Almost half of the world’s yearly production of synthetic fibres is polyester, totalling around 11 million tons. The main catalyst used in polyester production is antimony, a known carcinogen and toxin that affects the heart, lungs, liver and skin. By-products of antimony cause chronic bronchitis and emphysema. They also pollute waterways.
Made from petrochemicals, these synthetics are non-biodegradable as well, so they are inherently unsustainable. Nylon manufacture creates nitrous oxide, a greenhouse gas 310 times more potent than carbon dioxide. Making polyester uses large amounts of water for cooling, along with lubricants which can become a source of contamination. Both processes are also very energy-hungry.
The long lasting nature of polyester and synthetics, however, give an argument to call these textiles sustainable.
A tiny fraction of the polyethylene terephthalate (PET) that makes bottles is recycled into fibers. This recycled polyester (rPET) is considered a green option in textiles today because the energy needed to make the rPET is less than what is needed to make virgin polyester in the first place, therefore saving energy. It also keeps these bottles and other plastics out of landfills, further preventing methane gas production that contribute to Global Warming.