Plastics are polymers made of repeating monomer units that are chemically bonded together. They are resistant to chemicals and water, make good food packaging due to hygiene properties, and provide thermal and electrical insulation. However, plastics persist in the environment and can accumulate toxins. When burned, some plastics like PVC release highly toxic dioxins. Plastic debris is proliferating in oceans and waterways, harming wildlife that ingest or become entangled in it. The majority of plastic waste ends up in landfills or littering the environment.