Plastic recycling codes are numbers used to identify the specific type of plastic used in each item. Plastic recycling symbols can appear as any number between 1 and 7. This number is surrounded by a triangle with three arrows that each point clockwise.
Each number indicates a different type of plastic, and thus, chemical makeup. Code 1 indicates polyethylene terephthalate and is often found in plastic water bottles. Code 2 is used for high-density polyethylene, the plastic often used in milk and water jugs. Code 3 stands for Polyvinyl Chloride, which is often found in food or detergent containers, mattress covers, bibs, peanut butter jars and certain bottles, as well as cling wrap. Low-density polyethylene, a plastic often found in soft, more flexible bags, such as those found at a grocery store, is labeled with Code 4. Polypropylene, labeled with Code 5, is used in flexible plastics such as those used to make things ranging from diapers to ice cream containers. Code 6 refers to polystyrene, a material often found in Styrofoam and more rigid plastics. Code 7 is unspecific and represents a number of other chemicals.
Consumers should exercise caution when using plastics marked with a number 3, 6 or 7. Numbers 3 and 6 are known to contain potential toxins that can be released from the material. Plastics marked with the number 7 may also fit into this category.