Most people know synthetic fabrics shed microplastics — but not everyone knows that how you wash them can significantly affect how much they shed. Small changes to your laundry routine add up over time.
Why Synthetic Fabrics Shed Microplastics
Synthetic fabrics — polyester, nylon, acrylic, fleece — are made from polymer fibers that break down at their tips and ends during washing. The mechanical action of a washing machine loosens these tiny fibers, which then pass through standard machine filters (they’re too small to catch) and enter the wastewater system.
Research suggests that washing one synthetic garment can release hundreds of thousands to millions of microfibers per wash. While not every fiber makes it to open water (wastewater treatment plants catch a significant portion), a meaningful percentage does — and microplastics have been found throughout marine and freshwater environments, in drinking water, and in human tissue.
The good news is that washing behavior significantly affects how much is shed:
- Older garments shed more than new ones (the outer fibers have already been shed)
- Rough mechanical action sheds more than gentle cycles
- Hot water can break down fibers faster than cold
- Full loads create less friction than small loads
Best Washing Settings for Synthetics
Cold water, always. Hot water loosens synthetic fibers more readily than cold. Cold washing also uses less energy — it’s a win on both fronts.
Gentle cycle. Less mechanical agitation means less fiber release. The delicate or hand-wash cycle moves fabric more gently through water, reducing friction-based shedding.
Full loads (but not overloaded). A full load reduces the total amount of fabric-to-fabric friction per item. An underloaded machine has clothes tumbling against each other more freely; a full (not packed) load cushions this.
Shorter wash time. Less time in the machine means fewer cycles of agitation and less cumulative fiber release. If your machine has a quick-wash setting and your clothes aren’t heavily soiled, use it.
Skip the extra rinse. Additional rinse cycles mean additional agitation cycles. Skip unless there’s a real reason to run them.
Detergent and Laundry Tips That Help
Use liquid detergent, not powder. Powder detergent can be abrasive in the wash drum, adding to mechanical action that loosens fibers. Liquid disperses more gently.
Use less detergent. More detergent doesn’t mean cleaner clothes — but it can mean more foamy action that increases agitation. Stick to the recommended amount or slightly less.
Consider a laundry ball. Some laundry balls (not the magnetic or ceramic pseudoscience versions) work by physically separating clothes during washing, reducing inter-garment friction.
Avoid fabric softener on synthetics. Fabric softeners coat fibers and can actually loosen more fibers from the surface over time. Skip it for synthetics.
Laundry Tools That May Reduce Shedding
Guppyfriend Bag: A specially designed washing bag that you put synthetic garments inside before putting them in the machine. The bag’s filter structure captures fibers that shed during washing. Research by the Fraunhofer Institute found it captured a significant portion of microfibers released.
Cora Ball: A laundry ball designed to catch microfibers in the wash. Studies have shown mixed results — the Cora Ball catches a meaningful percentage of fibers but less than the Guppyfriend Bag. Still a meaningful reduction.
Washing machine filters (Lint LUV-R, PlanetCare): These are installed at your machine’s outlet and filter the drain water before it reaches the wastewater system. More comprehensive than a bag or ball — catches fibers from any garment, not just what’s in the bag — but requires installation.
Dryer sheets vs. dryer balls: Dryer balls (wool or silicone) create less static cling than dryer sheets without adding coating chemicals. For synthetics, air drying is preferable to any heat drying, which can break down fibers faster.
Drying Tips That Protect Fabric
Air dry when possible. Hanging synthetic garments to dry eliminates dryer agitation entirely, which both reduces shedding and extends the life of the fabric.
Low heat if machine drying. High heat is harder on synthetic fibers than low heat. If you use a dryer, low heat extends the garment’s lifespan and reduces fiber breakdown.
Don’t over-dry. Running the dryer longer than needed adds unnecessary heat and agitation. Pull synthetics out while slightly damp and let them finish air-drying.
FAQ
Does using a Guppyfriend bag actually work?
Yes — research by the Fraunhofer Institute found the Guppyfriend bag captured 86% of fibers that were released, and that garments washed inside the bag shed fewer total fibers than those washed without. It’s the most researched and effective consumer tool currently available.
Does washing synthetic clothes fewer times reduce shedding?
Yes — less total washing means less total shedding. Synthetics like merino wool alternatives (recycled polyester activewear) that can be worn multiple times before washing shed less per wear-cycle.
Is the first wash the worst?
Often yes. Many garments shed the most fibers in their first few washes as loose surface fibers are released. Running new synthetics through a cold, gentle wash with a filter bag before wearing can reduce later shedding.
Are top-loading washers worse than front-loading?
Front-loading machines are generally gentler on fabrics because they tumble clothes through water rather than agitating with a central post. If you have a choice, front-loading is better for reducing synthetic shedding.
Related reading: Microplastics in Clothing: What You Should Know · Do Leggings Release Microplastics?
Save clothes and reduce shedding. Download Wove for iPhone or Android to check your clothing’s fiber and shedding risk rating before you buy.
Sources
- Fraunhofer Institute: Microfiber Shedding Research
- IUCN: Primary Microplastics in the Oceans
- Plymouth University: Microfibres from Synthetic Clothing Study
- Patagonia: Microplastics Research Initiative