Why are Marine Biodegradable Biopolymers so important? And how they can be missed used!

PHA is mother's nature polymer (or plastic) made from bacteria. This biopolymer as the natural ability to return to nature without causing any long term negative effect. And at this time*, the ASTM or American Society for Testing and Materials highest standard for biodegradation is method 6691 - using standard 7081 (Rate of degradation of paper within a marine environment). It is simply far superior to any composting standards, as most other Biopolymers such as PLA requires ASTM 6400 that is only available in industrial digestors (or Anaerobic Composting). The fallacies in leaning on this "compostable" standard is simply two folds.?

1) The odds of a PLA straw or cup or fork to end up in the right composter that can handle the material aren't exactly great. 2019 study shows that out of 192 Composting facility in California, only 14 accept bioplastics. And only half of them actually did process the material. That's 3% of the potential capacity that can handle PLA responsibly. Hence why they need to include a disclaimer on PLA "compostable" bags as a suitable location may not be available within your area. And with a 3% availability, you would have better odds playing roulette in Vegas.?

2) ASTM 6400 method of validation and timeline, does not match what the composters operational time frame for the rotation of materials. They are in the business of turning waste into useful compost. And this normally required a degradation cycle to be less than 75 days. And not 90 days as the ASTM 6400 allows.?

This clear disconnect between a Standard and what the converters need is a serious issue that needs addressing. Either we change the standard to match, or we ask Composters to increase their cycle time.?

And this is where PHA's get the upper hand, as they do not require elevated temperatures, humidity or controlled oxygen levels in order to naturally decompose. Something PLA will never be able to achieve.?

The risk of not fully composting PLA is simply that it can in fact turn and build in the environment as a toxic microplastic. So partial decomposition is not an option either for PLA. As it must reach over 90% degradation before the remaining material is considered harmless or inert.?

PHA on the other hand does not require special conditions. It will simply adapt its natural biodegradation rate to match the environment it is exposed to. But at no time, will PHA's build up as toxic microplastics.?

The above image and attached data sheet show our results testing a long list of custom compounds manufactured at Beyond Plastic LLC. The conclusion is simply that while we have some very positive results, we can also have some failures. Our F0065 formulation was found to contain a small amount (less than 1%) of an additive that was petrol-based vs. sourced from bio-base. The result from F0065 shows a failure to reach the required degradation curve, therefore the material is unsuitable for any biodegradable claims.?

We also tested other materials sold on the market that are branded as biodegradable water Bottles and Closures. And the result clearly shows that they were not biodegradable by 6691-7081 standards.?

In conclusion, PHA's materials can greatly reduce plastic pollution. By being recyclable, compostable (in all forms and methods). And if discarded in our environment, they will simply biodegrade at the same rate as cellulose (paper or plant cell).?

However, this last important property is simply a fail-safe mechanism that needs to be regulated and enforced. Companies that misuse this material and make false claims are only going to further erode consumer trust in the science. And further contribute to the ever-increasing plastic pollution.?

*There is a new ASTM for Marine Biodegradation that is under test and review. This standard is far more stringent and addresses the issue of marine water conditions (being on average 4c). While we cannot share the specifics at this time, we can share the fact that Pure PHA is passing with flying colors.

Full data set and report is available on our website to download. We want to thank Prof Joseph Greene and his team at Chico State University for their work.