Every Earth Day finds us thinking of the 3 Rs:  Recycle, Reuse, and....? Oh, well, never mind. But we do want to, need to, remember the plastics code. We know that some plastics are more recyclable than others. Some can leach toxic chemicals into our water and food--not to mention, when dumped in landfills, into our earth and water. How to tell good and bad plastics apart?

The answer lies with the number within the triangle made of chasing arrows. Which numbers signify the safest and most recyclable plastic? Simple:  It's as easy as 1,2, wait, STOP! Not, ever, 3. Then skip to 4, 5. Not 6 and, sometimes, not 7. But sometimes, yes 7.

Really, it is simple! We'll try a list and then you'll see.

#1, PET or PETE (polyethylene terephthalate):  easily recycled, not found to leach. Used in water, juice and soft drink bottles. 

#2, HDPE (high-density polyethylene): easily recycled, not found to leach. Used in milk jugs, detergent and shampoo bottles. Soon to be in a new Nalgene bottle.

#3, PVC or Vinyl (polyvinyl chloride):  not recyclable; soft PVC can leach toxic phthalates. Used in some cling wraps, children's toys, fashion accessories, rain gear, detergent and spray bottles.

#4:  LDPE (low-density polyethylene):  recyclable at recycling centers; not found to leach. Used in most plastic shopping bags, cling wraps, some baby bottles and reusable drink & food containers.

#5:  PP (polypropylene):  recyclable in some curbside programs, not found to leach. Used in some baby bottles, most yogurt and deli takeout containers, Tupperware- and Rubbermaid-type reusable food and drink containers.

#6:  PS (polystyrene):  recyclable in some curbside programs, can leach styrene, a neurotoxin. Used in rigid foam drink cups, takeout food containers, egg containers, some plastic cutlery.

#7:  It's a mixed bag! This code applies to all other plastics, notably PC, or Polycarbonate, which Nalgene is discontinuing in its popular Lexan sports bottles because it can leach the suspected hormone disupting chemical, bisphenol-A. Polycarbonate also doesn't recycle.

But #7 also includes the relatively benign new copolyester Tritan plastic, which Nalgene is substituting for PC in its new Everyday line; Camelbak also makes sports bottles with Tritan.

Adding to the confusion, the burgeoning crop of bioplastics falls under code #7, as well. These include PLA, or Polyactide, made from plants, especially corn. As a material, it's certainly renewable and hence greener than petroleum, with which all the above plastics are made. Ant it's used with increasing frequency in water bottles, bags, supermarket takeout containers and other packaging.

At the moment, PLA is not easily recyclable, but it can technically be recycled with other, conventional plastics so long as it comprises only 5 percent of the batch.  Hmm. Some brave recycling programs, apparently, are game. Most commonly, PLA can be composted in industrial-strength composters, at high heat (not advised for your kitchen bin, but a good option for universities, hospitals and other large institutions). PLA will decompose, slowly, eventually, in a compost heap or landfill (heaven forbid), where it can release methane, another greenhouse gas.

For more info, see the Institute for Agriculture and Trade Policy's Smart Plastics Guide .

And, we remembered the last 'R,' reduce! When it comes to acquiring new items made of plastics, whether they're derived from petroleum or food crops, that seems a good idea all around. 

Story by Mindy Pennybacker. This article originally appeared in Plenty in April 2008.

Copyright Environ Press 2008

Ways to tell good plastics from bad ones
Some plastics are more recyclable than others.