Do the Scratch Test
Shiny cardboard boxes can be recycled, while wax coated takeout boxes cannot. To identify a wax coated box, scratch the cardboard and see if the wax comes off. If the wax comes off, throw it out.
No Grease or Food
Cardboard takeout containers cannot be recycled with other cardboard if they are contaminated with food or grease. Food traces can contaminate the recycling process. Alternatively, you can tear off the soiled portions and recycle the rest.
Compost Dirty Containers
Soiled cardboard takeout containers can be composted in your backyard. Find out more about how to compost cardboard from Gardening Know How.