Dear Not So Happy Recycler,
You are absolutely correct. Greasy cardboard, of any kind, must not be recycled. It only takes one greasy item to contaminate an entire batch. Cleanliness is not only important when recycling cardboard, but it is critical for everything that goes to recycling so that contamination doesn’t happen. When recycling cardboard boxes don’t forget to remove any packing materials, such as plastic, foam or Styrofoam peanuts. You do not need to flatten the boxes before recycling. Recycling cardboard important because it saves energy and it takes up so much space in the landfill. (Cardboard is the single largest component of municipal solid waste around the world.) To make new boxes out of recycled cardboard requires only 75% of the energy used to make new cardboard. Definitely better for our environment.