Terms like “biodegradable”, “oxo-degradable”, and “photo-degradable” sound like they are the same as “compostable.” However, these products will not compost at a commercial compost facility as they contain components of plastic and will need to be removed manually by the facility to avoid contaminating an entire batch of compost.
The term “biodegradable” or similar terms are often used as a marketing tactic in film plastics to make consumers think they are environmentally friendly. The truth is most of these products are just polyethylene products that have additives which cause them to fragment into smaller pieces of plastic which remain in the environment for years to come.
There is no standard specification against which to measure the term “biodegradable”, thus it really doesn’t mean much of anything. “Certified Compostable”, on the other hand, is measured to ASTM D6400, the standard specification test for compostability, which allows manufacturers to print the BPI logo on their products and packaging.