Decomposition of plastic can be broken down in the sun. The addition of starch to plastics makes it easier to decompose, but the decomposition is still incomplete. Most people use genetically engineered bacteria to produce completely biodegradable plastics, but the costs are still high. BASF, a German company, has developed a biodegradable plastic called ecoFLEX for food packaging. The above-mentioned biodegradable plastics are rarely used because of cost problems. The plastic must be exposed to the air in order to decompose, so if buried, it will still cause the problem of solid waste.
To facilitate the recycling of plastic, the United States Plastics Industry Association proposed the use of plastic types to classify the label system: "Synthetic Resin identification Code" (Resin identification Code, often translated as "plastic material encoding" or "Plastic Code"). Recyclable plastic containers will be accompanied by a triangular label of three arrows that will indicate the type of plastic.
