So back to sorting out those plastics. A good place to begin is with the American Chemistry Council’s handy chart on plastic types.

The chart shows that there are seven types of plastics, each with its own tensile strength, flexibility, resistance to acids, opacity, that sort of thing. Each was developed to serve certain product needs, and each has specific post-consumer uses.

For example, # 1 plastic (Polethylene Terephthalate or PET or PETE) is clear, shatter resistant and waterproof, which makes it suitable for soft drink bottles, food jars for peanut butter and jelly and oven film. Cleaned and recycled, it can be spun into fibers to make fiberfill and carpet yarns. You’ve heard of polyester.

Number 1 plastic is very different than, say, # 3 plastic (PVC), which is used to make sturdy piping, window frames, rigid packaging and decking and railing. (You’ve probably heard that PVC is controversial. It requires chlorine to manufacture and releases dioxin when burned – but only if its burned in a certain way, Krebs said, which it almost never is. Municipal burning of PVC does not produce dioxin, he said. In terms of recycling, the pertinent factoid to know is that PVC can contaminate an otherwise “clean” load of #1 plastic.)

The second step to getting your scout badge in plastic recycling is to know that at this point in history there are just two plastic types that you really need to remember and absolutely attempt to reclaim for recycling: Plastic # 1 (PET) and # 2 (high density polyethylene or HDPE).

These two plastic varieties – which are used to make soda, water and juice bottles (#1’s) and milk jugs, shampoo, dish and laundry detergent containers (#2’s) comprise the vast majority of plastics recycling in North America, Ettafagh says. So, stick to those and you’ll do no harm. (And while you’re at it, throw out the caps because they’re often made of a different plastic.)