A Chinese government policy aimed at curbing imports of postconsumer plastic waste went into effect Jan. 1, leaving recyclers in the U.S. and elsewhere without a market for much of their plastic waste and causing material to pile up.

U.S. localities, particularly on the West Coast, have for many years shipped plastics collected in recycling programs to China. Low wages make China an ideal place for the labor-intensive sorting of plastic waste.

According to the U.S. Census Bureau and the U.S. International Trade Commission, China imported 776,000 metric tons of reclaimed plastic and 13 million metric tons of recycled paper from the U.S. in 2016. The total value was $2.3 billion.

China officially notified the World Trade Organization last summer that it would restrict the import of 24 types of waste. It explained that dirty and hazardous substances mixed with plastic and other waste pose a risk to health and the environment.

“This is going to be a huge shock,” says Douglas Woodring, the Hong Kong-based managing director of Ocean Recovery Alliance, a group that advocates for improved management of waste plastic. “Not many governments are currently equipped to deal with the huge backup this will create in their waste handling systems.”

Recyclers have been trying to prepare for the new rules, which build on an existing import control policy in China called National Sword, for the past few months. By October 2017, imports of waste polyethylene by Hong Kong, a major shipping point, were down by two-thirds compared with a year earlier.

Although the rules don’t ban the import of recycled plastics outright, they severely limit the practice by keeping the level of contaminants such as food residue and metals to no more than 0.5%.

“The proposed contamination standard is not practical to achieve, even at the most state-of-the-art facilities in North America,” Jeff Murray, international president of the Solid Waste Association of North America, said last month.

Alli Kingfisher, Washington state’s recycling coordinator, says materials recovery facilities, which process recyclables from municipalities, are trying to meet the new contamination threshold, hoping to get their plastics into China. But even though they are adding staff, throughput is slowing down, resulting in a pileup.

“They are still collecting as much material as normal, but the facilities are trying to improve quality,” she tells C&EN. “They just aren’t able to move as much material through.”

Some municipalities, particularly in rural parts of the state, have modified residential collection or even halted plastics recycling. However, she says, “most are trying to hold firm.”

In Oregon, the pileup has prompted a dozen collectors and processors to ask the state’s Department of Environmental Quality (DEQ) to let them dispose of recyclables in landfills, according to Julie Miller, a DEQ materials management official. “DEQ concurs that landfilling these materials on a temporary basis is an unfortunate but needed option,” she says.

In October, DEQ issued a bulletin instructing Oregonians to limit the amount of contamination in recycling streams. “Residents are encouraged to continue recycling, but to stop ‘wishful recycling,’ which is putting an item into a recycling container that doesn’t belong, wishing it will be recycled,” the agency said.

Despite the short-term repercussions, environmental activists see the new regulations as a long-term win for sustainability. Greenpeace officials in Asia say they will “force many countries to tackle the ‘out of sight, out of mind’ attitude we’ve developed towards waste.”

Exporting to China has distracted from sustainable waste management, Woodring argues. “The traders got in the way and provided an easy answer to the plastic waste problem,” he says.