In various parts of the world, there has been a phase-out of lightweight plastic bags. Single-use plastic shopping bags are usually distributed (for free) to customers by stores when purchasing goods. It is a popular method that is practiced in many countries for being a strong, cheap, and hygienic way of transporting items. Lightweight bags are commonly made from high-density polyethylene (HDPE) plastic. Problems associated with plastic bags include use of non-renewable resources (such as crude oil, gas and coal), disposal, and environmental impacts.