Nylon vs polyester: both are plastic, and how they differ

Updated · 16 sources · How we research

Nylon and polyester are the two most used synthetic fibers. Polyester was 59% of the fiber made in 2024 and nylon about 5%. The choice between them is a choice between two plastics.

Is nylon plastic?

Yes. US law defines nylon as a manufactured fiber made of a “long-chain synthetic polyamide,” and both nylon and polyester are made by melting the polymer and extruding it through a spinneret. In the most complete count of plastic ever produced, polyester, polyamide and acrylic fibers make up 1,000 million tonnes of the 8,300 million tonnes made since 1950, and 600 million tonnes of them have already been thrown away.

What nylon and polyester are made of

  • Nylon 6 is polymerized from caprolactam. All commercial caprolactam is made from benzene or toluene.
  • Nylon 6,6 is made by condensing adipic acid with hexamethylenediamine. Adipic acid starts from cyclohexane.
  • Polyester is mostly polyethylene terephthalate (PET), made from ethylene glycol and terephthalic acid or its ester.

All three start as petrochemicals. Only 2.3% of nylon and about 12% of polyester came from recycled feedstock in 2024; recycled polyester is almost all from plastic bottles.

Nylon vs polyester at a glance

PolyesterNylonCotton, linen or wool
What it isPlastic (PET)Plastic (polyamide)Grown fiber
Made fromEthylene glycol and terephthalic acidCaprolactam, or adipic acid and hexamethylenediaminePlants and sheep
Share of world fiber, 202459%About 5%Cotton 19%
Microfibers it shedsPlasticPlasticNot plastic
Disperse dyes, the leading textile allergenYesYesThese dyes are made for synthetics
Odor after wearHighNo different from polyesterCotton and wool: mid to low
EU conventional moisture value1.5%5.75–6.25%Cotton 8.5%, linen 12%

What they shed

Both shed microplastic fibers in the wash. In a study of 37 consumer garments, polyester shed 161 mg of microfibers per kilogram of fabric per wash and woven nylon 27 mg, and a lint trap caught up to 90% of the polyester fibers but only 46% of the nylon ones. Another study found no significant difference in shedding between nylon, acrylic and polyester knits, and worn nylon shed significantly more than new nylon.

What they put against your skin

Disperse dyes are the most common cause of textile allergic contact dermatitis, and they are used to color polyester, acrylic, acetate and nylon. In one clinic study, 9 of 10 patients allergic to these dyes reacted to extracts of synthetic garments.

How they smell

Synthetic fabric holds body odor. In wear tests, polyester fabrics rated high in odor intensity while cotton and wool rated mid to low. When nylon and polyester were worn and compared directly, there was no overall difference in odor intensity between them.

The climate cost of nylon 6,6

Making adipic acid, the main ingredient of nylon 6,6, releases nitrous oxide: about 300 kg of N2O per tonne of adipic acid without controls. Nitrous oxide warms the climate 273 times as much as carbon dioxide over a century and stays in the atmosphere for about 109 years. In the US, 84% of adipic acid goes into nylon 6,6.

Is nylon better than polyester?

No. Nylon is plastic made from petrochemicals, sheds plastic microfibers, takes the same allergenic dyes and smells as strongly after wear. Swapping polyester for nylon swaps one plastic for another.

Fibers in this guide

Frequently asked questions

Is nylon plastic?

Yes. Nylon is a synthetic polyamide made from petrochemicals, melted and extruded into fiber. Researchers who tallied all the plastic ever made count polyester, polyamide (nylon) and acrylic fibers as plastics: 1,000 million tonnes of them since 1950.

Is nylon the same as polyester?

No. Both are plastic, but they are different polymers. US law defines nylon as a long-chain synthetic polyamide and polyester as a long-chain synthetic polymer that is at least 85% an ester of a substituted aromatic carboxylic acid.

Is polyamide the same as polyester?

No. Polyamide is the chemical name for nylon, and labels outside the US often use it. Polyamide and polyester are both synthetic polymers, so both are plastic.

Is nylon better than polyester for your health?

Neither is a healthy choice. Both are dyed with disperse dyes, the leading cause of textile allergic contact dermatitis, and worn nylon and polyester smelled equally strong in wear tests. Polyester also carries antimony catalyst residue that moves into sweat in lab tests.

Is nylon or polyester more breathable?

Both hold little moisture compared with natural fibers. Under EU rules the conventional moisture value is 1.5% for polyester and 5.75% to 6.25% for nylon, against 8.5% for cotton and 12% for linen.

Sources

  1. US Federal Trade Commission, Textile Fiber Products Identification Act rules, 16 CFR §303.7, Generic names and definitions for manufactured fibers. ecfr.gov
  2. Geyer R, Jambeck JR, Law KL (2017), Production, use, and fate of all plastics ever made, Science Advances 3(7):e1700782. doi.org
  3. US EPA (1995), AP-42 Compilation of Air Emission Factors, Section 6.9 Synthetic Fibers. epa.gov
  4. US Food and Drug Administration, 21 CFR §177.1500, Nylon resins. ecfr.gov
  5. IPCC (2006), 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 3 Ch. 3 Chemical Industry Emissions. ipcc-nggip.iges.or.jp
  6. Forster P et al. (2021), The Earth's Energy Budget, Climate Feedbacks, and Climate Sensitivity, IPCC AR6 WGI Chapter 7. ipcc.ch
  7. US EPA (2024), Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2022, Section 4.8 Adipic Acid Production. epa.gov
  8. Textile Exchange (2025), Materials Market Report 2025. textileexchange.org
  9. Vassilenko E et al. (2021), Domestic laundry and microfiber pollution: Exploring fiber shedding from consumer apparel textiles, PLOS ONE 16(7):e0250346. doi.org
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  16. European Parliament and Council (2011), Regulation (EU) No 1007/2011, Annex IX: Agreed allowances used to calculate the mass of fibres. legislation.gov.uk