How to Recycle our Home Compostable Bags – Summary
If you receive your chocolates in a clear bag with a ‘Home compostable’ sticker here’s the short summary of how to recycle it :-
- Your bag can be put in your home Compost heap and will degrade and completely disappear in a few weeks. Many local authorities have a subsidised composter purchase scheme. If you have garden space why not start!
- Your bag can be put in your Food Waste collection as it is home compostable. But you may wish to double check locally.
- In theory your bag may be put in your Garden Waste collection but please check locally. Some authorities such as Wiltshire list compostable bags as not suitable.
- The bag is made from Plants not Plastic – so please DON’T put it in Plastic Recycling it will contaminate the recycling stream.
If you don’t have any of the above collections then black bag waste is a last resort. This is the worst option as it doesn’t put the bag to good use completing the circle from plant to soil.
If you want to know why we we’ve removed plastic from our packaging please read our post on plastic pollution
We’ll explain more about the plant based materials we’re using below…
We set up our own garden compost heap and test our home compostable bags against plastic bags over three months – Plants v Plastic
Plants vs Plastic – Does Plant based packaging work?
We’ve talked about the problems of plastic pollution and recycling and this moves us on to the question – what are the alternatives?
Firstly there are some terminologies that you may have encountered…
– Biodegradable
– Industrially or Commercially Compostable
– Home compostable
Biodegradable
Biodegradability of a material means that a substance can be decomposed by biological processes – that is, by living microorganisms for example bacteria and fungi.
Ideally, the product is completely converted into water, CO2, and biomass during that process.
Biodegradation doesn’t require any human intervention and is a natural process. How quickly or slowly that degradation takes place isn’t specified in the definition of “biodegradable”.
So the rate of degradation depends on environmental conditions, including temperature, humidity, and availability of oxygen (although biodegradation can occur with and without oxygen). Essentially all materials are biodegradable to some extent.
There are two different types of biodegradable plastic:
Vegetable-based plastics, which are also loosely known as “bioplastics” or “compostable plastics”, are tested in accordance with ASTM D6400 or EN13432 as to their ability to biodegrade under conditions found in industrial composting or biogas facilities.
Oxo-biodegradable plastics—which are made from polymers such as polyethylene (PE), polypropylene (PP), or polystyrene (PS) contain a prodegradant catalyst—often a salt of manganese or iron. Oxo-biodegradable plastic will degrade in the presence of oxygen much more quickly than ordinary plastic.
In theory the plastic material has then been converted into small-chain organic chemicals that are no longer plastic and are biodegradable by bacteria. The timescale for complete biodegradation in the open environment is much shorter than for “conventional” plastics, which in normal environments are very slow to biodegrade.
It is important to distinguish between “oxo-degradable” plastics, which fragment but do not biodegrade except over a very long time, and “oxo-biodegradable” plastics, which degrade and then biodegrade.
Industrially or Commercially Compostable
Composting is a human controlled biodegradation process usually used to improve the soil. In commercial composting higher temperatures and controlled microbe conditions are used in industrial plants.
Under EU standard EN 13432 a material can be considered compostable if…
– At least 90% biodegrades within 6 months
– There are no more than 1% additives which must be non-toxic and have no negative effects on plant growth
Kerb side Garden Waste collections are usually commercially composted.
Home Compostable
Home compostable packaging can be put into your own garden compost heap. Garden compost heaps reach lower temperatures than commercial compost heaps and conditions are less controlled. Hence not all industrially compostable materials will degrade in a garden compost heap. So materials need to be certified as Home Compostable.
Currently there are few bodies that certify for Home Compostability – TUV Austria is the only organisation we know of – http://www.tuv-at.be/home/
Summary
So all compostable packaging is biodegradable, but not all biodegradable packaging is home compostable.
You could say that at least in terms of recycling the order is…
Best
– Home Compostable
– Commercially Compostable
– Biodegradable
Worst
At Lick the Spoon we are using Home Compostables where we need a food contact safe barrier, or in many cases Food contact safe cardboard.
Types of Kerbside Waste Collection
Garden Waste
When the garden waste arrives at the composting site any material that is not compostable is removed, the remaining waste is then shredded and then laid out in a long pile to decompose, usually in the open air.
The process at a composting site is similar to that that takes place in home compost bin, but is actively managed to speed up the process. However, due to the amount of material the temperature reached is a lot higher than in a normal household compost bin. Temperature can reach up to 60°C. This higher temperature means that the enzymes and bacteria are quickly put to work resulting in finished compost in just a few weeks.
The material is turned frequently to provide much needed oxygen to micro organisms that help decompose the material. High temperatures kill off any harmful microbes, weeds and plant diseases.
The final part of the process involves screening the compost to remove any remaining contaminants and to grade the material for various end uses. Any compost that is still oversized or hasn’t decomposed enough, can then be put back through the process until it has composted down sufficiently.
The whole process takes between 8 and 16 weeks, depending on the final use for the compost.
A potential issue with recycling compostable and home compostable materials in Garden Waste is that as they are relatively new, and are not dissimilar to plastic in appearance they may be screened out even though they are suitable for composting. Currently our own Wiltshire Garden Waste collections don’t allow compostable materials for example.
https://www.recyclenow.com/recycling-knowledge/how-is-it-recycled/garden-waste
Food Waste Collections
Many councils now collect food waste. Depending on your council food waste can be recycled in different ways.
In-vessel composting – the council facility will mix food waste with garden waste, shred it and then compost it in an enclosed system for around 2-4 weeks at temperatures up to 70°C speed ensuring any harmful microbes are killed off. The material is then left outside to mature for a further 1-3 months with regular turning and checks to ensure quality before going on to be used as soil conditioner.
Anaerobic Digestion uses microorganisms to break down food waste, animal manure, slurries and energy crops in the absence of oxygen, inside an enclosed system. As it breaks down it gives off methane, which is collected and converted into biogas and used to generate electricity, heat or transport fuels. It also creates a nutrient-rich digestate that can be used as a fertiliser for agriculture and in land regeneration.
Food Waste collections allow the use of compostable bags to line the caddy so your bags can be placed in Food Waste in a reasonable proportion.
From 2023 it is likely that DEFRA will roll out a National food waste collection scheme.
What do Lick the Spoon Use?
All of the materials we’re using that we put the Compostable sticker on are Home Compostable and are based on the plant based brand name ‘Natureflex’ film. You can see the Natureflex certifications below. We’ve also tested them in our own home compost heap.
Natureflex Certification
NatureFlex™ films are certified in accordance with the Industrial composting standards, EN13432 and ASTM D6400, by Din Certco and the BPI. In addition, all standard NatureFlex™ films are suitable for home composting and have been certified to ‘OK Compost Home’ by TÜV Austria.
INDUSTRIAL COMPOSTABILITY
The key elements of the EN 13432 test programme include:
Biodegradation
A minimum 90% biodegradation versus a control sample in a maximum of six months.
For NatureFlex™ films this is achieved in less than 45 days.
Disintegration
A pilot composting test ensures that the material physically breaks down within three months.
Material Characterisation
Includes heavy metal testing and determination of the volatile solid content.
Ecotoxicity
Compost from the disintegration test is used to ensure that the components have no adverse effects on the plant growth.
HOME COMPOSTABILITY
The test programmes for EN 13432 and ASTM D6400 confirm the suitability of a material for composting in an industrial composting plant. In this situation, the conditions are optimised for biodegradation at a temperature of ca. 58ºC.
In many countries however, consumers actively compost their garden waste at home, either in compost bins or heaps, eliminating the need for collection. These processes are more variable due to lower temperatures (rarely more than 2 to 3oC above ambient temperature) at less optimised conditions. Under these conditions, certain compostable materials do not exhibit sufficient biodegradation.
NatureFlex™ films have been tested and approved to the OK Compost Home standard, which repeats the EN 13432 test protocol for biodegradation and disintegration at ambient temperatures, albeit over a longer time frame. They can, therefore, be successfully composted in a home composting environment and typically break down in just a few weeks.
SOIL AND WASTE WATER BIODEGRADATION
The NatureFlex™ NE30 grade has been tested to the MITI aqueous biodegradation test (ISO 14851) which demonstrates that it will also break down in waste water and in soil, as well as under home composting conditions.
ANAEROBIC DIGESTION
All families of NatureFlex™ films have been tested to ISO 15985 (High solids anaerobic digestion test) at 52ºC. After 15 days all the films, exceeded the test requirements, reaching a similar level of biodegradation to the reference.
MARINE BIODEGRADATION
The majority of NatureFlex™ films have successfully been screened for biodegradation and disintegration in seawater, according to ASTM D 7801-05 and ASTM D 6691-09.
End of Natureflex Certification
Controversy?
Compostable and Home compostable materials are very new and consequently local authority waste collections may have difficulties identifying them as non-plastic materials.
This issue was raised in The Times recently…
From the Times June 7 2019
“Shoppers are being misled by disposable cutlery, packaging and nappies that are labelled as “compostable” but will not break down for years, scientists have warned.
Some high-street chains have been offering a range of compostable alternatives as consumers turn away from single-use plastics.
However, most of these products are only guaranteed to decompose in industrial composting plants in conditions that cannot be reproduced in a garden compost heap. Most local authorities do not have systems for collecting and dealing with them.
This means that the majority are destined for landfill sites, where they may not decompose for years, said Professor Mark Miodownik, a materials scientist at University College London. “The public really need to know that when something says it’s compostable, it is not going to disappear as soon as you drop it and it may not actually be good for the environment,” he told the Cheltenham Science Festival.”
So are Home Compostable bags better than plastic?
So potentially the best way of dealing with Home Compostable packaging is to put it in your own Garden Compost heap and put it back to the soil. However not everybody will have a compost heap. Nonetheless, in our opinion at the present time Home Compostable materials such as Natureflex are a huge leap forward. If they end up in the wrong place they will degrade rapidly with minimal harm to the environment.
Whereas the current state of Plastic recycling and shipping plastic waste abroad is an environmental disaster.
But it is a rapidly changing and complex field – one of Imperfect Sustainability.
UN Sustainable Development goal 12 sums this up well…
UN Sustainable Development goal 12 looks at Responsible Production and consumption – How can I help as a business?
“It’s in businesses’ interest to find new solutions that enable sustainable consumption and production patterns. A better understanding of environmental and social impacts of products and services is needed, both of product life cycles and how these are affected by use within lifestyles. Identifying “hot spots” within the value chain where interventions have the greatest potential to improve the environmental and social impact of the system as a whole is a crucial first step. Businesses can also use their innovative power to design solutions that can both enable and inspire individuals to lead more sustainable lifestyles, reducing impacts and improving well-being. “
Home Composting Scheme
Food waste collection schemes in the UK vary depending on the local authority.
In Wiltshire where Lick the Spoon are based there is no Food Waste collection scheme. But, if you have space there is a subsidised Home Composter available http://www.wiltshire.gov.uk/reducing-your-waste-and-composting
This is the composter we have used in our trials and we’ve found it to be incredibly satisfying to see Food and Garden Waste break down into useful compost. It’s reduced the the amount of black bag waste to almost nothing on a two weekly collection.