You may have heard of propylene glycol in several contexts. It is used as a safer alternative to ethylene glycol in antifreeze, as a preservative in foods and cosmetics, as a solvent in some pharmaceuticals and as a carrier of nicotine and flavours in electronic cigarettes. Propylene glycol also appears in the list of substances used by Tom’s of Maine, a company that prides itself on using natural ingredients in the consumer products they sell. According to Tom’s: “We’re always thinking about natural ingredients, where they come from and what they can do for a healthy world. That’s because ingredients derived from nature and handled responsibly tell you something important about a product. Something that feels good. And feeling good is what our ingredients list is all about.”
In that ingredients list the source of propylene glycol is described as “natural gas from the earth.” This is ridiculous on many levels. Propylene glycol is made via standard synthetic methods from propene oxide which in turn is made from propene. It is true that propene does occur in small amounts in natural gas, but that is not from where it is sourced. Propene is made by the catalytic cracking of larger molecules in petroleum. Of course, whether the starting material for the synthesis of propylene glycol comes from natural gas or not is totally irrelevant. Petroleum is no less natural than natural gas.
This is not meant to impugn propylene glycol in any way. It is a safe enough chemical. But trying to build up its image by claiming that it comes from “natural gas in the earth” is pure nonsense. And I won’t even mention that there are all sorts of gases “in the earth,” hydrogen sulphide for example, which will do away with people quite nicely. Basically, the term “natural” which has become so common in marketing has also become meaningless. If one ignores processing, every substance in the world can be described as natural because all raw materials come from nature. Where else would they come from? A car could be described as natural since the metals, leather and plastics used all can somehow be traced back to substances that can be found in nature. We either need some proper definition of the term natural that can be applied to marketing or eliminate its use completely.