Recycling's Dirty Dozen: No Crushing Containers! (But You Should Flatten Cardboard Boxes)

Recycling’s Dirty Dozen: No Crushing Containers! (But You Should Flatten Cardboard Boxes)

  • Editor’s Note: This article is written by Julia Linares, AmeriCorps member with the Chicago-area Greenest Region Corps and a fellow for Cook County’s Department of Environment and Sustainability, along with Kane County Recycling Coordinator Jennifer Jarland, both of whom are members of the Illinois Task Force for Recycling Contamination Solutions. The article is part of a year-long a series on the “Dirty Dozen” of recycling — the 12 items that should NOT go in your recycling cart. Got local questions or concerns? Contact Jarland at 630-208-3841 or

Although flattening containers — like cartons, plastic bottles and cans — may save room in your recycling bin, please refrain from crushing these items, as it makes them harder to sort correctly in single-stream recycling systems.

However, you can still flatten cardboard and corrugated boxes! (See more information below on the benefits of flattening boxes.)

Single Stream Recycling


If you put all your recyclables into one bin for curbside collection, then your recyclables are part of a single stream recycling system.

It makes it easy for residents because you can throw all the paper and containers into one bin. So the burden of sorting is on the materials recovery facility, and we can help to make that process as efficient as possible by following guidelines like this one.

Why Can’t They Sort Flattened Containers?

If a container is in an unfamiliar shape, like a crushed can or water bottle, then it may be mistaken as a different material and sorted incorrectly.

Containers are sorted by human sorters as well as machines that identify containers by their shape. There are optical sorters that identify the resin types of plastic and air blows the plastic containers into different areas accordingly.

If a container is crushed it is harder for the machines to identify and makes it nearly impossible for the air to blow it where it needs to go.

For this reason, do not flatten plastic or metal containers.

Keep containers (like water bottles, juice jugs, milk cartons, and soda cans) in their original shape for the best chance of proper sorting.

And remember the exception to this rule is that cardboard and corrugated boxes do need to be flattened.

ALWAYS Flatten Cardboard, Corrugated Boxes

While boxes have a high national recycling rate, with over 88% of corrugated boxes recycled in 2017 (U.S. Environmental Protection Agency), we can still aim to increase efficiency while recycling boxes. One easy way: always flatten your boxes.

Benefits of breaking down cardboard and corrugated boxes:

  • Gives you more room in your recycling bin.
  • Limits recyclables getting lodged in your bin during collection.
  • Reduces space in transport to recycling facility.
  • Increases productivity in recycling process that uses wheeled screens to sort the cardboard out at the front end of the sorting process. If it is flat, it is easily and correctly sorted.

Read The ‘Dirty Dozen’ Series!