A plastic bag is any bag made out of a thin flexible plastic film. Plastic bags can be classified by the grade and type of plastic that is used and by the design of the bag. The most common material that is used to manufacture plastic bags is polyethylene. Plastic shopping bags are used the world over as an easy way to carry items bought.
The high molecular size of most plastics is one of the reasons that these materials are resistant to biodegradation. It is due to this lack of biodegradation that plastic proves to be a problem. Plastic in land fills constitutes up to 20% of the content in American landfills. These plastics are found to accumulate at the rate of 25 million tons per year. This means that the average American uses 80kg of plastic a year, while a European uses 60kg per year.