What does biodegradable really mean?

By Lori Huskey

Degradation is simply breaking down into component parts, with chemical transformation in the process, perhaps. Biodegradation implies that degradation takes place within nature, and as you mention, in a landfill process the elements of nature that would degrade your corn-based coat hanger -- air, water, aerobic microbes, to name a few -- are not particularly present. Hence, alternative plastics may or may not be biodegradable to the extent that you imagine.

You may or may not know about the number of biodegradable products available to you. For example a lot of universities and large businesses with cafeterias are able to use compostable eating products like forks, plates and cups made with biodegradable corn-plastic. Other products include clothes hangers, credit cards, and trash bags.

There are a few standards for biodegradability to which a producer might adhere, but little oversight for those using the word. The Federal Trade Commission is in charge of deceptive advertising claims, and has put out some general guidelines for all environmental claims on products. They would like it if the word biodegradable were used only to "mean that the materials will break down and return to nature within a reasonably short time after customary disposal. What a 'reasonably short time' is depends on where the product is disposed."

The FTC also cautions consumers to critically read all eco-labeling claims, which is great advice and will help clarify your imaginings. If a producer has a substantiated claim about the low impact of its product, it should be able to give details. You might imagine, for example, when you see the "biodegradable" claim, that the product will biodegrade at your landfill. "Biodegradable in landfills" would be an example of a clarifying label.

Another standard of biodegradability is the voluntary testing guidelines set by the standards organization ASTM International. They have guidelines for degradation in composting operations, in water, in anaerobic conditions, and I'm sure many others. Unless the producer specifies they have used the ASTM standards, you need to inquire to find out.

Usually the only way to know the true biodegradability of a product is to call the producer and ask: If I put my corn-based coat hanger in the landfill, how long will it take to degrade? Hopefully they will be honest. The coat hanger may not degrade naturally, but perhaps it would if run through an industrial composting process replete with chipping and high temperatures.