Biodegradable compostable bag is a special kind of plastic bag which can be decomposed by microorganisms in a specific environment, and eventually turn into environmentally harmless substances, such as carbon dioxide, water and the mineralized inorganic salts of the elements it contains, as well as new biomass (e.g., dead microorganisms, etc.). These bags were originally designed to solve the problem of traditional plastic bags being difficult to degrade by adding specific ingredients or using biodegradable materials that can be decomposed by microorganisms in the natural environment, thus reducing plastic pollution.
The classification of biodegradable compost bags mainly includes:
Plastic bags with added corn starch or calcium carbonate: these bags are made by adding natural ingredients such as corn starch or calcium carbonate, these additives can accelerate the cracking of the plastic bags into small pieces but cannot make the plastic disappear completely.
Plastic bags with “photosensitizing accelerators”: This type of plastic can be broken into powder, but still maintains the properties of the plastic.
Compostable plastics (biodegradable plastics): These plastics do not contain traditional plastics (such as polyethylene PE, polypropylene PP, polystyrene PS, and polyvinyl chloride PVC), and rely on microorganisms to decompose them into organic matter, carbon dioxide, and water to make them truly biodegradable.
In order to ensure that compostable biodegradable plastics are truly biodegradable, the European Union, the United States, Japan, and Australia have all developed rigorous certification programs. The raw materials for compostable plastics are usually derived from renewable resources, such as corn and sugarcane, and can be chemically processed to obtain properties similar to petroleum-based plastics. Theoretically, these compostable plastics can gradually degrade over time into carbon dioxide, water, and other biomass, but if they are simply left in the environment, degradation can take much longer than we think. Therefore, for their environmental purposes, these plastics need to be collected and sent to specialized industrial composting sites for composting, where their decomposition process is accelerated through human-controlled conditions.
