Cheat Sheet: Biodegradable

life cycle of a leaf, from new growth, to biodegradation

Biodegradable. It’s a term that’s thrown around a lot these days. And with items ranging from disposable flatware and diapers to bags and balloons now available under the auspices of “biodegradability,” it is important to get the facts on what it all means.

Who Says?

Companies such as Coca-Cola, Solo Cup, International Paper, Glad, Whole Foods and Dixie Cup have all come to the biodegradable scene in recent years. According to the Biodegradable Products Institute (BPI), a leading third-party certifier of biodegradable claims, the word has gone “mainstream,” but with little oversight and legal regulation of what it really means.

Biodegradable means a substance is capable of being broken down, especially into innocuous (safe, not harmful) products by the action of living things, such as microorganisms.

For its part, the European Union considers a material biodegradable if it will break down into mostly CO2, water and organic matter within six months of being put into a composting facility.

The Federal Trade Commission, which regulates advertising and product claims in order to protect consumers from “unfair and deceptive acts or practices,” states that “an unqualified claim that a product or package is biodegradable should be substantiated by competent and reliable scientific evidence that the entire product or package will completely break down and return to nature, that is, decompose into elements found in nature within a reasonable short period of time after customary disposal.”

The FTC’s Environmental Marketing Claims Division uses these general guidelines for regulating biodegradable product claims. As “green” products have flooded the marketplace in recent years, the FTC is trying to keep up.

In a recent display of its authority, the FTC halted a retailer of rayon towels from claiming its product was biodegradable. The FTC alleged that the company’s products usually ended up in landfills, incinerators or recycling facilities, making it is impossible for the product to biodegrade within a reasonably short time.

Biodegrading vs. Degrading

Why are some biodegradable claims misleading, anyways? The above example of the rayon towel manufacturer shows that biodegradation is not something that just happens once a product is thrown out. Biodegradable products must be put through a specific chemical process at commercial composting facilities for their potential environmental benefits to be realized.

Thus, biodegradability and composting go hand-in-hand. When something is biodegradable, oftentimes a commercial composting facility is needed so that the materials residing in biodegradable products can be sufficiently heated, broken down into elemental compounds and eventually, returned to the ground as humus, a nutrient-rich soil amendment.

The definition of biodegradability is important to keep in mind because materials that remain after biodegradation are generally safe, as they have been broken down into elemental compounds such as:

Many of the inaccurately labeled “biodegradable” products do actually experience a significant chemical breakdown. Yet that degradation is incomplete. This lack of a full organic decomposition is the reason companies cannot claim biodegradability of certain products.

Some products that make biodegradability claims only degrade, which can leave potentially harmful materials behind. Take plastic, for example.

According to Global Environmental Polymers, because plastic is a non-naturally occurring substance, a plastic that is designed to degrade is one that undergoes a significant change in its chemical structure under specific environmental conditions, resulting in the loss of some of its original properties.

For example, because it only loses some of its chemical properties, plastic will never break down as biodegradable materials do (to the point where only elemental compounds remain).

The materials we use every day degrade and biodegrade slowly over time; it’s a part of life. However, when inaccurately labeled “biodegradable” materials inadvertently go through municipal composting facilities, they can contaminate water and soil because of the chemical compounds they leave behind, according to the BPI.

Common Perceptions and Misunderstandings

Additionally, according to the BPI, there is a common misunderstanding that products labeled “biodegradable” (even properly labeled ones) will decompose in the landfill and are therefore better for the environment.

However, due to the oxygen-poor and dry conditions associated with most landfills, rather than decompose, materials tend to stay relatively well preserved.

Here’s a perfect example: A trash study project conducted by the University of Arizona dug through more than 20 landfills across North America, and found “hundreds of undecomposed hot dogs, corn starch and lettuce dating back to the 1960s.” How did they know how old the food was, you ask? They used some of the still readable 2,425 newspapers they found to get the exact dates.

This is why commercial composting is a crucial step for biodegradable products to be environmentally effective. Once biodegradable products hit the landfill, they are as good as any other trash material.

Options Abound

Despite the difficulties in fighting improperly labeled products and keeping them out of the landfill, there are a plethora of biodegradable products helping to reduce the solid waste stream.

Biodegradable products are typically derived from natural, plant-based ingredients. For example, flatware made from potatoes, corn and wood is popping up at Whole Foods grocery stores and vegetarian restaurants across the country.

Some other biodegradable products include:

  • Compostable trash bags made from corn
  • Sugar cane and wheat fiber bowls, platters, and trays
  • “Agro-resins” – Plant-derived resins used for injection into molds as well as compostable bags and films
  • Compostable packaging materials made from cellulose

More examples of certified biodegradable products are available through the BPI.

Feature image by Siamlian Ngaihte from Pixabay 

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  1. PLA is being heralded as the new plastic that is going to save us from ourselves and BPI is often cited as the certifying agency that is keeping track of which plastics are to be labeled as biodegradable. BPI is a PLA organization which certifies plastics as biodegradable based on a criteria that was designed for PLA. PLA does not biodegrade in a landfill. PLA will compost but only in a commercial composting facility.

    PLA is getting a lot of spin from corporate marketing departments that have a lot of money and spin talent. We consumers aren’t all that good at separating the wheat from the chaff, but if we want a better environment, we should start getting environmentally smarter. Here is part of a study that discusses PLA. PLA may sound like the perfect idea and it very well may have niche market applications. Studies have shown that PLA has its own set of problems.

    “The conclusions from our analyses were inescapable. The environmental benefit of growing plastic in plants is overshadowed by unjustifiable increases in energy consumption and gas emissions. PLA seems to be the only plant-based plastic that has a chance of becoming competitive in this regard. Though perhaps not as elegant a solution as making PHA in plants, it takes advantage of major factors contributing to an efficient process: low energy requirements and high conversion yields (almost 80 percent of each kilogram of plant sugar used ends up in the final plastic product). But despite the advantages of PLA over other plant-based plastics, its production will inevitably emit more greenhouse gases than do many of its petrochemical counterparts.”

    Excerpt from:

    There are basically three types of plastics claiming to be more environmentally friendly; Compostable, Degradable and Biodegradable.
    As mentioned, PLA is compostable but only in a commercial facility. PLA doesn’t biodegrade, once it hits a landfill environment it will languish there for a long time.
    Degradable plastics such as oxodegradable plastics, break down (degrade) into smaller and smaller pieces until they are too small to see. Degraded polymers don’t biodegrade they just get to small to see and that isn’t good for the environment either.
    The third is a biodegradable plastic such as the ENSO Bottle with EcoPure or other plastics with the EcoPure additive. Biodegradable plastic with EcoPure is plastic that has an additive which attracts microbes that consume plastic in an anaerobic or aerobic environment leaving behind biogases and humus.

    As you mentioned, most landfills here in the U.S. are the dry tomb type where the trash is compacted and covered limiting oxygen and moisture within the trash. There is however, microbial activity within the anaerobic conditions of a dry tomb landfill which is why the government has mandated that landfill operators capture or burn off the gases produced in a landfill. . Microbes consuming trash in a landfill produce landfill gases (LFG). The good side of LFG’s is that many of these landfill gases are now being captured and used to produce clean energy.

    Our company is supporting anew landfill design called “Bioreactor landfills.” Bioreactor landfills are landfills which are designed to enhance microbial action and to capture all the LFG produced. Our company supports recycling and the development of bioreactor landfills. Ultimately, most thing end up in a landfill, biodegradable plastics and bioreactor landfills will be major factor toward improving our environment.
    We know there isn’t any one perfect answer, but we are working toward a solution that will help.

    “Bottles for a Healthier Earth”

  2. What we really need are more commercial and municipal composting facilities, which produce a valuable and useful end product that will support plant growth.

    Biodegradable and compostable differ in two regards, with compostable being the more stringent. Materials and goods that are compostable must biodegrade within a certain time frame and must not leave a toxic residue. So a log is biodegradable, but not compostable because it takes years to fully biodegrade. A cotton textile colored with dyes that contain heavy metals would be biodegradable but not compostable because it leaves a toxic residue (heavy metals).

    Time to fully biodegrade is critical to the commercial composter, but usually less important for the home composter who doesn’t usually need the finished compost on a tight time schedule. Items that are biodegradable rather than compostable because they don’t meet timing criteria can often become compostable withe shredding, chipping, grinding, etc. That log could could be made into sawdust which could reasonably go into a compost pile.

    On the other hand, there isn’t much you can do about the toxicity of an item. If the item contains potentially toxic or non-biodegradable substances there isn’t much you can do about it. They will be in your compost and if you use that in your vegetable garden, perhaps your food chain too.

  3. Lynn-
    Totally agreed. We need more commercial composting facilities for any of these biodegradable products to make a difference! It seems strange to have these biodegradable products before the sufficient composting facilities are in place. But perhaps since we have the products, now the commercial composting facilities will follow. Clearly, there is a bit of a disparity between the supply of biodegradable products and the availability of proper disposal.

  4. So what do I do with my biodegradable trash bag when it’s full of trash? I’ve been putting it in my trash can, but from what you’re saying that’s the wrong thing to do! Am I supposed to empty the trash from it and then compost the bag? I don’t think that will go over well with the trash collectors!

  5. Tanya,
    You raise a good point about the biodegradable trash bags. Ideally they are used to collect organic materials that would go off to a composting facility, bag and all. This might be the case for a special event where compostable plates and cups are used. Using biodegradable trash bags for landfill-bound household trash has fewer advantages since it may or may not break down in a landfill. Still, I use biodegradable trash bags at my house just because I don’t want to add more plastic to the world. It seems crazy to me to use plastic to throw away plastic, but I’m afraid there are no great solutions here.

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