What's the difference between compostable and biodegradable packaging?
Compostable versus degradable. Here we are providing the terms and definitions frequently used in marketing communications so we can better identify these materials, ensuring these products are disposed of correctly.
What is the difference between biodegradable and compostable packaging?
Transformation by means of organic recycling (composting) requires a material or product to be biodegradable. Biodegradation is a chemical process in which materials are metabolised to CO2, water, and biomass with the help of microorganisms. The process depends on various factors.
Compostability is a characteristic of a product, packaging or associated component that allows it to biodegrade under specific conditions (e.g. a certain temperature, timeframe, etc). These specific conditions are described in standards, such as the EN 13432 standard and the Australian Standard on Commercial Composting AS4736. Materials and products complying with these standards can be certified and labelled accordingly. For further clarification:
Degradable
Capable of being degraded. The term means any material capable of being decomposed chemically or biologically. Most materials degrade over time. Plastic degrades to microplastic, for example.
Biodegradable
An extension of degrading. Materials with the ability to be broken down into non-harmful substances through living micro-organisms, a natural process. The time frame taken for materials with this capacity varies depending on the perishability of the material itself.
Compostable
Often wrongly considered to be the same as biodegradability, compostable materials require specific conditions in order to decompose back to their natural elements.
READ: Why is compostable packaging excluded from kerbside food scrap collections?
Compostability of materials according to the European Standard EN 13432
Compostable products are designed for organic recycling. A variety of techniques are used to compost large volumes of organic matter at high temperatures. Usually, in industrial composting facilities, temperatures in the composting heaps range between 50°C and 60°C. There are three main techniques used in industrial composting: windrow, in-vessel, and aerated static pile composting.
Compostable packaging that is tested and certified according to European standards for industrial composting, EN 13432 (for packaging) or EN 14995 (for plastic materials in general), fulfil the technical criteria for treatment in industrial composting facilities. These plants provide controlled conditions—controlled temperatures, humidity, aeration and subsequent bacterial activity.
The criteria for the industrial compostability of packaging are set out in the European standard EN 13432. EN 13432 requires compostable products to
— disintegrate after 12 weeks
— and completely biodegrade after six months.
That means 90 per cent or more of the plastic material will have been converted to CO2. The remaining share is converted into water and biomass – i.e. valuable compost. Materials and products complying with this standard can be certified and labelled accordingly.
READ: What are bioplastics?
Biodegradability is a prerequisite to compostability
To be recovered for organic recycling (composting) a material or product needs to be biodegradable.
Biodegradability can be confirmed by certification to various internationally recognised standards such as EN 13432, ASTM D6400, or in Australia, AS 4736-2006, where biodegradability in commercial composting facilities is required. Biodegradability is not affected by the source of the raw material, so fossil-based raw materials can be biodegradable, just as some renewable raw materials can be.
Compostability is characteristic of a material packaging product that allows it to biodegrade under specific conditions (e.g. a certain temperature, timeframe, etc) as described in standards. A material is considered compostable when, under defined conditions in a composting system the material is:
1) entirely transformed to minerals and biomass within a specified time period and
2) its decay results in compost, a natural fertiliser that can help to restore soils, control weeds, retain ground moisture, and reduce soil erosion.
The compostability of a product is certified through certification bodies to either industrial or home compostability standards. The main certification bodies are:
* TÜV Austria
* DIN CERTCO
* Biodegradable Products Institute (BPI)
* Australasian Bioplastics Association (ABA)
EN 13432 is the reference standard for all certification bodies. The European Norm about compostability of packaging (EN 13432) requires (besides a clear and detailed description of the product) 4 tests:
-
biodegradation (chemical breakdown)
-
disintegration (physical breakdown)
-
ecotoxicity (assess negative effect on plants)
-
heavy metal content
READ: Compostable materials in the real world: Scion x WasteMINZ
Composting and circular economy
Composting is part of the waste-to-value system, and it is where we must focus our efforts if we want to reach the ambitious targets set by our government that commits Aotearoa, New Zealand, to becoming a low-emissions, low-waste circular economy by 2050.
Project Drawdown ran the numbers and calculated that establishing new compost facilities costs USD61 billion less for a 36-year period than establishing new landfills.
Operating compost facilities costs more than operating landfills but this also means employment opportunities in addition to reducing biogenic methane and waste landfilled. Select composters accept compostable packaging through contracted collections, however, without policies to improve the recovery of compostable materials, this packaging will continue to be landfilled.
Published in 2023, the report, 'Unpacking Labelling and Design: U.S. Consumer Perception of Compostable Packaging' provides a starting point for mandating design guidelines that would work towards unifying the industry and overcoming the limitations of recovery. Findings from the study and our observations.
The study tested design variables that included logos, white versus natural, inclusion or absence of green striping, embossing versus printing and the use of the commonplace phrase ‘made from plants’, which found:
Up to 49% of respondents had difficulty distinguishing between the terms “compostable” and “biodegradable”, leading to improper disposal.
Solution: Central policies that govern packaging design and labelling are enforced. Problematic look-a-like products are banned. Run advertising campaigns, as suggested in the 2019 report, ‘Rethinking plastics in Aotearoa,’ to educate the public on compostable plastics.
Many consumers do not know where to dispose of compostable packaging at its end of life. Home composters would place any compostable item in their backyard compost.
Solution: Current ‘guidance’ is legislated. Vague claims of biodegradability are not valid in accordance with Commerce Commission guidance. Brands are required to state whether the packaging is industrial or home compostable but without a legal framework, free-riders continue to benefit.
The disjointed approach between local and state-level policies and regulations that govern packaging design and labelling limits the recovery of compostable packaging.
Solution: Policymakers, brands and retailers align to harmonise the policies, regulations (including national compost input guidelines) and packaging design to recover and transform compostable materials while minimising contamination.
The report points out that in the U.S., composting infrastructure is in the middle of transitioning from processing just yard waste to accepting more types of inputs, including post-consumer food waste and compostable packaging.
What would it take to see compostable packaging accepted in kerbside collections?
It would be possible to recover compostable packaging at far greater rates than today, not to mention food waste, if policy supported it. We see a similar scenario in Aotearoa New Zealand.
We see a future where compostable packaging is correctly disposed of, and readily accepted, recovered and processed by composters, adding value to their businesses. This will require a regulatory framework and legislation that bans packaging with problematic additives and requires certification compliance, where compostable packaging is easily identified utilising one of four certification logos. This future is possible.
We’ve been here for over a decade, developing and supplying industry-leading, certified compostable packaging, working towards accelerating the circular economy in Aotearoa, New Zealand. We’re proud to serve our clients by providing compostable packaging that is soil-safe and designed for circularity.
If your business is still using plastic, use the links below to explore our service further. For custom branding enquiries, please email us at hello@ecoware.co.nz.
