Synthetic (chemically produced) fabrics are made by joining monomers into polymers, through a process called polymerization. A synthetic fabric, when magnified, looks like plastic spun together. Chemicals used to make synthetic fabric include sodium hydroxide and carbon disulfide, which are derived from coal, oil, or natural gas. Pressure forces the liquid chemicals through tiny holes called spinnerets. As the liquid comes out of the spinnerets and into the air, it cools and forms tiny threads. Manufacturers add artificial dyes to these threads before weaving them into a fabric.
Synthetic fabrics have many different qualities—including some not achievable with natural fibers. Synthetic fabric can provide waterproof fabrics and elastic fabrics for swimwear and underpants. Depending on the synthetic fabric, various added chemicals can make it softer, wrinkle free, flame-resistant, water-resistant, stain-resistant, or moth-repellent. While all these qualities are desirable, the processes can harm the environment, wildlife, and people's health.
Synthetic fabrics are often non-biodegradable, meaning that when discarded, they do not break down in soil, and the chemicals used in their manufacture can reach out and harm the environment. This is why synthetic fabric products must be discarded safely.