To clean or not to clean? The answer hinges on the economics of food residue.
The answer, unfortunately for the lazy recyclers amongst us, is yes.
It turns out that your oily, salad-dressing covered take-out box is still perfectly salvageable—but it's worth up to 30 percent less than a cleaner container. Butler discovers that:
Municipal facilities first sort recycling by type (paper, several kinds of plastic, tin, etc.), and then by quality. Workers separate clean recyclables from soiled ones, into bales. "If the bale is lower quality, there is less revenue coming back into the system from the sale of recyclables, which helps pay for the program," says [Robert] Reed [spokesperson for Recology, the company that runs San Francisco's recycling program].\n
So, while you shouldn't let grease marks or tomato juice stop you from recycling your food containers, if you can clean them, do it! You'll be helping to make recycling more economical (and thus attractive) for your city and your fellow taxpayers.