China Technical association of China’s Shandong Province releases technical standards for naturally degradable plastics

On Dec. 27, 2021, the Shandong Quality Inspection Association of China’s Shandong Province released a set of standards called the “Technical specification for eco-degradable plastic resins and products” (T/SDAQI 048-2021), which came into effect on Jan. 27, 2022. It is classified as “association standards” in the country’s standards system.

In the standards, “eco-degradable plastics” refers to biodegradable and environmentally degradable plastics collectively. For these two types of plastics and products made of them, the standards define technical terms, requirements, test methods, inspection rules, etc. and set out required criteria for degradability and other properties.

Scope

The standards apply to the following types of plastics and products made of them:

  • Biodegradable plastics — Plastics that are ultimately decomposed into CO2, CH4, H2O, inorganic salts or other types of biomass plastics completely by microorganisms in nature under certain conditions
  • Environmentally degradable plastics — Plastics that are decomposed in the natural environment by heat, water, oxygen, microorganisms, insects or the combined effect of wind, sand, rain or mechanical force

Degradability requirements

Biodegradable plastics

  • The relative biodegradation rate must be ≥ 90 percent in a composting environment or a liquid culture medium. A relative biodegradation rate is the ratio of the degradation rate of a test material to that of a reference material.
  • The biodegradation rate of a pure organic substance, a mixture or an organic component that makes up more than one percent of the material must be ≥ 60 percent.
  • Each test should be finished after the biodegradation process reaches the stable phase. The test period must be no less than 45 days and no more than six months.
  • The volatile solid content must be ≥ 51 percent.

Environmentally degradable plastics

The degradability of environmentally degradable plastics after aging treatment must meet the criteria in the table below.

Percent elongation at break (vertical/horizontal) ≤ 5
Molecular weight Mw (molecular weight) reduction ≥ 70% and Mw < 10000 in ≥ 20% of the components
Carbonyl index ≥ 1.0

For the calculation method for carbonyl index (CI), see the appendix to the standards. For the measurement of percent elongation at break, see the GB/T 1040.1 and GB/T 1040.3 standards. For the measurement of molecular weight, see the GB/T 36214.2-2018 and GB/T 36214.4-2018 standards.

 

The full text of the standards (in simplified Chinese) is available at
http://www.ttbz.org.cn/StandardManage/Detail/57976/.