What is rayon?
Rayon is the all-purpose name for fiber made from wood that has been dissolved and re-formed. Viscose is the most common kind, so rayon and viscose mean the same material. It starts as wood, which gets dissolved into mush using strong chemicals, including one called carbon disulfide, then squeezed back out into thread.
The name rayon was coined by the US textile trade in the 1920s to replace the older sales pitch artificial silk. The Federal Trade Commission later fixed it as a generic legal term, and in 2003 it split lyocell off into its own generic name. So a closed-loop TENCEL is now a legally separate fiber from plain rayon, even though shoppers still lump them together.
How rayon is made
Rayon is a category defined by regulation, not a single formula. Under the FTC's fiber-labeling rules (16 CFR Part 303), it is the generic name for any fiber regenerated from dissolved plant cellulose: pulp is dissolved into a liquid, forced through a spinneret full of tiny holes, then hardened back into thread in an acid bath. Plain viscose rayon is the version you meet most, dissolved using carbon disulfide, a solvent that is a serious hazard to the people who work with it.
The category is wide enough to hide real differences. Modal and lyocell are regenerated cellulose too, so they can wear the rayon name on a technicality, but lyocell is made in a closed loop with a non-toxic solvent and modal runs a gentler bath. When a tag reads rayon with nothing after it, read it as the plain, open-loop, carbon-disulfide version, the one still tied to factory-worker harm and mill pollution.
The finished, washed thread is close to inert. It is plant cellulose, chemically nearer cotton than plastic, and most of the carbon disulfide is long gone by the time the fabric reaches a hanger. Almost anything your skin reacts to was brushed on after spinning: the dye bath and any wrinkle- or shrink-resistant finish.
Not all rayon is the same
Rayon spans a real range, set by which process made it and how it was finished. Generic, unlabeled rayon is almost always the open-loop viscose version. A named process, modal, a closed-loop lyocell like TENCEL, or a certified lower-impact viscose like LENZING™ ECOVERO™, starts from the same cellulose but is made under far tighter chemical control.
Is rayon safe to wear?
Dermatologists do not flag finished rayon as toxic to touch. It is regenerated plant cellulose, and raw cellulose fibers are a rare cause of allergic skin reactions on their own. The documented danger from carbon disulfide, nerve and heart damage from daily inhalation, belongs to the workers who dissolve the pulp, not to you in the finished shirt.
Your skin reacts to what was added, not the fiber. Two culprits do most of the work: formaldehyde-based wrinkle- and shrink-resistant resins, applied to rayon and cotton since the 1920s, which Reich and Warshaw documented as an under-recognized cause of chronic clothing dermatitis at the spots where a garment fits snug; and azo dyes, some of which can release aromatic amines the EU restricts under REACH. A rash from rayon traces back to a finish or a dye far more often than to the cellulose. Cheap, uncertified pieces carry more of that residue than one with an OEKO-TEX Standard 100 label, which tests the finished garment and caps what is allowed to remain.
- Breathes and absorbs moisture As a plant-cellulose fiber, rayon lets air through and pulls moisture off skin instead of trapping it the way polyester does.
- Soft, silk-like drape Its smooth, rounded fiber gives rayon a fluid hand, part of why it was invented as a low-cost silk substitute.
- No plastic against skin Rayon carries no petrochemical polymer, so it skips the static cling and synthetic feel of a fully synthetic fabric.
Rayon defaults to 64, in the wear with care band (40 to 67), because an unlabeled rayon tag is assumed to be plain, open-loop viscose, and its dye and finish are invisible from the label alone. Ask for a named, closed-loop process like TENCEL Lyocell, or an OEKO-TEX Standard 100 piece, and the same cellulose can climb into the safest band. See the full method.
Doing this check on every product page yourself is the tedious part. The Toxome Chrome extension reads the composition for you while you shop, so you see whether something is rayon (and what else is in it) before you buy, not after it arrives.
How rayon affects the planet
Rayon is not one production standard. It is thousands of mills running the same chemistry at very different levels of control, which is why its water use spans from a few hundred litres per kilo to several thousand, and its carbon from about 2 to 11.
The fiber itself is cellulose, so it biodegrades and sheds no plastic. The damage sits in production, in the solvent and the wastewater, not in the finished cloth against your skin.
Huge mill-to-mill range. Rayon is not one production standard.
Varies widely by region and method.
Cellulose-based, though finishes and sealed landfills slow it.
Cellulosic, not plastic.
Environmental figures are separate from the health score above, which reflects wearer health only. Numbers are per kilogram of finished fiber and rounded; see sources.
Who makes rayon
Carbon disulfide, the core solvent, poisons the people who spin rayon. It is linked to nerve, psychiatric, and cardiovascular damage, and it is one of the longest-documented occupational harms in the whole textile industry.
Changing Markets' Dirty Fashion investigations documented untreated viscose wastewater contaminating rivers and drinking water, and roughly a third of viscose has historically been traced back to endangered forests. Some producers are improving, but the floor is low.
How to care for rayon
shop LENZING™ ECOVERO™ & TENCEL lyocell instead
Rayon (Viscose), answered
The finished fiber is not considered toxic to touch. It is regenerated plant cellulose, chemically closer to cotton than to plastic, and raw cellulose rarely triggers a skin reaction on its own. The documented harm from carbon disulfide, the solvent used to dissolve the wood pulp, falls on factory workers during manufacturing, not on you wearing the garment.
It can, but the trigger is almost always what was added, not the cellulose. A formaldehyde-based wrinkle finish or a leftover azo dye causes far more rayon rashes than the fiber does. Washing a new garment before wearing removes some residue, and an OEKO-TEX Standard 100 label caps how much finish and dye can remain.
It is a hybrid the FTC calls regenerated: it starts as a natural plant, wood or bamboo cellulose, then is dissolved in chemicals and re-formed into thread. So it is neither a fully natural fiber like linen nor a petrochemical plastic like polyester. On a US tag it has to be named rayon or viscose, never bamboo alone.
Mostly. Viscose is the most common kind of rayon, and on a US fiber-content tag the two words are interchangeable. The catch is that rayon also covers modal and lyocell, which are made under cleaner chemistry, so the same word can hide a real difference in how the fiber was produced.
No. Those phrases mean nothing on their own. All viscose starts as a plant, so plant-based describes every version of it, including the open-loop, carbon-disulfide kind. It only signals a lower-impact process if the label spells out a named one, LENZING ECOVERO for certified lower-impact viscose, or a closed-loop lyocell like TENCEL. Some brands sell both side by side, so read the exact fiber name on the composition tag instead of the marketing copy.
- HEALTH EFFECTS - Toxicological Profile for Carbon Disulfide · NCBI Bookshelf (ATSDR)
- Exposure to carbon disulphide and ischaemic heart disease in a viscose rayon factory · PMC (Br J Ind Med)
- Cardiovascular effects in viscose rayon workers exposed to carbon disulfide · PubMed
- Rayon Allergy: Identifying Symptoms and Effective Treatments · Wyndly
- Dirty Fashion: how pollution in the global textiles supply chain is making viscose toxic · Changing Markets Foundation
- FTC Warns 78 Retailers to Stop Advertising Rayon as Bamboo · U.S. Federal Trade Commission
- CanopyStyle and endangered forests in viscose · Canopy
The health score reflects wearer health only and mirrors the Toxome app. This guide is educational and is not medical advice.