Polyethylene is a plastic that has become part of our lives more than you might realize. It was discovered by accident about 84 years ago after science experiments that should have exploded didn’t. Companies that made it were going out of business around the 1950s, but they were saved by – of all things – the hula hoop. Now it is found in everything from plastic bags to bullet-proof vests. When combined with glycol, it takes on a whole new form with a whole different set of uses. Here’s why it’s such great stuff.
The Technical Side of PEG
Polyethylene Glycol (PEG) is non-toxic, which is an important point when you see how it’s used. It has a slight alcohol smell but no color, and doesn’t evaporate easily. It dissolves well in liquids and doesn’t react with other materials. There are several different grades of PEG with varying molecular weights, which is what makes it thicker or thinner. The molecular weight is where the PEG number comes from; the higher the number, the thicker the substance. For example, PEG 700 is a clear, thick liquid. PEG 1000 and higher becomes waxy and solid. Since it dissolves in liquid, it can act as a thickener.
How PEG Is Used
The most common use of PEG is as a laxative. The National Institutes of Health says that PEG has a “marked accelerating effect on small intestinal liquid transit,” which basically means it will clean you out. Two major laxative brands (MiraLAX and Dulcolax) both use PEG. It is also used for “whole bowel irrigation,” part of a doctor’s preparation to examine the colon. Some other personal (but not so personal) uses include oral care products like toothpaste, breath fresheners, and mouthwashes, as well as skin creams, moisturizers, and eye drops.
PEG also has other not-so-personal uses. PEG is used to fill paintballs since it is thick and flexible. It is used to replace water in wooden objects, which gives the wood lasting strength. It is also used as an anti-dusting agent in agricultural products, in cleaners, detergents, paint dye, packaging products, as a non-stick agent for mold products, as a color stabilizer for paper products, and many other items that we depend on daily.
PEG 300, 400, and 600 are most often used as lubricants, inks, in food packaging, and as adhesives. Prior to using this chemical in a food-related product, read the FDA guidelines on the use of the chemical.