don't you P-O-L-L-U-T-E pollute the river, sky, or sea or else you're gonna get what you deserve

How much cheese is too much? And what about the shampoo caps? Do I have to flatten the cardboard? And really, why no broken glass? These are the kinds of questions that freeze well-meaning recyclers in confusion between the blue bin and the trash can.

To get to the bottom of these mysteries, I checked in with the head of Los Angeles’s Solid Resource Citywide Recycling Division, Neil Guglielmo, who may be one of the few people in America who actually knows how much cheese is too much. Paper and cardboard, Neil says, do in fact need to be clean. “If it had a sandwich on it and you knock off the crumbs, that’s OK. If it had stuck-on lasagna, it can’t be recovered.” Ditto the pizza box.” Both will end up in a landfill. As for unflattened cardboard, it will get recycled, but it hogs a lot of unnecessary space in the truck. And broken glass? It shatters into pieces that are impossible to sort.

The trouble with that oozing Aveda bottle is that “it all goes into a big truck, and that smushes this nasty stuff” with the nice clean paper. Neil suggests that you rinse out the bottle once or twice and replace the cap. (Yes, to caps!) And yes, a bottle with a small lake of rosemary-mint shampoo in the bottom will still be recycled, but before that happens, the government has to use our taxes to wash it for you.

GOOD | Ask An Expert: What Happens When Non-recyclables End Up in the Blue Bin?