalyptus trees) and modal (made from beech trees) in a less toxic and more sustainable way. It uses sustainably harvested wood pulp and a “solvent-spinning process [that] recycles process water and reuses the solvent at a recovery rate of more than 99%.” This closed-loop manufacturing process means that all of the chemicals used remain inside the production cycle and aren’t getting dumped into waterways or the atmosphere.

TENCEL uses N-Methylmorpholine N-Oxide (NMMO). Although N-Methylmorpholine N-Oxide is much less toxic than the chemicals used in alternative types of rayon, it’s still classified as an irritant. Here we have the same issue of not really knowing whether or not (or how much) of that chemical ends up in the end product. But although it may not be perfect, TENCEL is a much better option for rayon fabric.

TENCEL also sourced its wood pulp from FSC-certified, sustainably managed forests.

Although TENCEL is the most popular and widely used, there are a few other brands that also produce rayon in a more responsible way. Birla Excel, for example, is another rayon fabric that uses a similar process that TENCEL does.

Can Rayon Be Organic?

Most of the time, you won’t see general rayon, lyocell, or modal advertised as organic, but that’s not the case when it comes to bamboo. It’s not uncommon to see brands advertise their bamboo fabric as organic. But there are a few issues here.

Bamboo Fabric Cannot Be Certified Organic

The Global Organic Textile Standard (or GOTS, which certifies things like organic cotton) will not certify bamboo rayon because the actual end fabric is not a natural material (and therefore cannot be organic).

The USDA doesn’t certify organic bamboo because almost all bamboo grows in and is sourced from China.

The Forest Stewardship Council (FSC) DOES verify sustainably sourced bamboo products, but this is not necessarily the same thing as organic. The FSC mainly looks at whether or not harvesting methods contribute to deforestation and are environmentally sustainable in the long run. They don’t pay as much attention to the chemicals used (or not used) to grow and manufacture the products.

To add even more confusion, in 2018, 22 FSC-certified bamboo manufacturers were caught committing fraud. Even though the FSC thoroughly investigated this and stripped the manufacturers of their certifications immediately, it does cause consumers to question the true sustainability of their FSC-certified bamboo.

So, if bamboo cannot be certified organic, then why do brands advertise their bamboo as organic?

Well, just because a third-party organic certification isn’t available doesn’t mean bamboo can’t be grown in an organic manner (meaning without harmful herbicides, pesticides, and synthetic fertilizers). Essentially, it just comes down to whether or not you trust the brand. Do you trust that they have been extremely thorough in vetting every single step of their supply chain, that they are regularly auditing their growers and suppliers, and that they are being completely transparent with their customers along the way?

The truth is that bamboo can be a much more sustainable fiber compared to other plants like trees and cotton. It grows very fast, it doesn’t have to be replanted, it requires much less water to grow, and it can easily grow without the use of things like pesticides.

So, when you’re looking at bamboo rayon/viscose fabric, don’t be afraid to ask the brand more questions. Also look for other types of certifications such as ECOCERT (which considers environmental sustainability factors), OEKO-TEX (which looks at toxic chemicals present in the end product), ISO 14001 (which verifies the environmental sustainability of a factory), and Fair Trade and/or SA 8000 (which indicate safety for workers).

Boody and Cariloha are good examples of bamboo brands that carry a lot of third-party certifications, used closed-loop production processes, and prioritize transparency for their customers. (They also don’t advertise their products as “organic” which is a good sign that they’re not trying to greenwash you.)

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Image: Boody

What About Other Types of Bamboo Products?

There are a LOT of bamboo products out there—from toothbrushes to toilet paper. So what’s the deal with these products; are they just as bad as rayon fabric?

Well, it ultimately comes down to the amount of processing involved. Something like a bamboo toothbrush or cutting board is much closer to the form of bamboo as it naturally grows, and therefore doesn’t require as much (if any) chemical processing.

When it comes to bamboo paper products (like toilet paper, paper towels, paper plates, etc.), we reached out to a few companies that manufacture bamboo paper towels and toilet paper to get some more info. They confirmed that no sodium hydroxide, carbon disulfide, or sulfuric acid is used to make their products. (It should be noted that we reached out to more conscious brands like the ones on this list that prioritize eco-friendly, safe practices as well as transparency with customers. We’re not sure the same can be said of conventional paper companies.)

The Healthiest Fabrics (For Humans & Our Planet)

At the end of the day, it’s probably best to skip most rayon. If you are going to purchase lyocell or modal fabric, make sure it’s from TENCEL or another brand that’s producing more responsibly. For bamboo, make sure it comes from a very transparent and certified brand like Boody.

For healthier and safer fabrics, choose from the following:

  • Organic Cotton
  • Hemp
  • Linen
  • Silk (regular silk is a natural fabric, but peace silk is a more ethical alternative because it causes less harm to the silkworms)
  • Wool (Cashmere, Merino, Tweed)

Skip the synthetics like polyester and nylon whenever you can.

What about Recycled Fabrics?

Recycled fabrics are usually better than virgin fabrics because they require a lot fewer resources to produce and increase the circularity of materials on the whole.

Fabrics that are made from recycled plastics (such as ECONYL) are a better option for our environment because they keep plastic out of our landfills and waterways. However, if you’re really sensitive and/or are trying to cut out as many potentially toxic chemicals as you can, you might want to skip even the recycled synthetics. These can contain small amounts of toxic chemicals like BPA and other endocrine disruptors, which can then be absorbed through your skin when you wear them.

Conclusion

The question of whether or not rayon is actually sustainable and non-toxic is a very confusing one, which is really frustrating for consumers. We hope this article has at least helped to clear some things up for you… but we also hope to see even greater transparency from the rayon/viscose/bamboo industry moving forward.


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Image credits: Ron Lach, Sam Lion, Martin Péchy, Pixabay