The word biodegradable on a label doesn't necessarily mean a product is environmentally safe?

Biodegradable means it SHOULD be safe for the environment. Meaning it can break down into natural elements. However, this is uncertain as some materials don't break down as easily, with a possibility of not having much of a difference as non-biodegradable materials. It all depends on the product, but if we're going by the label, then by definition it's environmentally safe.