EVEN MORE BAD NEWS FOR “COMPOSTABLE”
Following the report from Spain mentioned last week on the toxicity of the type of plastic marketed as “compostable” there is another report, this time from the Fraunhofer Institute in Germany, saying that they do not recommend the use of plastic bags in the composting process. During the study they distributed 400,000 bags made from different raw materials (Ecovio®, Mater-Bi® and wax-coated paper bags) to 10,000 households.
See Fraunhofer Study
This report confirms my view that the type of plastic aggressively marketed as “compostable” is essentially useless, and I cannot understand why anyone buys it. See Composting
The report says “Bags made from biodegradable materials for collecting organic household waste have been available on the market for several years. Now researchers have conducted an extensive investigation into whether these bags fully decompose. In addition, this — the first of its kind — study also took a look into the consumer’s interest in using biodegradable bags. For numerous reasons, the researchers are not currently recommending the use of biodegradable organic waste bags.”
“Both conventional plastic bags and the ones made from biodegradable plastics need to be separated before the organic waste goes for recycling, so they don’t end up in the compost waste fraction. This is a time-consuming undertaking, and some valuable organic material always gets lost in the process.”
“If bags made from biodegradable materials do not completely degrade in the biowaste recycling plants and are just broken down into micro- and nanoplastic particles instead, they could make their way into the environment with the compost.”
Through their tests, they were able to prove that composts contain large amounts of microplastics of less than 1 millimetre in size, and that these can remain in the soil over long periods of time. The project group’s initial evaluation is that “we should avoid introducing biodegradable bags into real, large-scale biowaste re-cycling plants until it can be guaranteed that the bags will break down completely. In addition, using paper bags and bags made from biodegradable materials did not positively influence how much organic waste households put out for collection.”
I have noticed that people who rent space on the White City Campus of Imperial College London are good at attracting funding for re-inventing the wheel.
FlexSea, a startup company, has announced the completion of a funding round worth £3 million in equity and grants for a range of packaging products based on plastics derived from seaweed. However, a company called Eranova in France has been making plastic from seaweed for several years now.
Flexsea say that “the aim is to address the catastrophic impact of conventional plastics on the environment, in particular the single-use plastic products that persist in the ocean for many hundreds of years after they are discarded.
The way to stop them persisting in the ocean is to use biodegradable technology, such as d2w (www.d2w.net) which has been available on the market for more than 20 years. It gives the plastic a programmed service life, during which it will have the same strength, clarity, and other properties as conventional plastic, but if discarded in the environment it will convert rapidly into biodegradable materials. See Why biodegradable?
FlexSea claim that their biodegradable plastic will break down in the sea or the soil within a matter of weeks, but is it any use as a packaging material?
The MVTR and OTR are critical in food packaging, so if this plastic material is sensitive to moisture it will lose its mechanical properties immediately after being exposed to moisture. It can only be used for Semi-dry foods and will fall apart if it gets damp.
They mention oxygen and fat barriers, but moisture vapour transmission is the critical one and the most difficult to get right. For transparency they talk about haze control, suggesting that it is not likely to be useful for packaging where transparency is required.
If the rate of oxygen transmission is high, the food gets oxidised in a very short period of time, – hours, not even days.
They say they produce the film using a solvent, but this would be a serious barrier/bottleneck in commercial production, and may also cause eco-toxicity.
Also the mechanical properties of films based on a solvent technology are generally poor.
The people concerned seem to have no experience of industrial production or scale up, and they are not even at the pilot plant stage yet.
It is claimed that “FlexSea has the potential to change the pattern of human consumption of plastic and therefore change the sustainability path of our planet,”
I really don’t think so.
NOT SO BIODEGRADABLE
I have been reading a paper by Royer S-J, Greco F, Kogler M, and Deheyn DD Not so biodegradable: Polylactic acid and cellulose/plastic blend textiles lack fast biodegradation in marine waters
They say “Referring to compostable plastics as biodegradable plastics is misleading as it may convey the perception of a material that degrades in the environment.”
“The resistance of plastic textiles to environmental degradation is of major concern as large portions of these materials reach the ocean. There, they persist for undefined amounts of time, possibly causing harm and toxicity to marine ecosystems.”
“However, to undergo rapid biodegradation, most compostable plastics require specific conditions that are achieved only in industrial settings. Thus, industrially compostable plastics might persist as pollutants under natural conditions.”
“Results show that polylactic acid, a so-called biodegradable plastic, does not degrade in the marine environment for over 428 days. .. In contrast, natural and regenerated cellulose fibers undergo complete biodegradation within approximately 35 days. Polylactic acid resists marine degradation for at least a year, and oil-based plastic/cellulose blends are a poor solution to mitigate plastic pollution.”
“Compostability does not imply environmental degradation, and appropriate disposal management is crucial for compostable plastics.
North Carolina Stops Cities Banning Plastic Bags
The North Carolina State legislature has prevented cities in the State from enacting policy or legislation that would “restrict, tax, charge a fee, prohibit or otherwise regulate the use, disposition, or sale of an auxiliary container.”
Opponents had argued that plastic bag bans are important because the bags are not biodegradable, but the remedy for this is to make them biodegradable with d2w technology See Why biodegradable?
Michael Stephen is a lawyer and was a member of the United Kingdom Parliament, where he served on the Environment Select Committee. When he left Parliament Symphony Environmental Technologies Plc. attracted his attention because of his interest in the environment. He is now Deputy Chairman of Symphony, which is listed on the AIM market of the London Stock Exchange, and is the founder and Chairman of the Biodegradable Plastics Association.
Earlier Postings in this Column
Interview with Michael Stephen
The opinions expressed here by Michael Stephen and other columnists are their own, not those of Bioplasticsnews.com