In the past, I've given you the lowdown on which plastics can be recycled [1] and told you 21 surprisingly recyclable things [2]. But aside from the question of pizza boxes [3], I haven't gotten around to telling you what not to recycle [4]. We all know that recycling is important, and San Francisco mayor Gavin Newsom even thinks those who fail to should be punished [5]. It's also pretty darn easy, especially if you've got a proper recycling bin [6] system. However, tossing trash into your recycling bins can really complicate things for your local recycling crew. You'll have to check your local recycling guidelines to see what restrictions apply in your neck of the woods, but to get a general idea of what is not allowed in recycling, .

This list, from San Francisco's recycling program [7], offers good guidelines on what not to put in your recycling bin:

• Batteries
• Electronics
• Ceramic dishes or cups
• Coat hangers
• Compostable plastics
• Food soiled paper (i.e. paper cups, plates, napkins, towels, takeout boxes. and greasy pizza boxes [8])
• Light bulbs
• Liquids
• Mirrors
• Plastic bags or plastic films
• Soy milk or juice boxes
• Styrofoam
• Waxed cardboard
• Window glass

Source [9]