The 5 Gyres research institute says bioplastics are "not a silver bullet solution" for plastic pollution, following a study that raises concerns about so-called biodegradable products.
In its Better Alternatives 3.0 report, the Californian non-profit found that while bioplastics degrade faster than their fossil-derived counterparts, some degrade much slower than others.
The study found that some bioplastic packaging did not decompose after being buried underground for more than a year, regardless of the climate and soil conditions.
5 Gyres tested the biodegradability of 22 types of packaging including PLA straws
Researchers at 5 Gyres tested the degradation of 22 types of single-use packaging, with each type tested in both soil and sea for a total of 64 weeks, on sites in Florida, California and Maine. In all three locations, straws made from polylactic acid (PLA) ? a bioplastic made from corn starch or sugar cane ? decomposed in the ocean but remained largely intact when buried underground.
Other common types of bioplastic packaging showed little or no signs of degradation after 64 weeks in soil, with forks, bottles and tampon applicators among them.
PLA forks did not fully decompose at any of the test sites
Lisa Erdle, director of science and innovation at 5 Gyres, said the results prove that bioplastics are not a one-size-fits-all fix for plastic pollution, despite what their biodegradable labelling might lead people to assume.
"There is no silver bullet s...