What are compostable plastics?
Compostable plastics are a type of biodegradable plastic. They refer to plastics that, under composting conditions and through microbial activity, can break down within a certain period into carbon dioxide, water, inorganic mineral salts of the contained elements, and new biomass. Additionally, the resulting compost must meet relevant standards regarding heavy metal content, toxicity tests, and residual fragments. Compostable plastics can be further classified into industrial composting and home composting.
Compostable plastics degrade under specific conditions. If these plastics are carelessly discarded into the natural environment, such as seawater or soil, their degradation process becomes extremely slow. They cannot fully break down into carbon dioxide and water within a short period, making their environmental impact essentially no different from that of traditional plastics.
Moreover, research has shown that when biodegradable plastics are mixed with other recyclable plastics, they can compromise the properties and performance of the recycled materials. For instance, starch in polylactic acid (PLA) may cause defects such as pores and spots in films made from recycled plastic.
Composting can be classified into aerobic composting and anaerobic composting, depending on microbial activity and the presence of oxygen. Aerobic composting occurs in the presence of oxygen, breaking down organic matter into CO₂, H₂O, heat, and humus. Anaerobic composting, on the other hand, takes place in oxygen-free conditions, where anaerobic microorganisms degrade organic matter into CH₄, CO₂, H₂O, heat, and humus. Typically, when referring to composting, it is understood as aerobic composting.
How is industrial composting different from home composting?
Industrial composting refers to the controlled process in which microorganisms aerobically degrade solid and semi-solid organic materials at moderate or high temperatures, producing stable humus. The typical composting cycle lasts around 180 days, though with advancements in aerobic composting technology, the process can be shortened to as little as 30 days or even less.
Home composting, on the other hand, primarily utilizes household kitchen waste or garden debris for aerobic composting to produce compost for personal use. The composting period for home composting is generally longer than that of industrial composting but typically does not exceed one year.
Biodegradable Plastics Do Not Cause Environmental Harm
There is widespread concern about whether the byproducts of biodegradable plastics after degradation might cause secondary environmental pollution. To address this, strict regulations have been established, including limits on heavy metal content, as part of the degradation performance requirements for biodegradable plastics.
For compostable plastics, ecological toxicity tests—such as plant toxicity tests and earthworm toxicity tests—are conducted on the resulting compost. Similarly, for soil-degradable biodegradable mulch films, in addition to degradation performance and heavy metal content requirements, new international standards also include regulations on ecological toxicity.
Therefore, based on current standards, biodegradable plastics that meet regulatory requirements do not pose secondary environmental hazards after degradation.
Intelligent Compost Degradation Analyzer
BEP series Intelligent Compost Degradation Analyzer is a high-end intelligent compost degradation testing device independently developed by our company, leveraging years of experience in biodegradable technology and applications. It incorporates patented intelligent algorithms and follows a human-centered design philosophy.
The intelligent compost degradation analyzer operates based on the oxygen consumption principle (aerobic respiration principle). It determines the degradation capability of test materials by measuring the amount of carbon dioxide released during the biodegradation process. The device fully complies with the international standard ISO 14855-1: Determination of the ultimate aerobic biodegradability of plastic materials under controlled composting conditions — Method by analysis of evolved carbon dioxide Part 1: General method, as well as various national compost degradation testing methods.
►Temperature Control: From room temperature to -80°C
►Composting Containers: Available in sizes 9/12/18/24/30/36 (containers can be independently combined for separate testing)
►Real-time Measurement and Monitoring: Real-time monitoring of gas parameters in each channel, including: 1) Flow rate, 2) CO2 concentration, 3) Temperature, 4) Relative humidity, 5) Gas pressure, 6) Oxygen concentration
►Comes with dedicated biodegradation analysis software, enabling one-click generation of test reports
