Waste hierarchy is a classification of waste management vis-a-vis environmental impact that considers: prevention; re-use, recycling, energy recovery as well as disposal. The aim of waste hierarchy is to get maximum benefits and create the minimum amount of waste. The 3 Rs represent the hierarchy which categorizes waste from least to the most desirable. Many things we discard could be reused again with some imagination. Certain types of waste can be recycled and others must be handled more carefully. The Thai version of recycling involves sorting of materials into biodegradable, hazardous and recyclable (or not).