Is it safe to compost in plastic?

When you get into the world of composting, worm farms, and everything else that makes gardening much, much easier you will need to create a compost bin. However, the journey to making your bin can take a long time, with many people not always aware of what they should, or could, be using as their bins. A common challenge faced by people being whether or not they can use plastic in their compost bin. 

You can and should be using plastic bins or bags as the main way in which you are composting, as the bins are safe to use and in the right environment can create the perfect composting environment. Plastic has been the main medium in which composting bins have been created for many years, and to date, there have been few ill effects. The only danger that some plastics pose to the process is degrading during the process and becoming unusable.

Understanding which plastics, you can use and how to use them is important to creating a successful compost bin. Doing so will ensure that your composting system does not fail before it has a chance to begin, with the best plastic bins allowing the worms and other creatures that do the composting to comfortably live. There are several bins on the market right now that is amazing, with several more already known for being amazing at composting. 

Which plastics are safe to compost in?

While most plastics will act the same, there are several that will waste away with your composting materials or become so droopy and useless that they cannot be effectively used in the sun. Further, smaller plastics meant for packaging or just being soft will not work, even as a lining for your composting, as they will usually become worn away quite fast. When it comes to the plastic bins that are used by people there are three types of plastic to consider.

Getting a bin that is dedicated to composting can be quite expensive, even if it does mean you can easily rest assured the plastic won’t degrade. However, the most common bins that are used will be those that are repurposed from other uses and allows you to easily ensure the plastic you no longer want does not end up in the ocean or landfills. 


This type of plastic is usually marked as 1, within the three arrows that you will always find on your plastics. These arrows with the numbering are what tells you exactly what type of plastic you are dealing with and have been universally standardized. PET plastic is most commonly used for foods and other products, which is why you will see them on the plastic containers you get your grapes and other produce in.

However, there are larger bins that will use this plastic as they were originally meant to be food-safe, to ensure that the plastic does not give off fumes to the foods. PET plastic is great, because it is similar to other plastics in how it resists heat but does not create toxic environments, which means that you can easily use them for composing without having to stress about the plastics killing your worms. 


This is the most common plastic-type in the world, recognizable by the number 2, and is easily the most versatile plastic you may find. Everything from the sprinkler system in your garden to the remote controls and dashboard of your car might be made out of HDPE. This extremely hardy plastic is loved for its ability to easily take almost any shape that we have needed and does not easily become toxic in everyday use.

Most likely the waste bins you have in your house, or that you can buy for cheap at a local hardware store will be made out of HDPE. This makes it the go-to plastic for compost bins because of the rigidity it has at low to high temperatures, and the extremely low cost of buying it. However, HDPE does not degrade easily and is almost impossible to fully recycle, so making sure that you do not create more waste from it is vital. 


Usually used as the alternative in food containers LDPE has the number of 4 and will be a much softer plastic than the other plastics you may find. These are the thin plastic containers that you may find your grapes held in, that are both flimsy and somehow annoyingly hard to cut. Rarely used for larger plastics LDPE does not offer the same level of rigidity as HDPE or PET does.

Further, you may find that compost bins made from LDPE have intricate structures to prevent the plastic from sagging when heated up. Placing these types of the bin in the sunlight can easily cause them to melt, losing shape, and losing almost all strength. If it gets too hot you may see these plastics bulge out under the weight of the internal mud and other things it contains. Many times, your LDPE bins will have to be specially made. 

Should you drill holes in your plastic compost bin?

This is a question that many faces, as they are aware that there should be holes in the compost bin but are not entirely sure how or where these holes must be. Indoor compost bins must have a layered system, a bin within a bin, with the internal bin having holes drilled throughout to allow for airflow. Bing that you are keeping outside must have holes along the side of the bin to allow fresh air to enter, and bad air to exit from the bin. 

Holes in the compost bin are important to allow several of the processes that you need to have healthy compost to be created. Usually, you can find that people are not always aware that not having a good flow of air can cause rancid mixtures of moisture and mold to grow in your compost. The worms that you need to create the compost can drown if there is too much moisture and can die if the temperatures are too high.

The holes in your compost bin are there to ensure that the natural process of breaking down plants, fibers, and everything else you are throwing in the compost goes as planned. Many times, you will see that not having the holes causes unwanted effects to take place, with a large majority of people finding that the composting process will fail because there is no air to breathe for the soil. 

What are the most common plastic compost bins?

While most people start making their compost bins from the spare plastic bin they may have found a second life for, there are more and more people that are actively looking for bins. However, as the need for people with bins has increased so too has the market of available bins, with many manufacturers quickly learning that they need to create special bins. This has to lead to a large amount of choice for those looking to create compost bins as the right one can be hard to choose.

The main challenge people seem to face is that they are not always aware that different types of composting environments require different types of bins. People living in hotter areas, requiring bins that won’t reach extreme temperatures, while people in cold areas need to ensure the compost does not freeze. Many times, you may be surprised to find that some of the more expensive bins are the small ones meant for your kitchen. 

  • ECO-2000 Plus: Coming in at a measly $29 this small bin has proven uniquely capable of being used for people that want to start the composting process in their home. Meant for the waste made from your daily cooking, such as chopped vegetables, coffee grounds, and other biomass it can create the perfect compost for your pot plants. Many times, you will find that these create just enough compost to keep smaller gardens of herbs well and truly thriving. 
  • VermiHut Plus 5: The first of the larger outside compost bins this elegantly designed bin assembles in layers, allowing you to easily reach each layer of compost without having to go digging. With a tap at the bottom to get rid of the inevitable buildup of water, you can control your compost, the worms in it, and how everything is growing with absolute ease. This bin does, however, cost a hefty $120 and will produce enough compost to help a mid-sized garden healthy.
  • SCD Probiotics: Sometimes you may live in a small apartment, or you may even find yourself not requiring a massive compost bin for all waste that you are making. This is when you should look into getting something like the SCD Probiotics that does not use any worms in its composting process. Coming in at only $54 it is affordable and will easily produce more than enough compost for any small herbal plants you may be growing. 
  • Good Ideas Compost Wizard: In the world of specialized compost makers the functionality of getting access to things easily is vital. The Good Ideas Compost Wizard Jr. is small enough to easily and comfortably be used on your back porch. On special at $130 from Walmart, it can easily allow you to create all the compost that you may need. Its round shape ensures that you can easily do one of the main processes required to create compost, turning it all over every few days. 
  • Aerobin 400 Exaco: The luxury version of composting that is perfectly insulated against the heat and the cold, the Aerobin 400 is a bit more pricey at $500. However, its built-in auto aeration system allows you to create all the compost you may need without having to turn it in. As your compost continues to grow you can easily access it as needed and spread it across your garden to ensure healthy plant growth. 

Where should you keep your plastic compost bins?

This is the most important part of using plastic bins as their location can greatly affect how well they work on growing your compost. The first mistake that people make is having their plastic bins placed somewhere sunny, which quickly causes the plastic to heat up to an extreme level. Your plastic compost bins should be placed somewhere they only get a few hours of the morning or late afternoon sun. 

This will ensure that neither the plastic nor the compost inside will reach temperatures that can cause damage. Plastic can be extremely resilient and most bins will not be damaged just by the sun shining on them, however, as most of them are black they can reach high temperatures. These high temperatures literally cook the compost on the inside, killing all bacterial growth and any of the worms that you may have placed in it. 

In hotter countries, you will find that the plastic becomes so hot that the bin can start to deform, usually because the weight of the compost inside is too much. To ensure that your compost is always working properly you will need to ensure that the bin is perfectly placed, ensuring that you do not lose control of the temperature of the bin. A good location will keep the bin at around 20 to 30 degrees Celsius throughout the day. 

What are the dangers of using plastic compost bins?

If you end up using the wrong type of plastic you will find that the bin will release fumes as it reacts with the water on the inside and the sun throughout the day. This is why you need to ensure that the plastic the bin is made from will not cause this reaction, with all purpose-built plastic compost bins already made from the right plastic.

If you use environmentally safe plastics then you will need to keep a close track of the age of your bin, with many people not always realizing that green plastics are made to dissolve. This can cause massive leaks or unexpected structural failures in your compost bin before the compost is even close to being done. Ensuring that you know how long the plastic should last will help you prevent the loss of your hard-worked compost and worms. 

With some normal plastics, you will find that they are not meant to be constantly exposed to both water and sunlight. This causes the plastic to rapidly deteriorate, which means that your bin will become microplastics that quickly become structurally weak. Most of the time these are the plastic bins that you may find are meant for office or kitchen use as they are purely meant to stay indoors at all times. 

What can you compost in plastic compost bins?

The best thing to compost in these bins will always be biomass, either shredded plants, and grass from your garden, or the fruits and vegetables from your kitchen. However, it should be noted that not everything will compost at the same time, which is why you should have more than simply one compost bin in your garden. 

Harder plant fibers should only be composted together with other harder plant fibers, which can take several months to be fully composted. While old food can be composted within a few days if your worms are healthy and active. This is why you will see that people are sorting through the stuff they throw in their compost heaps long before they throw everything in. 

The most dangerous things that can be added to the compost heap being unexpected acids from tomatoes, onions, or chilies. This way you should ensure that you have everything balanced, creating an environment where your worms will thrive, grow stronger, and multiply. With plant bins usually being the easiest to just leave and let the composting process begin. 


Despite what many people think it is entirely and completely safe to compost in plastic bins as the bins create sealed and controllable environments within which you know what will happen. Other materials used for compost bins can be too expensive, with many of them being either too permanent or not permanent enough. 

Just remember, if you have the space to dig a hole you can and should be creating a compost heap that works a lot more naturally than a plastic bin compost bin!

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