Plastic bags are bad but they are not (all) “made from oil”

by Michael Smith (Veshengro)

It is a misconception that the majority of those “free” plastic grocery bags are made from oil, especially foreign oil.

Plastic bags are either made of a byproduct of natural gas or of a byproduct of oil, not of oil or natural gas itself. It is a misconception to say that they are made from oil.

Plastic bags are made from ethylene, a byproduct of natural gas or from ethylene created from naphtha, a byproduct of petroleum.

Chemists string together long chains of ethylene to form polyethylene. Depending on the process used to create the chains different densities of polyethylene can be produced.

As polyethylene is a byproduct, whether from natural gas or made from naphtha, which is a byproduct of the petroleum industry, those bags, really, but no more demand on the oil reserves and oil imports or those of natural gas, than does the demand for oil for the refineries anyway but they still remain unsustainable products.

The bags you are given at retail and grocery stores checkouts are High Density Polyethylene or HDPE. They are fairly sturdy, able to hold quite a bit of weight without breaking, optically cloudy, and can be dyed any color.

Low Density Polyethylene or LDPE are optically clear bags, very light, and often described as wispy. These bags are likely to be found in the produce market or covering your clothing at a dry cleaner.

In some countries, such as the USA, for instance, most of the plastic bags given away by grocery stores and others are made not from oil but natural gas, and the USA has ample supply of natural gas within its own borders – so no costly imports. Other countries are not so lucky.

In addition it has to be said that that only applies if the bags are actually produced in the USA and not, as will be more likely the case, in places such as China (or India). The source of the ethylene from which the polyethylene is then constructed we do not know.

Whatever the source, the fact remains that Plastic Bags Are Bad For The Environment

Most of what you have read about plastic bags is true. Plastic bags kill wildlife, cause pollution, clog landfills and indirectly raise the price of food at the grocery store. There are also, aside from those made from PLAs, that is to say those that are made from a plastic made from corn starch and lactic acids and such, no biodegradable plastic bags about. That is a fallacy and absolute greenwashing. Ordinary polyethylene shopping bags do NOT biodegrade; they photodegrade. That is to say they break down into ever smaller and smaller particles of plastic in the environment, all the while releasing harmful substances into the soil and water.

I strongly recommend the use of reusable grocery bags. They hold more, look better, and are not likely to leave your groceries strewn around the grocers parking lot.

Let us, however, clear up the misconception that plastic bags are made from oil. If they are made “from oil” then it is from a byproduct of the petroleum industry, namely naphtha. They are not, however, made from oil as oil goes. Therefore they are neither made from primarily from foreign oil or such.

We have enough strong and valid points as to why we should reduce or even ban the use of plastic bags without mentioning the oil factor in it at all.

However, whether made from a byproduct of oil or natural gas, that is to say from ethylene, they may actually come a long way to us as well, as I have said already. That too should be another reason, atop of the others, why we should get away from the free plastic grocery bag.

© M Smith (Veshengro), July 2008