Eggs are one of the most consumed foods in North America, and that also means that we generate a lot of egg cartons. While recycling items is always preferable to throwing things away, the best forms of recycling is when we find new uses for our old items.
You can compost egg cartons that are made from paperboard or cardboard, as these materials are made from wood pulp or recycled paper and are biodegradable. The carton can be torn into small pieces and placed directly into a compost heap or compost pile, where it will count as part of your ‘brown’ material for your C:N ratio.
If you want your compost pile to be totally organic, then you should only use ink-free parts of the cardboard/recycled paper egg carton. This is because the inks used for printing egg cartons are colored. And colored inks contain trace elements of heavy metals.
In this article I will go through the different types of egg cartons that you may encounter and which ones can be composted, as well as other good practical uses for egg cartons.
Types of Egg Cartons
In general you may encounter 3 types of egg cartons at the grocery store.
Egg carton recycling / composting reference table
|Egg Carton Type||Paperboard Egg Cartons||Plastic Egg Cartons||Foam / Styrofoam egg cartons|
|Material||Wood pulp / Recycled Paper||Polyethylene Terephthalate Plastic (PET)||Plastic beads|
|Can it be composted?||Yes. Tear into small pieces||No||No|
|Can it be recycled||Yes||Yes||Sometimes (depends on waste company)|
Paperboard / Cardboard Egg Cartons
Egg cartons that are manufactured from wood pulp or recycled paper are known as paperboard egg cartons. They have been in use since the 1980’s, when the environmentalist movement gained steam. To make them, recycled paper or cardboard is blended with water and made into a slurry. This is then pressed onto a mold, and voila – the egg carton is made.
Should you compost paperboard egg cartons with ink?
While some sources will state that inks are generally soy based and safe to compost, studies have repeatedly found that colored inks will often contain trace elements of heavy metals, even in food packaging. If you would like to read more on this topic, I suggest you read this section of our guide to risks of composting paper/cardboard.
Now, the amount of heavy metal from the ink on a single egg carton would be quite small. Even if you composted with egg cartons (ink & all) for years it would probably take a very long time for the amount of heavy metals to build up to dangerous levels in your garden. None the less, if you can reasonably avoid this risk, you should do so as a ‘best practice’.
In my own compost piles, I only compost the bottom half of the egg cartons to avoid any addition of heavy metals from the ink being transferred to my compost, and then to my garden soil. I do this because it is a reasonable amount (low) of effort to eliminate a risk.
Plastic egg cartons
The plastic egg cartons you can encounter at the store are made by a lightweight clear plastic known as PET (Polyethylene Terephthalate). The plastic is heated and pressed into molds to form the carton.
Plastic egg cartons are recyclable, which will reduce landfill waste. Recycled plastic uses less energy to be reused as opposed to making new. But they are not biodegradable, so should not be composted.
Styrofoam / foam egg cartons
Foam egg cartons have been around since the 1950’s. They are manufactured by taking small beads of polystyrene and heating them, and then pressing them into a mold. Egg cartons made from Styrofoam are not biodegradable nor compostable.
Depending on your location or waste company that services your neighborhood, you may be able to recycle Styrofoam. You will need to check with the waste company, as recycling polystyrene is more complex and expensive than other common materials. 
Due to the fact that foam egg cartons are not biodegradable coupled with the difficulties recycling them, it is better to purchase egg cartons made from more earth-friendly materials, such as paperboard.
How to compost egg cartons
To compost egg cartons, simply tear up or cut up paperboard egg cartons into small pieces and add them directly to your compost pile or compost heap. It will count as brown, carbon rich material.
The smaller the pieces of egg carton, the better it will mix in your pile, and thus breakdown faster. This is important as the paperboard egg cartons are high in lignin which is slower to decompose than other brown materials.
Can you compost egg cartons with egg spilled on them?
Sometimes bits of egg accidentally spill, or an egg gets stuck to the carton. You can compost egg cartons that have small amounts of egg residue on them. While standard composting practice says not to compost proteins, I have found over the years that it is ok if you have a hot pile, or the amount is quite small. Problems may arise if your pile isn’t hot or there is a lot of egg, as your pile may now attract animals or hatch flies.
However, if there is egg residue or egg on a carton, it can no longer be recycled and should be thrown out in the trash.
Egg cartons made from paperboard are an excellent source of brown material for a compost pile. If eggs are a standard part of your household’s diet, then you can slowly accumulate them overtime, so you always have a supply on-hand. It is easy to process and stockpile, making it available to most anyone.
 – “Allowed Mulches on Organic Farms and the Future of Biodegradable Mulch” USDA National Organic Program. Accessed 24MAR2022.
 – Kirwan, M. J. “Paper and paperboard packaging.” Food and beverage packaging technology (2011): 213-250.
 – Elmas, Gulnur Mertoglu, and Gamze Çınar. “Toxic metals in paper and paperboard food packagings.” BioResources 13.4 (2018): 7560-7580. Accessed 25MAR2022
- Bartolome, Leian, et al. “Recent developments in the chemical recycling of PET.” Material recycling-trends and perspectives 406 (2012): 576-596.
- Maharana, T., Yuvraj Singh Negi, and Bikash Mohanty. “Recycling of polystyrene.” Polymer-Plastics Technology and Engineering 46.7 (2007): 729-736. Accessed 04AUG2022.
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