Plain-English Definition
Biodegradable is a broad promise that living organisms can help break a material down. Compostable is a more specific promise that the material can break down safely under stated composting conditions and become part of usable compost. It is the difference between saying something can happen and giving the rules for where, how, and how fast it happens.
What the Claim Usually Means
People often assume both labels mean an item can disappear harmlessly in a backyard pile, landfill, or natural setting. Heat, moisture, oxygen, microbes, time, and facility equipment can change the result completely.
What It Actually Proves
A well-supported compostable claim can show that every covered component breaks down safely in the stated system within a useful composting timeframe. A qualified biodegradable claim can describe the conditions and period in which the whole item returns to nature.
What It Does Not Prove
Neither word proves that an item belongs in a recycling bin, will break down as litter, or will decompose quickly in a landfill. Industrially compostable does not mean home compostable. A claim on one component does not cover inks, labels, coatings, adhesives, or the rest of the package unless the evidence includes them.
How It Is Measured
For an unqualified degradable claim on a solid-waste product, the FTC expects evidence that the entire item will completely break down and return to nature within one year after customary disposal. Items normally sent to landfills, incinerators, or recycling facilities generally do not meet that test. A compostable claim needs evidence that all covered materials break down safely at about the same rate as the other composted material. The label should also say whether home or municipal composting is required and disclose limited facility access when needed.
Common Misunderstandings
- Biodegradable means the item will disappear soon. The word needs a timeframe and conditions before soon means anything.
- Compostable means backyard compostable. Many products require the higher heat and controlled conditions of an industrial facility.
- A landfill provides good composting conditions. Buried waste may lack the oxygen, moisture, and controlled process the material needs.
- Compostable plastic belongs in plastic recycling. EPA says it can contaminate and disrupt the ordinary plastic recycling stream.
- Plant-based means biodegradable or compostable. The raw material does not determine the finished product's disposal behavior by itself.