Acrylic yarn isn’t dangerous to use in most everyday projects, but it does carry real environmental costs and can cause skin irritation in some people. It’s one of the most popular yarns in the world because it’s cheap, soft, and machine-washable, yet it’s a petroleum-based plastic with a lifecycle that creates problems at nearly every stage. Whether those tradeoffs matter depends on what you’re making, who you’re making it for, and what you care about most.
What Acrylic Yarn Is Made Of
Acrylic yarn is a synthetic fiber made from a chemical called acrylonitrile, which is derived from petroleum or natural gas. Over 4 million tons of acrylonitrile are produced globally each year, and acrylic fiber is one of its primary end uses. During manufacturing, the raw chemical is polymerized into long chains and then spun into fibers that mimic the look and feel of wool.
The finished fiber is chemically stable, meaning the acrylonitrile is locked into the polymer structure rather than floating around loose. This is why a finished acrylic scarf or blanket doesn’t off-gas in any meaningful way under normal use. The health concerns with acrylonitrile exposure are concentrated in manufacturing facilities, not in your living room. That said, some acrylic yarns are treated with chemical finishes during production, including dyes, softeners, and anti-static agents, and those surface chemicals are what can occasionally cause problems for the end user.
Skin Irritation and Sensitivity
The most common complaint about acrylic yarn is that it feels scratchy or irritating against the skin. For most people, this is a texture issue rather than a chemical one. Acrylic fibers don’t breathe the way natural fibers do, so they can trap heat and moisture against the skin, which leads to itchiness, especially in warm environments or during physical activity.
A smaller number of people do experience genuine allergic contact dermatitis from acrylic textiles. This is typically a reaction not to the acrylic fiber itself but to residual chemicals from the dyeing and finishing process. Acrylate compounds, which are used in various textile surface treatments, are a recognized cause of allergic skin reactions. Symptoms include redness, itching, and sometimes small blisters where the fabric touches the skin. If you’ve noticed a pattern of skin irritation from synthetic fabrics but not from untreated cotton or wool, a chemical finish is the likely culprit.
For baby items, this question gets more attention. If you’re knitting or crocheting for an infant, look for yarn certified under the OEKO-TEX Standard 100 program, which tests textiles against a list of over 1,000 harmful substances. Their strictest product class, Class 1, is specifically designed for babies and children under three, with the tightest limits on chemical residues. Many acrylic yarns carry this certification, which provides a reasonable assurance that surface chemicals have been kept within safe thresholds.
Microplastic Shedding
This is where acrylic yarn’s environmental story gets serious. Every time you wash a synthetic textile, tiny plastic fibers break off and flow into the water. These microplastics are too small for most wastewater treatment plants to fully capture, so they end up in rivers, oceans, and eventually the food chain.
How much fiber sheds per wash depends heavily on how the yarn was spun. Research on synthetic staple fibers shows enormous variation: some spinning methods release as little as 16 milligrams of microfibers per kilogram of fabric per wash, while others shed over 1,700 milligrams per kilogram. Acrylic tends to shed more than polyester in head-to-head comparisons because its fibers are typically shorter staple lengths, which break free more easily. The first few washes are the worst, with shedding rates dropping after that initial period.
You can reduce microplastic release by washing acrylic items less frequently, using a microfiber-catching laundry bag, or installing a lint filter on your washing machine’s drain hose. Cold water and gentle cycles also help, since aggressive agitation breaks more fibers loose.
Decomposition and Waste
Acrylic yarn can take up to 200 years to decompose in a landfill, on par with other petroleum-based synthetics like polyester and nylon. Unlike wool or cotton, which break down within months to a few years under the right conditions, acrylic just sits there. And the recycling picture is bleak: more than 99% of acrylic-containing textiles are currently discarded rather than recycled. The technology to recycle acrylic fibers back into usable yarn exists in experimental settings, but it hasn’t scaled to any meaningful degree.
This means that the acrylic blanket you crochet today will almost certainly end up in a landfill eventually, and it will outlast you there. For a single cherished item that gets decades of use, the per-year environmental cost is modest. For fast, disposable projects or items that wear out quickly, the math looks worse.
How It Compares to Natural Fibers
Natural yarns have their own environmental costs. Conventional cotton requires enormous amounts of water and pesticides. Wool production generates methane emissions and raises animal welfare questions. Even “eco-friendly” fibers like bamboo rayon are often processed with harsh chemicals. No yarn is perfectly clean.
Where acrylic clearly loses is end-of-life impact. A cotton dishcloth will compost. An acrylic one won’t. Acrylic also loses on microplastic pollution, since natural fibers that shed in the wash are biodegradable (though treated cotton sheds significant microfibers too, they break down faster in the environment). Where acrylic wins is affordability, durability, colorfastness, and ease of care. It’s machine washable, hypoallergenic for most people, and holds up to heavy use, which is why it dominates the market for blankets, hats, and children’s items.
Making a Practical Choice
If your main concern is skin safety, acrylic yarn is fine for the vast majority of people. Choosing an OEKO-TEX certified yarn adds an extra layer of assurance, particularly for baby projects. If you notice itching or redness, try washing the finished item before wearing it to remove surface chemicals, or switch to a different brand before ruling out acrylic entirely.
If your concern is environmental, the honest answer is that acrylic is one of the less sustainable yarn choices available. It’s made from fossil fuels, sheds microplastics with every wash, barely gets recycled, and persists in landfills for centuries. You can offset some of this by making items that last, washing them thoughtfully, and donating rather than discarding them. But if minimizing your environmental footprint is a priority, natural fibers or recycled blends are a better fit for projects where acrylic isn’t strictly necessary.
For projects that need to survive frequent machine washing, like baby blankets, kids’ sweaters, or household items, acrylic’s practical advantages are hard to match at its price point. The tradeoff is real, but so is the usefulness.