In January last year, the Opinions on Further Strengthening Plastic Pollution Control issued by the National Development and Reform Commission and the Ministry of Ecology and Environment was called “the strongest plastic limit order in history”. Beijing, Shanghai, Hainan and other places have accelerated the implementation of the plastic limit order. Chengdu version of “The Strongest Plastic Restriction Order in History”-”Chengdu Action Plan for Strengthening Plastic Pollution Control” will also enter everyone’s life together with 2021.
“But the standard is really a bit more, it feels quite chaotic, and there is no idea yet.” The standard mentioned by Mr Yang, who is engaged in the production of plastic products, refers to the standard of degradable plastic bags. In addition to Mr. Yang, many citizens are confused about the standard of “plastic limit order”. “I am very supportive of plastic limit, but I don’t know which one is degradable plastic bag.”
Which kind of degradable plastic bag is it, and should the standard be marked? The reporter inquired about relevant standards and interviewed testing institutions.
Offline Shangchao
Degradable plastic bags have different standards, and the materials have different handfeel
The reporter visited the site and found that the standards of degradable plastic bags used by offline supermarkets are not consistent.
The biodegradable plastic shopping bag used in familymart is marked by GB/T38082-2019. According to the manufacturer, this is the standard widely used in degradable plastic bags in the industry.
However, the plastic shopping bags used in WOWO convenience stores only have the words “degradable environmental protection bags”, without marking the production standards or plastic types. This plastic bag feels slightly different from familymart’s, it feels thicker and has a smoother surface.
In addition, the standard on plastic bags of three supermarkets is Plastic Shopping Bags (GB/T21661-2008). Some plastic bags that implement this standard are printed with the slogan of “environmental protection’ bag’ going home”. Is this kind of plastic bag degradable? Merchants said that they are not degradable plastic bags, and the words “environmental protection” are written in the hope that everyone can use them many times.
In addition to visiting Shangchao, the reporter saw in a sales center in Erxianqiao that there are two kinds of degradable plastic bags sold here. One is similar to the one in WOWO convenience store, with smooth surface, and the other is similar to the degradable plastic bag used in familymart, with lighter weight.
Online inquiry
Implement a variety of standards, and standards vary from region to region
After entering “degradable plastic bags” on the shopping website, the reporter consulted five or six stores with the highest sales volume, and learned that the degradable plastic bags sold online mainly include three categories: biodegradation, starch-based degradation and photodegradation.
Among them, biodegradable plastic bags are commonly referred to as fully biodegradable plastic bags, and the implementation standard is GB/T38082-2019. The mixture of PBAT+PLA and PBAT+PLA+ST is adopted, and the relative decomposition rate is over 90%. Soft material, translucent bag, natural degradation, and relatively expensive price.
Starch-based degradable plastic bags contain bio-based corn starch ST30 degradable material, and the implementation standard is GB/T38079-2019. ST30 plant corn starch mixture is adopted, and the bio-based content is 20%-50%. The material is slightly soft, the bag is milky and yellowish, which can be buried and degraded, and the price is moderate.
The photodegradable plastic bag is made of photodegradable mineral and inorganic powder MD40, and the implementation standard is GB/T20197-2006. The mixture of PE and MD40 degradable particles is adopted, and the degradation rate is over 30%. The material is hard to the touch, milky white bag, which can be incinerated into powder, buried and photo-oxidized, and the price is economical and practical.
Except for the above three standards, the reporter did not see GB/T21661-2008 in the inspection report provided by the merchants.
Some merchants said that many local policies are different, depending on where they are used. “Biodegradation is generally used in coastal areas, and it is required to achieve 100% complete degradation in water. At present, Hainan requires full biodegradation, and starch degradation and photodegradation can be used in other areas.
Standard distinction
The standard has made it clear how to mark it: “mark it on the product or outer packaging”
The standards for degradable plastic bags are dazzling. Are the above standards effective? The reporter inquired about this issue in the national standard full-text disclosure system and related websites of the industry. Except that “GB/T21661-2008 plastic shopping bags” was abolished on December 31, 2020 and replaced by “GB/T 21661-2020 plastic shopping bags”, all other standards are currently valid.
It is worth noting that GB/T 20197-2006 defines the definition, classification, marking and degradation performance requirements of degradable plastics. According to this standard, under the specified environmental conditions, after a period of time and including one or more steps, the chemical structure of materials will change significantly and some properties will be lost, or plastics will be broken into degraded plastics. According to its design, the final degradation ways of degradable plastics include biodegradable plastics, compostable plastics, photodegradable plastics and thermooxidative degradable plastics.
At the same time, it is proposed in this standard that when using signs for degradable plastic products, they should be marked on the products or outer packaging. The photodegradable polypropylene plastic sheet produced according to this standard contains 15% mineral powder and 25% glass fiber by mass, and 5% photosensitizer is added. The length, width and thickness are 500mm, 1000mm and 2mm respectively, which is expressed as GB/T20197/ photodegradable plastic PP-(GF25+MD15)DPA5.
Post time: Apr-17-2021
