The extent to which a substance can be decomposed - or rotted - by bacteria and fungi. Implies that residues from degradation are nontoxic. One of the most misleading claims in business, because shoppers often assume a biodegradable product to be harmless. Some harmful compounds take much longer to degrade than others and the product can harm the environment while it is rotting. Biodegradation may also be incomplete, sometimes leaving residues in the environment which are more harmful than the original substance. Accumulation in the environment of nonbiodegradable (or poorly biodegradable) substances, such as some biocides, can cause serious problems.