Is polyester plastic?

What polyester actually is

Polyester is polyethylene terephthalate (PET), a polymer made from petroleum. The pellets that become water bottles and the chips that become your t-shirt start life as the same material — the only difference is whether the plastic is molded or melt-spun into filament.

It is the most produced fiber on earth: over half of all textile fiber made each year is polyester. If a garment is cheap, wrinkle-free, and quick-drying, polyester is usually why.

The microplastic problem

Every wash of a polyester garment sheds microscopic plastic fibers — studies measure hundreds of thousands of microfibers per household load. Wastewater plants catch many but not all; the rest flow into rivers and oceans, where they have been found in fish, sea salt, drinking water, and human blood.

Unlike a bottle, a fleece can never be effectively recycled once shed as fiber fragments. Shedding is worst in the first few washes and never fully stops.

How Plastfri scores it

Plastfri scores polyester at 100/100 — fully synthetic. A 65/35 poly-cotton blend scores 65. The score you see on a product is the percentage-weighted plastic content of its listed fiber composition.