With the rising interest in compostable plastic as an environmental and sustainable alternative option, it’s important to understand how to dispose of compostable plastic such as trash bags. Many people are confused between biodegradable and compostable as well industrial composting facilities and home composters versus worm farms. Many ask if it ok to put compostable plastic bags in your home compost or worm farm?
You can dispose of compostable plastic, including bags, in an industrial composting facility or home composter. Compostable plastics are manufactured to break down rapidly in these environments but are much quicker in a controlled environment such as an industrial composting facility. A home composter or worm farm is not ideal for large amounts of material and is less controlled, meaning it can take longer to break down.
How Does Composting Work?
Compostable bags are essentially made from bioplastics which are made especially to breakdown in a home composter or industrial composting facility. A typical plastic bag may take thousands of years to breakdown, however a compostable bag can cut this time to only six months or less.
Compostable plastics are made to return to the environment when they breakdown and also to provide nutrients to that environment. These are made from organic materials and able to be decomposed quickly with a home or industrial composter.
Compostable plastics also don’t leave behind or emit toxic chemicals when disposed of correctly. However, if you don’t dispose of compostable plastic correctly and drop it in landfill, it will take a long time to decompose like traditional plastic. There are biodegradable plastics that, unlike compostable, are able to decompose quickly in landfill environments.
What Is Compost?
It’s important to understand what compost actually is when it comes to a home composter, worm farm or industrial composting facility. Compost is really just decomposed organic material. It can be anything from kitchen scraps, plants, twigs, egg shells, coffee grounds, worms or leaves.
Compost is used in the garden or soil to improve the quality of the soil and make it a better environment for planting and growing. Compostable plastic is then broken down by microbes or fungi in the environment over time. The timeframe depends on several factors such as moisture or temperature – both of which are strongly controlled for optimal decomposition in an industrial composting facility.
When composted through biowaste collection, the plastics can decompose much quicker. This is due to the microbe-rich environment contained in an industrial composter which assists the plastic to breakdown faster. This includes four main components: organic matter, oxygen, bacteria and moisture.
The Composting Process
The size of the pile, types of materials are also key factors in the time it can take to breakdown the plastic. For larger amounts of compostable materials, an industrial composting facility is much more effective. Larger amounts in a home composter or worm farm will take much longer to breakdown.
Essentially, the steps to composting include:
- Choosing where to dispose of your compostable materials i.e. worm farm/home composter or industrial composting facility
- Layers in the composter are to be alternated (different matter, layered)
- Layers added until the composter is full
- Maintain composter – home composting must be added to and turned, whereas, industrial composters are maintained with controls
- Harvest compost.
Home Composting Or Industrial Composting Facility?
Compostable plastic is best broken down in an industrial composter as that’s what it is designed for rather than landfill. These composters are set up perfectly with the right temperature, moisture levels, air and other important factors for decomposition.
This ensures that the materials breakdown the quickest and most effective ways possible. It’s also ideal for large amounts of material and resulting compost, whereas a home composter is useful for small amounts.
You will have a similar resulting compost in a home composter or worm farm, however, without controlled temperature, moisture levels, oxygen etc, a home composter will take longer to breakdown and may not be as efficient or effective.
Home composters and worm farms also can’t take anything containing meat, fish or dairy as they will not only smell, but attract insects and vermin. Typically, in the right environment, a compostable bag will take around 90 days to decompose in a compost bin. So, it is ok to put compostable plastic bags in your home compost or worm farm.
How Can You Use A Worm Farm ?
Worm farms can be used for compostable materials, however, there are some additional restrictions that a home composter does not have. Essentially, you want to feed the worms as they speed up the composting process.
You cannot put anything citrus – such as orange peels or anything with juice – into a worm farm. This is due to the acid levels which will impact the soil. Garlic, onions and other smelly spices or vegetables, purely for the acid levels and smell. Anything with grease, meat, bone, oil, butter, stock etc. This can impact soil levels and attract vermin or insects. In a worm farm, you want the worms fed and alive.
This means that you need to feed them non-acidic fruit and vegetable scraps, grainy bread, pasta, coffee or tea. You also need to limit your disposal in the worm farm as worms can be overfed and the bin will start to smell. It’s best to feed them every two-to-three days and you will potentially see an entire feeding gone in one-to-two weeks.
The composting bedding in the worm farm also needs to be at an optimal level – not too wet or too dry, or too hot or too cold. You also need to be careful to remove the compost regularly. Essentially, worm farms are more work than traditional home composters.
What Materials Are Recommended To Compost?
Many of the materials needed and appropriate for compost have been listed in this article, but the highlights are organic materials and compostable plastics, including leaves, food scraps and grass clippings.
Some appropriate materials to add to your home composter or an industrial composting facility:
- Food waste including vegetable or food scraps
- Coffee grounds or tea
- Breads, pasta or cereals
- Grass clippings, twigs or leaves
- Manure or dry cat or dog food
- Newspaper (black and white) or printer paper.
All of these materials are ideal organic materials that can be broken down in the right environment such as a home composter, worm farm (excluding acids) or industrial home composting facility.
How Long Does Compostable Plastic Take To Breakdown In A Compost?
When disposing of compostable plastics, it takes around 90 days minimum, in the correct environment. As our compostable plastics home experiment found, within six weeks of decomposing in a home composter, the plastic bag was already in small pieces.
Often, the guiding principle for decomposition is three-to-six months depending on your method, other materials being composted and the amount of waste to be composted. In an industrial composting facility, which is controlled for optimal breakdown, it is closer to the three months.
A home composter will be between three-to-six months depending on how much you are hoping to decompose and how you maintain your composter or worm farm. If you don’t dispose of your compostable plastic correctly, it will take as long as traditional plastic which can be centuries.
Is It True, That Home Composting Compostable Trash Bag Releases Harmful Gases?
The appeal of compostable plastics is their non-toxicity and ability to decompose back into organic material such as water, biomass or carbon dioxide when disposed of correctly. They can release methane which is a potent greenhouse gas if they are disposed of in landfill.
Composting is anaerobic process that actually reduces or prevents the release of methane during breakdown, meaning that home composting is a great option for those wanting to reduce their greenhouse gas emissions.
Methane is not produced because the methane-producing microbes are not active when oxygen is present. The practice of composting maximizes aerobic conditions which are the most effective for reducing such emissions.
Disposing of traditional plastics in your home composting bin or worm farm will leach toxic chemicals and negatively impact your composting ability.
Is It Beneficial To Compost Plastic At All?
It is extremely beneficial and environmentally friendly to compost compostable plastics due to the breakdown of materials into organic matter and reduction of negative emissions. Provided you are disposing of compostable plastics in the correct ways – home composter, industrial composting facility or worm farm – and following correct processes, you are making a sustainable and ethical choice.
By choosing to compost the correct plastics, you are lessening your contribution to landfill, creating useful compost for your own or large soil projects and disposing of other materials such as food scraps in a sustainable and safe manner.
However, if compostable plastic is NOT disposed of correctly or a home compost or worm farm is not maintained correctly, your efforts may be in vain. This could be due to harmful disposal methods, increasing greenhouse emissions, leaching toxic chemicals (all for incorrect disposal) or impacting your soil or worms with the wrong materials or processes.
When making your decisions on whether you can put compostable plastic bags in your home compost or worm farm or the use of compostable materials such as trash bags, or how to dispose of these, it’s important to consider your usage and how you will dispose of the items. Although you can choose the most organic option in compostable, if you simply throw the item in the bin then your choice is neither sustainable nor environmentally friendly.
Consider whether or not you have access to a composter or whether you will likely dispose of the item in general waste. If you have a composter or worm farm, ensure you understand which materials belong in each and how to maintain them.
Also consider how you will use the resulting compost and how you will maintain your composter or worm farm for the most effective outcomes that will assist your garden or land. If you will most likely dispose of in an industrial composting facility, be aware of how you will access such a facility
Investigate your local biomass composting facilities and how you can dispose of your compostable plastics effectively.