The rate rose to 21.6 percent in 2004, up from 19.6 percent the previous year, and the amount of PET bottles collected for recycling jumped dramatically to a little more than 1 billion pounds, according to a Sept. 29 report from the National Association for PET Container Resources.

The Sonoma, Calif.-based trade group pointed to a number of factors for the reversal of fortunes for PET recycling: increased demand, especially in the carpet industry; more pressure from government in California to use recycled plastic in containers; and a better competitive position with virgin materials.

"The biggest news is the amount of PET collected jumped significantly, which is a good sign, and it looks like we´re going to be able to maintain that," said NAPCOR Chairman Gerry Claes. "The other side of the coin is that demand for PET continues to grow."

Environmental groups said the increased recycling rate should be put in perspective: It´s still well below the PET industry´s high-water mark of 39.7 percent in 1995, and it means four of five containers were thrown out, said Jenny Gitlitz, a senior research associate with the Container Recycling Institute in Arlington, Va.