Bmz Bio-Foam® - More Info

BMZ Bio-Foam® - More Info

We have taken care to provide consumers with the most information possible to understand the enhanced biodegradation process of our footwear bases and what we are trying to achieve (does not include the straps as they can be ground-up and re-used several times).

We are acutely aware of companies all over the world ‘green-washing’ with buzzwords such as ‘eco’, ‘green’ and ‘environmentally friendly’. These are generally used as collective terms as many sustainable initiatives can become rather complex.

It also seems that businesses all over the world are selling products ‘made from recycled’ something or other. It is important to know what happens to that product AFTER it has been re-purposed, re-used, thrown away and long forgotten about (end of life).

For example, years ago, we trialed flip flops with the sole made from recycled tyres. This is not something new. Companies were doing this 20 years ago. However, while this sounds great and keeps those tyres out of landfill for 12 months or so, the result is the same. Once discarded, the flip flops (including the recycled tyre sole) ends up in landfill or our oceans for an extended period of time. We want to be better! Information is provided below by suppliers, independent laboratories, University research papers and the ACCC. 

Lengthy research, cost, development and independent testing has led us to come across certain organic additives used in the material make-up to enhance the biodegradation of plastic products in a biologically active landfill (not available in all areas). ASTM D5511 tests (representing biologically active landfills) carried out for durations ranging from 1 to 12 months, on a broad category of product containing the additive have shown excellent biodegradation rates. It is important to note that biodegradation will begin and will continue leading to significant bio-assimilation, shortening the time span the plastic would have occupied the landfill space from hundreds of years to several years.

 Independent ASTM D5511 tests, representing biologically active landfills, have shown 33.9% bio-degradation of our Bmz Bio-Foam® within 153 days.

Please note: We will continue to publish biodegradation results here.



The Mechanism of Biodegradation using BMZ Bio-Foam®

Plastics (or polymers) are made of long molecular chains of organic molecules called monomers. Polymers do not exist naturally, and most are designed to be incredibly stable – as a result they do not easily biodegrade and will last in the environment for centuries and possibly forever. They are air-tight and water-tight.

Bio-foam is made with a brand of organic additives which enhance the biodegradation of plastic products, through a series of chemical and biological processes in a biologically active landfill. It allows the plastic to be consumed (as a food energy source) by the microbes.



In a microbe-rich environment (like a landfill), the additive attracts microbes and these microbes start colonizing on the surface of the plastic. The enzymes secreted by the microbes render the plastic hydrophilic (water-loving). As a result, a film (bio-film) which is rich in microbes and moisture forms on and adheres to the surface of the plastic. Microbes then hydrolyze the plastic using secreted enzymes and water.


Aggressive accumulation of water expands the plastic matrix and gives the microbes access to the entire polymer matrix. The most likely points of attack on hydrocarbon polymers are at or near the chain ends.


The microbes break down the large “synthetic” polymer chains into simpler “organic” monomers, thus allowing for the consumption of the polymer matrix. In the process, they secrete certain signaling molecules that other microbes can detect. This signaling process, called quorum sensing, is an invitation to others to come join the feast. Volatile organic fatty acids, hydrogen, and carbon dioxide are formed in the initial stages.


Different types of microbes join the feast. Each one uses different elements of the polymer and/or various by-products of the intermediate biological reactions as a food source, breaking down the complex polymer chains. Certain enzymes (from microbes) begin reducing the complex polymer branching while others look for bulkier chains similar to fatty acids. A syntrophic environment containing diverse species of microbes is established to continue the complex chemical steps of biodegradation. Throughout this process, microbes continue to multiply through quorum sensing.


During the biodegradation process the molecular weight of the plastic material is reduced and the molecular weight distribution is broadened. The molecular weight reduction has occurred on chains of all lengths in the original plastic material matrix. As individual polymer chains biodegrade, biomass (humus), and biogases (methane and carbon dioxide) are left behind. The carbon dioxide produced in the intermediate steps is being consumed in each subsequent step; therefore, not much is left at the end. The methane can then be captured for energy use.

“Around 130 landfills in Australia are capturing methane and using it to generate electricity. Based on installed power generation capacity and the amount of waste received, Australia’s largest landfills use 20-30% of the potential methane in waste for electricity generation.” – (Source below)

Read more about ‘the importance of landfill gas recovery in Australia’ here -



Are your products the same as starch or sugar-based plastics (PLA, PHA, PHB, etc.)?
No. Our footwear is not similar to corn or sugar based plastics in their properties, how they function, or how they biodegrade.


Is the product made from oxo-degradable plastic?
No. Oxo-degradable plastics require oxygen and UV light or heat to initiate degradation and thus will not biodegrade in landfills. Our product does not require either UV light or oxygen to biodegrade and will biodegrade at any depth in landfills. Oxo-degradable plastics break down in to smaller components called 'microplastics' and are actually terrible for the environment.


Is the organic additive FDA compliant?
Yes. Our additive is FDA-compliant for contact with food in polystyrene (PS), polyolefin (all polyethylenes and polypropylenes) and polyethylene terephthalate (PET) applications. This doesn't really apply to Boomerangz. Don't eat your thongs.


Do your products made with the organic additive have a limited shelf life?
No. Unlike both PLA and Oxo products, the additive has a very long shelf life and products made with it, have the same shelf life as they would have had without it.


Will these thong's breakdown and start biodegrading while I'm wearing them?
No. For the product to breakdown it needs to attract oleophilic bacteria (oil-eating bacteria) that are present in landfills. The active microbes in food or dairy products or lawn care products are not oleophilic and not the “super” colony microbes you find in landfills, composting sites or waste water sludge plants.


How long does it take these products to biodegrade in landfills?
This will depend on the conditions of the landfill and the thickness and composition of the product. The average landfill is a very good environment for biodegradation because it is warm, moist, and full of soil micro-organisms and food waste that cause the micro-organisms to eat the plastic. ASTM D5511 tests (representing biologically active landfills) carried out for durations ranging from 1 to 12 months, on a broad category of product containing the additive have shown excellent biodegradation rates. It is important to note that biodegradation will begin and will continue leading to significant bio-assimilation, shortening the time span the product would have occupied the landfill space from hundreds of years to several years.


Are any of the ingredients in the additive harmful to people or to the environment?
No. The additive is 100% organic and is in compliance with FDA standards for contact with food. (again, doesn't really apply to us... don't eat your flip flops!).


Here you can find an excerpts from the Australian Competition and Consumer Commission:

Environmentally friendly, environmentally safe, planet safe or green are vague claims that could mislead consumers into thinking that a product causes no, or minimal, harm to the environment in its production, usage and disposal. In reality, almost all products have some adverse impact on the environment at some stage in their life cycle. Do not use these claims unless they can be supported through verifiable testing methods.

Biodegradable —no single understanding of or definition for ‘biodegradable’ exists. The term itself may convey a range of meanings to consumers and should not be used indiscriminately. As with any unclear or uncertain term, extra care should be taken to avoid misleading consumers and breaching the Trade Practices Act.

100% biodegradable or 100% degradable—this descriptor is an absolute claim that usually means ‘entirely’ or ‘totally’. Describing a product as ‘100% biodegradable’ or 100% degradable indicates that the whole of the product will biodegrade or degrade in the same way and over the same time period—and that’s not likely.

Please note: Boomerangz Footwear do NOT claim that the footwear is 100% biodegradable. We use an independent laboratory for biodegradation testing using the ASTM testing standards.


Australia has no mandatory standard on biodegradability or degradability. However, the voluntary Australian standard (AS) 4736–2006, Biodegradable plastics—Biodegradable plastics suitable for composting and other microbial treatment has stringent requirements for the time frame in which a product must break down in a commercial composting environment, its toxicity and the amount of organic material it contains. Various voluntary standards and tests for biodegradability exist in overseas jurisdictions, along with an emerging view of best practice in this area, and referring to these may help consumers and businesses to assess claims. See, for example, AS/NZS ISO 14021:2000, Environmental labels and declarations—Self declared environmental claims, and European (EN 13432) and American (ASTM 6400) biodegradability standards.

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The information and publications available on the ACCC site are broad guides to aspects of legislation and the work of the ACCC. They are solely intended to provide a general understanding of the subject matter and to help you assess whether you need more detailed information.

Web content is not legal advice
The material on the ACCC site is not and should not be regarded as legal advice. Users should seek their own legal advice where appropriate. Every effort is made to ensure that the material is accurate and up to date. However, we do not guarantee or warrant the accuracy, completeness, or currency of the information provided.

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