On the bottom of most plastic containers I’ve noticed a triangle-shaped symbol indicating that the container is recyclable. In the middle of this symbol is a number ranging from one to six or higher. I know these numbers have something to do with the classification of plastic products, but what is the difference between a one and two or six in terms of recycling? Finally, why do most recycling centers take type one or two containers but not three through six? Where are we supposed to take these other products so they can be recycled? I want to recycle, but it is hard to do with all this confusion. –J.R. Richards, Sterling, Virginia

Things are more confused than you realize. The main problem is that the triangle symbol, more commonly known as the “chasing arrows” symbol, doesn’t indicate recyclability, contrary to wide belief. The number just indicates the type of plastic. As I’ve written before, the numbers range from one to seven; one through six are the most commonly used plastic resins, and seven is miscellaneous. It’s important to keep the types separate when recycling because they have different melting points and other characteristics, and if you throw them all into the pot together you wind up with unusable glop.

Although it’s technically possible to recycle most plastics, recycling types three through seven is rare, because using virgin material is cheaper. Things are better with type one (polyethylene terephthalate or PET, used for pop bottles) and type two (high-density polyethylene or HDPE, used for milk and detergent bottles). Twenty-eight percent of type one is recycled, including 41 percent of plastic pop bottles, because type one containers are usually easy to sort and clean, the stuff can be used to make a lot of products, and virgin type one feedstock is relatively expensive. Type two is less attractive (for one thing, it’s hard to get rid of the smell in old milk bottles); still, the bottles are big and easy to sort out of the waste stream. About 11 percent of type two plastic is recycled.

Types three through seven you might as well throw away. Recycling rates for these materials are around 1 to 2 percent. Some recycling operations won’t even take types one and two, arguing that plastic items of whatever type are so bulky in proportion to their value that it’s a waste of fuel to send out a truck to haul them away. The recycling rate for all plastic packaging is a dismal 7 percent, compared with 53 percent for aluminum.

Some environmentalists think it’s deceptive to use the chasing-arrows recycling symbol on plastic packaging, because it fools people like you into thinking the product is likely to be recycled when the overwhelming probability is it won’t (with the exception of bottles). In 1993 and ’94 representatives of the National Recycling Coalition and the Society of the Plastics Industry attempted to work out an improved symbol that would address this objection. The effort went aground on–get this–the new symbol’s shape. The final proposal called for replacing the chasing arrows with an ordinary triangle and adding a letter to the numbers (e.g., 2B) to indicate various grades within each type of plastic as a sorting aid. SPI’s board approved the plan, but NRC’s refused, saying the triangle and the recycling symbol looked too much alike and suggesting a square or rectangle instead. SPI claimed a rectangle would increase industry retooling costs 400 percent–a triangle would let plastics companies modify existing molds, hammering the chasing arrows into a triangle with an engraving tool, whereas a rectangle would mean making new molds at great expense. In the absence of an agreement the old system will remain in place indefinitely, since 39 states now require it and only a united front on the part of recyclers and plastics companies would persuade state legislatures to enact a change.

So what are you supposed to do? Given the difficulty of recycling plastic, a lot of environmentalists say it’s best to avoid disposable plastic when possible. Of the plastic you do buy, recycle types one and two, first rinsing all items carefully. Above all, don’t mix in types three through seven (unless your local recycler specifically says they’re OK), plastic without a code, or random garbage. If you do, some poor stiff will have to sort through the muck.

Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.