In spite of continuous increases in the use of plastics since the 1970’s, landfill audits over time have regularly measured plastics in landfill at only 7 to 9% (by weight) of total materials disposed. Those percentages have remained constant for two reasons. “Down-guageing” (the use of thinner, lighter plastics with superior performance characteristics) and the success of recycling. Holding plastics at these disposed levels is a positive outcome and plastics, by design, are inert and no long-term threat to landfill. But, because plastics tend to be light, rigid and bulky, they typically occupy a disproportionate amount of space in landfill. Burial of plastics should be discouraged whenever practical. For example, foamed plastics (like cushion packaging and insulating panels) are only about 5% plastic and 95% inert gas.
As an option to burial, most thermo-plastics plastics are recyclable and, once cleaned and flaked or formed as a pellet, can be re-molded into new products. Recycling is a responsible option to burial and a useful waste-minimization tool.