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Biodegradable materials include biodegradable natural polymer materials such as cellulose, starch, paper, etc., as well as biodegradable plastics obtained by biosynthesis or chemical synthesis.

Biodegradable plastic refers to degradation caused by the action of microorganisms existing in nature under natural conditions such as soil and/or sand, and/or specific conditions such as composting conditions or anaerobic digestion conditions or in aqueous culture fluids. Eventually it is completely degraded into carbon dioxide (CO2) or/and methane (CH4), water (H2O) and mineralized inorganic salts of the elements contained therein, as well as new biomass (such as microbial dead bodies, etc.).

It should be noted that every biodegradable material, including paper, requires certain environmental conditions for its degradation. If it does not have the degradation conditions, especially the living conditions of microorganisms, its degradation will be very slow; at the same time, not every kind of organism Degradable materials can quickly degrade under any environmental conditions. Therefore, when dealing with biodegradable materials, we should start from their environmental conditions and analyze the structure of the materials themselves to determine whether they are biodegradable materials. How to judge whether a material is biodegradable, internationally and China have issued a series of testing method standards, which are answered in the standard question.