The truth about Composting Compostable Plastic Bags

Nowadays, many more people are switching to compostable products, namely compostable bags as an sustainable alternative to single-use plastic bags.

What is Compostable Plastic Bag?

Compostable bags are essentially made from bioplastics which are made especially to breakdown in a home composter or industrial composting facility.

Compostable trash bag

How Does Composting Work?

While a typical plastic bag may take thousands of years to breakdown, a compostable bag can cut this time to only six months or less.

Compostable plastics are made from organic materials and able to be decomposed quickly with a home or industrial composter. They will return to the environment when they breakdown and also to provide nutrients to that environment.

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.

It's ok to put compostable plastic bags in your home compost or worm farm?

You can dispose of compostable plastic 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 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.

In conclusion, if 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.

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.