Short answer: yes. Acrylic fabric is plastic. It was literally invented to be a cheaper stand-in for wool, and it has succeeded spectacularly at being cheap. Everything else? Not so much.
Here's what acrylic actually is, why it's the single worst offender for microplastic pollution, and how to stop accidentally buying it.
Acrylic Is Plastic. Specifically, Polyacrylonitrile.
Acrylic fabric is made from polyacrylonitrile, a synthetic polymer derived from petroleum or natural gas. That's a fancy way of saying it starts life as fossil fuel and ends life as landfill. The fibre was developed in the 1940s by DuPont with one goal: replicate the look and feel of wool at a fraction of the cost.
The manufacturing process involves dissolving the polymer in a chemical solvent, extruding it through a spinneret (basically a showerhead for plastic), and then stretching and crimping the resulting filaments to mimic wool's natural texture. The result is a fibre that looks woolly, feels woolly-ish, and behaves nothing like wool.
Acrylic is to wool what a wax apple is to a Honeycrisp. It looks the part from a distance. That's where the comparison ends.
Unlike natural fibres that biodegrade, acrylic will sit in a landfill for 200+ years. It doesn't compost. It doesn't break down meaningfully. It just slowly fragments into smaller and smaller pieces of plastic.
Why It's the Worst Microplastic Shedder
Every synthetic fabric sheds microplastics when you wash it. That's bad. But acrylic is in a league of its own.
730,000 microplastic particles released per wash from acrylic fabric — vs 496,000 for polyester (Plymouth University, 2016)
That's not a rounding error. Acrylic sheds roughly 47% more microplastic particles per wash than polyester. And polyester is already terrible. These particles are too small for most wastewater treatment plants to filter out. They end up in rivers, oceans, drinking water, and eventually your food.
The reason acrylic sheds so aggressively is structural. The fibres are shorter and less tightly bound than polyester filaments, so mechanical agitation in a washing machine rips them apart more easily. Every wash cycle sends hundreds of thousands of plastic particles into the water supply. There is no washing machine filter on Earth that catches all of them.
If you care about microplastic pollution, acrylic is the single worst fabric you can put in your wardrobe. Full stop.
Where You'll Find It
Acrylic shows up wherever brands want to sell you something that looks warm and cosy without spending the money on actual wool. Here's the hit list:
- Knitwear and sweaters — the number one hiding spot. That chunky knit jumper for $29.99? Almost certainly acrylic.
- Beanies and scarves — winter accessories are acrylic-heavy because consumers assume "knitted = wool."
- Blankets and throws — especially the suspiciously affordable ones.
- "Faux fur" — most faux fur is acrylic or modacrylic. You're trading animal fur for petroleum fur.
- Socks — acrylic is blended into socks marketed as "warm" or "thermal."
- Craft yarn — the majority of budget yarn at craft stores is 100% acrylic.
The pattern is consistent: if it's knitted, marketed as warm, and suspiciously cheap, check the label. It's probably acrylic.
Acrylic vs Wool: The Real Comparison
Brands use acrylic because it's cheap. Not because it's better. Here's how they actually stack up:
| Property | Acrylic | Wool |
|---|---|---|
| Source | Petroleum (fossil fuel) | Sheep (renewable) |
| Warmth | Decent insulation, loses it when wet | Excellent insulation, retains warmth when wet |
| Breathability | Poor — traps heat and moisture | Excellent — naturally temperature-regulating |
| Moisture | Hydrophobic, doesn't absorb sweat | Absorbs up to 30% of its weight in moisture |
| Durability | Pills quickly, loses shape | Naturally elastic, resists wrinkles |
| Odour | Holds onto smells | Naturally antimicrobial |
| Microplastics | 730,000 particles per wash | Zero |
| Biodegradable | No — 200+ years | Yes — months in soil |
| Price | Cheap | More expensive |
Acrylic wins exactly one category: price. Wool wins everything else. The "savings" on an acrylic sweater come at the cost of durability, comfort, and a staggering amount of microplastic pollution. A well-made wool sweater lasts years. A cheap acrylic one pills after three washes and ends up in landfill.
How to Avoid It
Avoiding acrylic is straightforward once you know what to look for:
- Check the label. Every time. Fabric composition is legally required on clothing labels. Look for "acrylic," "modacrylic," or "polyacrylonitrile." If any of those appear, you're holding plastic.
- Be suspicious of cheap knitwear. A wool sweater costs more than $30. If the price seems too good, the fabric probably is too.
- Look for natural fibres. Wool, cotton, linen, cashmere, alpaca. These are the real thing.
- Use Fibr. If you shop on Zara, H&M, or Mango, Fibr shows fabric composition right on the product image. You'll see acrylic coming before you even click on the product.
The brands won't make this easy for you. They bury composition data in fine print because they know "100% acrylic" doesn't exactly scream quality. That's why we built Fibr — to put the information where you can actually see it.