12 months under sealed conditions (prevent damage from moisture, soil, light, etc.). Those that are over 1 year old and within 1.5 years can still be used, but the edge sealing of the bag is not as good. The physical properties of degradable bags will slowly decrease with time, referring to the edge sealing, stretching, toughness and other physical properties. Bags will not be degraded if stored directly under normal conditions (avoid light and moisture). The premise of degradation must be the presence of microorganisms. Therefore, composting degradable bags requires a certain environment. But in fact, the back-end processing of degradable bags currently does not have a perfect processing system and has certain limitations. Therefore, some brands are excluded from degradable bags. Viscose fiber bags and paper bags do not have this restriction and meet the requirements of deplasticized packaging.

Degradation under composting conditions, home composting degradation time 12-18 months, industrial composting 3-6 months. Composting conditions: moisture (humidity) above 95%, soil, temperature (28-58 degrees), specific microorganisms.

Materials that can only be degraded into small fragments and cannot be converted into water and carbon dioxide within a specified time. Photo-oxidative degradation (D2W) adds 1-2% photo-oxidative additives to traditional PE materials. There are also PE and starch mixed materials, in which the starch part can be degraded, but the remaining PE part is still not degradable.

Infrared spectroscopy (comparing molecular structures) can be used to quickly identify the composition of plastic bags; chemical cracking methods can also be used (biodegradable materials can be quickly cracked under hot alkaline conditions, while ordinary plastic bags will not crack). The simplest and fastest method is combustion. Degradable bags burn with a neutral smell, while ordinary plastics burn with a pungent smell.