George W. Bailey / Shutterstock.com Paperboard Recycling Bin George W. Bailey / Shutterstock.com In San Luis Obispo County all paperboard can be placed in your recycling Cereal Liners Are Not Recyclable Cereal box liners are generally made of HDPE (High Density Polyethylene), which is not recyclable. Find out what you can do with cereal box liners.