Dear Recyclebank: Should I crush plastic bottles when recycling, to reduce their volume? –Michelle S.

Dear Michelle: First of all, consider ways in which you could reuse or upcycle your plastic bottles instead of sending them to the recycle right away. If you need some ideas, check these out. If you don't have any immediate uses for the plastic bottles you do have, then whether or not you should flatten them depends on the kind of recycling program you participate in.

If your community uses single-stream recycling you should probably avoid crushing your bottles, as flattened bottles can accidentally end up in the paper stream while being sorted at your Material Recovery Facility (MRF). In a study performed to find ways to improve recyclability, it was found that retaining a three-dimensional form helps containers be properly sorted.

If your community uses multi-stream recycling on the other hand, wherein you sort materials at home, it may be acceptable. So should you flatten your bottles in this case? You don't have too, but you most likely can. Your hauler takes your recyclables from your house to a transfer station and then to a material recovery facility where they are sorted, crushed and baled, and then shipped to a recycling center. By crushing your plastic bottles at home you’ll be able to fit more inside your bin, and, assuming the truck your hauler uses isn’t a compactor, the truck will be able to hold more recyclables also, making transportation more efficient. When you crush your bottles at home you’ll give the machinery a bit of a break, plus it’s a fun way to blow off some steam.

Don’t forget that crushing your plastic bottles is about being more efficient, not less so, so be aware of your haulers plastic cap rules. If your recycling program explicitly tells you to remove the cap before recycling your plastic bottle, make sure you do. Crushing the bottle and screwing on the cap is fine for MRFs that are designed to handle caps on plastic bottles, however, it will cause contamination for facilities that aren't equipped to process capped bottles. Know before you throw.

The same goes for aluminum cans. If you put all of your recyclables in the same bin you shouldn’t crush your cans, as it is easier for equipment to sort intact cans. If you separate your recyclables at home, go ahead and crush your cans too.

It is always best to get confirmation from the source. What’s most important is that you follow the guidelines put in place by your MRF, so find out from your hauler or city if it would help or hinder their operations for you to crush your bottles at home.

SOURCES: Association of Plastic Recyclers