Resource Intensity Analysis of Producing 21 Types of Plastic in Terms of Mining Activity

Abstract

Material flow analysis of plastics has attracted considerable attention for achieving sustainable production and consumption. However, the direct weights of each plastic have been analyzed alone, not considering the amount of natural resources as inputs for plastic production. Therefore, we analyzed the cradle-to-gate resource intensity of 21 types of plastics in terms of mining activity, using the total material requirement under the life cycle concept. It was found that the resource use for plastic production differs by up to approximately 10 times depending on the plastic type. By applying these findings to the material flow analysis of some countries and regions, we found that the quantity of natural resources was more than 20 times the original weight attributed to plastic production. By comparing resource use with greenhouse gas emissions, plastics with higher greenhouse gas emissions were found to have higher resource use, indicating a positive correlation, whereas the opposite trend was also found for some plastics. Considering plastic alternatives, we found that the quantity of natural resources in plastic-based shopping bags is nearly equivalent to that in paper-based bags, whereas that in plastic-based straws is greater than that in paper-based bags. Focusing only on the direct weight of plastic may mislead the decision-making process.