Is viscose sustainable?

It depends on how it's made. Standard viscose uses an open-loop process with toxic chemicals and is linked to deforestation. But options like Lenzing EcoVero viscose and lyocell/Tencel use certified wood and closed-loop manufacturing, which are significantly better. Always look for certifications like FSC or Canopy-approved sourcing.

Is viscose better than polyester?

In some ways, yes. Viscose is biodegradable and doesn't shed microplastics when washed, which gives it a meaningful advantage over polyester. However, conventional viscose production uses toxic chemicals and contributes to deforestation. Polyester has a lower water footprint. Neither is perfect -- if you want to do better, look for lyocell/Tencel or certified organic natural fibres.

Yes. Viscose is notorious for shrinking when washed, especially in warm water. It also weakens when wet, which is why many viscose garments recommend dry cleaning or cold hand-washing. If you machine-wash viscose on a regular cycle, expect it to come out smaller and possibly misshapen. Always check the care label.

What Is Viscose? The Fabric That Sounds Natural But Isn't Quite

You see "viscose" on a clothing label and think: that sounds fancy and probably natural. It comes from wood, right? Trees are natural. Case closed.

Not so fast. Viscose fabric is one of the most misunderstood materials in your wardrobe. It sits in an awkward middle ground between cotton and polyester, and the fashion industry is more than happy to let you stay confused about it. Let's fix that.

Viscose Starts as Wood. Then Chemistry Happens.

Here's the short version of how viscose is made: you take wood pulp (usually from beech, eucalyptus, or pine trees), dissolve it in carbon disulfide -- a toxic chemical -- and force the resulting goo through tiny holes to regenerate it as fibre. That fibre becomes the silky, drapey fabric we call viscose. Also known as rayon in some parts of the world.

The long version involves sodium hydroxide baths, ageing rooms, sulphuric acid, and enough industrial wastewater to make an environmental scientist cry. The process was invented in the 1890s, and honestly, it hasn't changed that much since.

So yes, viscose starts as something natural. But by the time it reaches your blouse, it has been chemically transformed beyond recognition. The cellulose is natural. The process is decidedly not.

Is Viscose Natural or Synthetic?

Neither. And both. Welcome to the maddening world of textile classification.

Viscose is officially classified as a semi-synthetic fibre. It's made from a natural raw material (wood cellulose) using a synthetic, chemical-intensive process. This distinction actually matters, because it means:

Viscose is not a natural fibre like cotton, linen, or wool
Viscose is not a petroleum-based synthetic like polyester
It is biodegradable (eventually), unlike polyester
It does not shed microplastics in the wash

Brands love calling viscose "plant-based" or "derived from nature." Technically true. Functionally misleading. A chocolate bar is derived from cacao beans, but nobody calls a Snickers "natural."

The rule of thumb: viscose is better than polyester for microplastic pollution, but worse than cotton or linen for chemical processing. It's a middle-of-the-road fabric that can range from "not bad" to "pretty terrible" depending on how it's made.

The Deforestation Problem

Here's where things get genuinely alarming. The fashion industry's appetite for viscose requires an enormous amount of wood. How much? Around 150 million trees are felled every year to make cellulosic fibres like viscose, modal, and lyocell. That number is projected to double by 2034.

And these aren't always trees from well-managed plantations. Investigations by organisations like Canopy have found viscose linked to logging in:

Indonesia's tropical rainforests -- home to orangutans and Sumatran tigers
Canada's boreal forests -- ancient, carbon-dense, irreplaceable
The Amazon basin -- yes, really

The wood gets chipped, shipped to a viscose mill (often in China or India), dissolved in chemicals, and turned into cheap fabric for fast fashion. The final garment might cost you twelve quid. The forest doesn't grow back on that timeline.

This doesn't mean all viscose is deforestation-linked. But unless the brand tells you where their cellulose comes from, you have no way of knowing. And most brands don't tell you.

Viscose vs Lyocell vs Modal vs Tencel

If you've ever been confused by all the cellulosic fabric names, you're not alone. They all start from wood pulp, but the manufacturing process -- and its environmental impact -- varies wildly.

Fabric	Process	Chemical Recovery	Environmental Impact
Viscose (Rayon)	Open-loop: carbon disulfide dissolves cellulose	~50% chemicals recovered	High: toxic emissions, heavy water use
Modal	Modified viscose process, often from beech wood	~60% chemicals recovered	Medium: still chemical-heavy, better than standard viscose
Lyocell	Closed-loop: non-toxic NMMO solvent dissolves cellulose	~99% solvent recovered and reused	Low: minimal waste, no toxic byproducts
Tencel	Lenzing's branded lyocell (and modal). Same closed-loop process	~99% solvent recovered	Low: FSC-certified wood, audited supply chain

The takeaway: "closed-loop" means the chemicals are captured and reused instead of dumped into waterways. Lyocell and Tencel do this. Standard viscose does not. They're made from the same raw material but the gap in environmental performance is enormous.

If you see "Tencel" on a label, that's usually a good sign. If you see just "viscose" with no further detail, assume it's the conventional, open-loop kind.

When Viscose Is Fine (and When It's Not)

Viscose isn't inherently terrible. Context matters. Here's when you can feel reasonably okay about it:

FSC-certified wood sourcing -- means the cellulose didn't come from ancient forests
Lenzing EcoVero -- Lenzing's more sustainable viscose, uses certified wood and generates up to 50% fewer emissions
Canopy's Hot Button ranking -- rates viscose producers on their sourcing practices
EU Ecolabel or OEKO-TEX certification on the finished fabric

And here's when viscose is a red flag:

The brand doesn't mention where their viscose comes from (most fast fashion)
It's blended with polyester -- you get the downsides of both and the benefits of neither
It's in a disposable-priced garment clearly designed to last three wears

The best viscose is the kind attached to a transparent supply chain. The worst is the kind that shows up in a 7.99 dress with no sourcing information whatsoever.

How to Check What's in Your Clothes

Fabric composition labels are legally required on clothing, but good luck finding them when you're scrolling through 400 items on Zara at midnight. Brands bury the information. Sometimes it's three clicks deep. Sometimes the percentages don't even add up.

Fibr fixes this. Our free Chrome extension reads the fabric composition data on product pages from Zara, H&M, and Mango, and shows it as a colour-coded badge right on the product image. Green for natural fibres. Red for synthetics like polyester. Yellow for mixed.

So when a "sustainable" dress is actually 65% polyester and 35% viscose, you'll know before you hit "add to bag." No scrolling. No guessing. No marketing spin.