Biodegradable garbage bags can be biodegradable completely in seawater? 

Translate by Hensein team


On October 13, 2021, the Environmental Friendly Polymer Materials Laboratory of Beijing Technology and Business

University tested biodegradable products the degradation capacity in the sea, using five blind plastic film samples

(that film can be made to all kinds of biodegradable nappy bags and compostable produce bags wholesale or

biodegradable drawstring bags etc.), commissioned by the Ministry of Agriculture and Rural Affairs. 

According to the commission, the laboratory quantified the biodegradation rate by releasing the detection method

of biological gases according to ISO and national standards, and observed the five biodegradable film samples in the

ordinary sea tanks (sea sand at the bottom, algae and clownfish). 

The sample been put into the daily fish tank of ornamental seawater fish. At the same time, in order to prevent the

sample from floating in the seawater, the sample is fixed with curved pins and sunk to the surface of the sea sand at

the bottom of the tank. 

Compared with the real field ocean environment, the degradation environment condition of the indoor fish tank is

relatively less. In addition to the constant room temperature condition, the fish tank lacks the tidal water impact force

(which will damage the samples) and more microorganisms. 


As can be seen from the figure above, the samples were released on October 13 after 35 days, and after 60 days, most

biodegradable film samples were completely degraded, no small fragments were observed in the fish tank, and algae

and clownfish grew normally. 

From the "experiment" results, these five blind samples the from the Ministry of Agriculture, the preliminary judgment is

completely biodegradable plastic film. 

Recently, there are many enthusiasts focus on whether biodegradable plastic bags can be completely biodegraded in

seawater, pls have a try to bury corn starch bags or biodegradable drawstring trash bags in the soil, or put biodegradable

nappy bags into fish tank environment (suggest more choose some environment and scene, to increase reproducibility,

reproducibility and scientific) observation, believe that can improve the accuracy of their judgment! 

In addition, in similar fish tank observations last year, some other biodegradable films can also be biodegraded under such

environmental conditions, because there are also microorganisms in seawater adapted to high salt environments. PHA and

PBAT materials can be completely biodegraded in about 30 to 60 days under seawater and 25± 3℃, but the PLA bidirectional

tensile film (thick thickness) has not been significantly degraded for about one and a half years (observation is still continuing).

The specific experimental process observation photos can be seen in the following figure.


PLA and PBS straws completely disappeared after 105 days.