Since January 1, 2021, the revised plastic ban has come into force across various regions. A recent market survey conducted by reporters from Beijing News found that the degradable plastic bags available for sale fall into multiple categories, including biodegradable, oxo-degradable, and photodegradable variants, with a wide array of implementation standards. Even many industry insiders find it difficult to accurately identify degradable plastic bags by means of material texture or tactile feel.

From a regulatory perspective, what kind of plastic bags better meet the "degradable plastic" standards? What aspects of qualification verification should merchants pay attention to when sourcing from plastic manufacturers? What simple identification methods can ordinary consumers master? To address these questions, Beijing News reporters interviewed Liu Jun, Director and Professor-level Senior Engineer at the Shanghai Institute of Quality Inspection and Technical Research.

Beijing News: From a regulatory standpoint, what type of plastic bags complies with the "degradable plastic" standards?Liu Jun: The current national standard GB/T 20197-2006 Definitions, Classification, Marking and Degradability Requirements of Degradable Plastics categorizes degradable plastics into biodegradable plastics, oxo-degradable plastics, photodegradable plastics, and compostable plastics. However, the revised version of this standard has removed the performance requirements for oxo-degradable and photodegradable plastics.

Therefore, as of now, GB/T 20197-2006 remains in effect. Biodegradable plastic bags, oxo-degradable plastic bags, photodegradable plastic bags, and compostable plastic bags that meet the degradability requirements specified in this standard are all classified as degradable plastic bags.

In addition, the current national standard governing biodegradable plastic shopping bags in China is GB/T 38082-2019 Biodegradable Plastic Shopping Bags. A biodegradable plastic shopping bag refers to a bag product made from biodegradable resin as the primary raw material, featuring a carrying structure, and used for holding and carrying goods in sales and service venues.

Beijing News: Our market survey revealed plastic bags labeled with materials such as PE-D2W and (PE-HD)-D2W1 being marketed as "degradable plastic bags". Do these plastic bags comply with the requirements of the plastic ban?Liu Jun: D2W and D2W1 are oxidative biodegradable additives. Plastic bags made of PE-D2W and (PE-HD)-D2W1 are typical oxo-degradable plastic bags, which are included in the classification of degradable plastics under the current GB/T 20197-2006. However, the degradation process of such plastics merely reduces large plastic pieces into smaller fragments, eventually turning them into microplastics invisible to the naked eye. This not only hinders the recycling and cleanup of plastics but also poses greater harm to the environment when these fragmented plastics enter ecosystems.

In 2019, the European Parliament adopted EU Directive 2019/904, which stipulates that "single-use plastic products made of oxo-degradable plastics shall be prohibited from circulation in the markets of EU member states". Therefore, from the original intent of the plastic ban, the use of this type of degradable shopping bags is not recommended.

Beijing News: There are also plastic bags marked with PE-HD (i.e., high-density polyethylene) as the material, but merchants claim that degradable components have been added and label them as "biodegradable shopping bags". Is this practice compliant?Liu Jun: Only plastic bags that meet all technical indicators specified in GB/T 38082-2019 Biodegradable Plastic Shopping Bags can be labeled as "biodegradable shopping bags". Common biodegradable materials include polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polyhydroxyalkanoate (PHA). PE-HD, however, is not included in the scope of biodegradable plastics. Therefore, even if degradable components are added, plastic bags marked with PE-HD as the material cannot be classified as biodegradable shopping bags.

Beijing News: What simple identification methods can merchants or consumers use when purchasing degradable plastic bags?Liu Jun: Traditional plastic bags produce a loud, crisp sound when crinkled, whereas fully degradable plastic bags make a much softer, quieter sound and feel more pliable. When purchasing degradable plastic bags, consumers can look for the "double J" logo. The text label should include information such as the product’s material, degradation conditions, and product standard number. Currently, the genuine biodegradable plastic materials available on the market are typically PLA, PBAT, or a blend of PLA + PBAT + starch (St).

Biodegradable products require specific environmental conditions to achieve full degradation. Therefore, manufacturers must indicate one or more of the following degradation pathways: "soil degradable, compostable, marine environment degradable, freshwater environment degradable, sludge digestible, and high-solid digestible".

The product standard for biodegradable plastic shopping bags is GB/T 38082-2019 Biodegradable Plastic Shopping Bags. In addition, there are photodegradable and oxo-degradable plastic bags on the market that comply with GB/T 20197-2006 Definitions, Classification, Marking and Degradability Requirements of Degradable Plastics. As mentioned earlier, although these two types of plastic bags currently meet national standards, their degradation process only involves a reduction in size, and the potential environmental harm still exists. Therefore, from the perspective of the plastic ban’s original intent, the use of these two types of products is not recommended.

Beijing News: What aspects of qualification verification should merchants focus on when procuring plastic bags from manufacturers?Liu Jun: When making purchases, merchants should require manufacturers to provide product test reports that include degradability performance data. For products bearing the "double J" logo, the product’s biodegradation rate must be ≥ 90%, the content of heavy metals and specific elements must meet the requirements specified in the Guidelines for Classification and Labeling of Degradable Plastic Products, the disintegration rate must be ≥ 90%, and the product must pass ecotoxicity tests.

If the product complies with GB/T 38082-2019, its biodegradation rate should be ≥ 60%. For products adhering to GB/T 20197-2006: biodegradable plastics require a biodegradation rate ≥ 60%; compostable plastics require a biodegradation rate ≥ 60% and must meet various compost quality indicators; oxo-degradable and photodegradable plastics have different requirements for indicators such as the retention rate of tensile elongation at break and the reduction rate of weight-average relative molecular mass.

In addition, for plastic bags intended for food contact, manufacturers must also provide a test report complying with GB 4806.7-2016 National Food Safety Standard for Plastic Materials and Products in Contact with Food.

Beijing News: From a technical perspective, can biodegradable plastics be produced simply by adding degradable materials to the production process of conventional plastics, or does it require equipment replacement?Liu Jun: Conventional plastics are made from raw materials such as PP and PE resins, while biodegradable plastics use raw materials like PLA and PBAT resins. These raw materials differ significantly in terms of melting temperature and drying conditions. Therefore, to produce high-quality biodegradable plastic products, additional specialized equipment is indeed required.

Article Title: What Constitutes a "Genuine" Degradable Plastic Bag? An Expert Explains URL: https://en.szxylp.com/news/industry-news/what-constitutes-a-genuine-degradable-plastic-bag-an-expert-explains.html