A Comparison of the Weltrade Landfill Biodegradable Additive v Oxo-Degradable v PLA

Due to the wide range of possibilities, many producers, brand owners, and regulatory authorities are drowning in a sea of contradictory and perplexing information on various technologies. Compostable, degradable, and biodegradable materials are sometimes grouped together, adding to the difficulty. However, these materials differ greatly in terms of the science underlying the technologies, sourcing, physical characteristics, and end-of-life possibilities. This study will assess the three main options that manufacturers have in terms of their environmental impact, scientific merit, and commercial feasibility.

The Science

The Weltrade independently verified additive is specially formulated to create “biodegradable” polymers without sacrificing the beneficial properties of the primary polymer including recyclability. This type of technology is fairly new to the polymer market, yet well-tested and validated. To accelerate the biodegradation of traditional resins, The Weltrade additive is added at 1% during the plastic moulding process. It is a combination of specific nutrients and organic compounds which, once discarded, allows microbial action to colonise on and around the plastic and completely metabolise the polymer. The end result being inert humus (biomass) and biogas (anaerobic) or Co2 (aerobic).

Oxo-degradable additives produce a “degradable” polymer as an alternative to the degradable choices that do leave microplastics. Oxo-degradable additives have been available on the market for a while, and as a result, many different formulations are used to influence the product’s disintegration. The visible plastic is broken down into tiny particles by these additives, which employ metal ions to create weak links in the polymer chain that oxidise to form brittle plastic. Products that are oxo-degradable degrade when exposed to oxygen and light. No publicly available data has demonstrated that oxo-degradable materials genuinely “biodegrade” once they have broken down to the microscopic level. As a result, there is concern over the presence of heavy metals and chemicals (such as plastic polymers, cobalt, cadmium, and other harmful leftovers) in the ground and oceans.

Another typical mistake relates to PLA (polylactic acid). A commercially available compostable polymer called PLA is made from renewable resources like sugarcane or corn starch. Despite being well-known for more than a century, PLA has only recently attracted commercial attention due to its commercial compostability and renewable source.

Due to the decreased physical qualities and higher price compared to conventional polymers, the applications have been restricted.

Sourcing

A lot of research is presently being done on sourcing, where it is possible to make common plastics from renewable feedstocks like algae and sugar cane. The significance of the source takes care of two problems: the scarcity of fossil fuels and the rising carbon production from them. Plastics that address sourcing often require large supplies of fossil fuel during processing and often negate the carbon benefit. It is also important to note that renewable is not synonymous with sustainable. Sourcing from renewable materials does not address end-of-life and pollution issues. Sourcing and disposal are separate and important issues.

Weltrade Packaging’s landfill biodegradable additive is sourced from fossil fuel-based materials making it readily available, inexpensive, and easily integrates into existing fossil fuel-based resins to create a traditional polymer that is both sustainable and biodegradable.

Oxo-degradable additives are added to conventional polymers made from petroleum and are generally derived from metals and salts.

The materials used to make PLA are sustainable. Since this is the main advantage touted by producers of PLA materials, it is critical to carefully consider this claim. In terms of the environment, PLA goods necessitate the allocation of precious food resources (land, food items, etc.) that could be utilised for food production. According to numerous investigations, fossil fuels used in the processing of plant starch for plastics are more environmentally damaging than fossil fuels used in the production of conventional polymers. There is also significant controversy over the use of GMO (genetically modified) materials as the primary feedstock for PLA.

Physical Properties and Shelf Life

Weltrade Packaging’s Landfill biodegradable additive is used similarly to that of a colourant, adding them during the melt phase of manufacturing. Products made using our additive maintain the same physical properties as the base polymer. Specific shelf-life will depend on the product application and is the same as that found in standard polymers. Applications with our landfill biodegradable additive will not biodegrade on the shelf, warehouse or storage facility, they must be placed in a high microbial environment (landfill environment) for biodegradation to take place.

Both Oxo-degradable and PLA products have limited shelf life and other handling issues. These are important facts to consider when using either Oxo-degradable or PLA packaging for your product.

Oxo-degradable is also introduced to the polymer much like a colourant. The cost is very low for these types of additives; however, the product shelf-life for oxo-degradable is between 2 to 6 months. Some of the 2nd generation oxo-degradable products claim the shelf-life has been increased to 6 months to 2 years (if the environment is right). The process of degradation of oxo-biodegradable begins immediately after manufacturing and will accelerate when exposed to heat, light or stress. Anti-oxidants and UV inhibitors are placed in the product to help counteract this degradation and short shelf-life. It is important to note that other manufacturing issues may arise from the use of oxo-degradables.

Products made from PLA or starch are more challenging to process and frequently need new machinery or modifications to existing production processes to accommodate the low processing temperatures needed. Nowadays, the shelf life of PLA products is between two and four months. These products must be kept in a temperature-controlled environment since they respond poorly to heat and moisture. It is important to highlight that the use of PLA may lead to additional manufacturing and product difficulties. For instance, PLA cannot be coloured using conventional colourants and has a poorer oxygen barrier and lower impact resistance than PET.

Biodegradability 

The term “biodegradable” is a generic one that occasionally gives the impression that littering is acceptable. The value of biodegradation comes into play when that performance coincides with the managed environment the application will/should be properly discarded into.  No matter the performance, if the application ends up in the open/unmanaged environment, that return value is lost and the application becomes an environmental detriment.

Applications using Weltrade Packaging Landfill biodegradable additive are biodegradable in anaerobic (no oxygen, no light), and aerobic (with oxygen) environments, this includes common landfills. When these materials are placed in a microbial environment the additive attracts specific microbes which digest the entire polymer, thus leaving behind inert humus (soil) and biogases.

From an environmental perspective, there are a number of issues that arise from using oxo-degradable and PLA (plastics made from plant starch) products. Both oxo-degradable and PLA products require an environment with oxygen, UV, and heat in order to begin breaking down, these conditions are NOT often found in landfills.

Oxo-degradable is not “biodegradable”, they are simply “degradable”. It is important to understand that degradation is simply the loss of physical properties and does not necessarily include the actual breakdown of the polymer chain or monomer. Oxo-degradable additives have been on the market for a number of years and as such there are a number of different versions used which will affect the breakdown of the products. These additives create weak links in the polymer chain which oxidize to create brittle plastic reducing the visible plastic. Oxo-degradable products do not completely biodegrade which results in leaving behind harmful heavy metals and chemicals (plastic polymers, Cobalt, Cadmium and other toxic residue) in the ground and oceans. As a requirement, ALL oxo-degradable additives require oxygen, heat and UV in order to break down. These conditions are NOT found in landfills and will result in the products existing for many, many years.

For PLA goods to breakdown, a very stringent environment is needed. These goods cannot be disposed of in landfills, on the sides of roads, or in the ocean; they must be placed in commercial composting facilities. The goods must be placed in a specialised compost facility that regulates the precise heat, oxygen, and moisture conditions in order to do professional composting. PLA must first go through a chemical breakdown, which results from exposure to high temperatures—the kind is only seen in commercial composting facilities—before it can begin to disintegrate. There are currently no commercial composting facilities that welcome PLA plastic products.

Recycling

The ability to recycle is an important aspect when choosing an earth-friendly polymer solution. There are billions and billions of bottles, film, and other packaging applications being dumped in landfills throughout the world, and recycling is one way to postpone the pollution problem. The majority of recycled plastics are either PET or PE bottles and products that contaminate these polymers should not be considered environmentally sound solutions.

Weltrade Packaging Landfill Biodegradable products are completely recyclable and should be comingled with existing plastics recycling. Scientific data and independent recyclers support that these products will not contaminate recycle streams as the material used does not impact the polymer chain in any way.

Products that are oxo-degradable bind to the polymer chain and produce “weak links” that oxidise when exposed to oxygen and UV light. Oxo-degradable materials weaken the polymer chain and have a short shelf life, which makes it exceedingly unlikely that they can be successfully recycled unless they are heavily diluted with standard polymers.

PLA is recyclable but not within the current recycling infrastructure; most recyclers have trouble with PLA due to PLA visually looking like PET. With PLA’s low melting temperature compared to PET, PLA is considered a contaminant and has caused some batches of recycled PET plastic to be unusable.

Conclusion 

Less than 13% of all plastics will be recycled and over 87% of plastics will have a customary disposal environment of a landfill. It is almost impossible for any kind of plastics today to enter commercial composting facilities.

A sound corporate sustainability strategy will have to address the elephant in the room and come to terms with the fact that the vast majority of the plastic waste that their products and product packaging produces will end up disposed of in a landfill. This is true even if a company chooses to stamp a recycle symbol on their product or to ask that the product be recycled. Being recyclable does not mean a product is recycled.

Most plastic products on the market today cannot attract enough (if any) microbial activity to begin breaking down the polymer’s molecular structure, thus leaving the process of reclamation to light, heat, mechanical stress and moisture. Products such as PLA and oxo-degradable materials claim to be biodegradable but are in fact only commercially compostable (unable to degrade in a landfill environment), or the product simply breaks down into smaller pieces (plastic flakes).

Our additive is a landfill biodegradable additive that is proven in both anaerobic and aerobic environments to biodegrade from the breakdown of naturally available microbes. Products enhanced with our landfill biodegradable additives are designed to biodegrade in landfill environments leaving behind only inert humus (soil) and biogases. An important characteristic of Weltrade Packaging Landfill biodegradable additive is that its ability to maintain the same physical properties (shelf life, texture, appearance, oxygen transfer rate, etc.) as traditional plastics and the ability to be recycled alongside traditional polymers. PLA and oxo-degradable products have a limited shelf life, reduced physical properties and contaminate the plastic recycling stream.

The Weltrade Packaging Landfill Biodegradable Additive, to sum up, is a combination of organic materials (FDA GRAS) that are added into standard polymers at 1% and produce an application with the same physical properties and shelf-life as your traditional polymer, while also retaining recyclability and adding landfill biodegradable from the natural breakdown of microbes. This is a popular technology for brands because they can still work with the same resins that they are familiar with and have the added benefit that the plastic application will not remain in the environment longer than the people who made it. The solution also contributes to the production of clean energy in landfills that convert gases to energy.

This is why we encourage our trading partners to send the message “Please do not litter” or “Discard properly” because the application is “designed for renewable energy recovery” or “landfill gas-to-energy” (along with eliminating plastic pollution and microplastics, lowering GHG emissions, and reducing the carbon footprint). It’s not that it’s just biodegradable and the consumer no longer needs to be concerned about properly handling waste; that’s where biodegradable performance gets convoluted.

Appendix A: A comparison between Weltrade Packaging Landfill Biodegradable additive and other polymers on the market.

Table 1.0 – Comparison between ours and other technologies in the market.

*Time requirement for biodegradation is dependent on a number of environmental factors such as temperature, moisture, Ph level and the quantity and quality of microorganisms – degradation results may vary.

Authored Steve Welsh – Weltrade Packaging, involved in the packaging industry 29 years, Sustainable packaging specialist. Researched and independently tested to ASTM D5526 confirm Anerobic Biodegration of Plastic Materials Under Accelerated Landfill Conditions. Independently tested for heavy metals and food safety compliance.