Researchers earlier this year said were surprised to find atmospheric levels of a banned blowing agent used in the production of spray polyurethane foam were much higher than expected. All they could deduce was the source was somewhere in East Asia.

Now, a Washington-based organization called the Environmental Investigative Agency says in a new report that the CFC-11 blowing agent is coming from Chinese factories making rigid polyurethane foam insulation. Use of the banned chemical, which damages the atmosphere’s ozone layer as well as contributes to global warming, was said to be “widespread and pervasive.”

“EIA has evidence from eighteen companies in ten provinces that they use CFC-11,” the report’s introduction reads. “Detailed discussions with company executives make clear that these are not isolated incidents but instead represent common practice across the industry.”

The rise in emissions that began in 2012 was detailed in a study published in the journal Nature in May.

Investigators also said there is “significant potential” for illegal trade in the chemical, raising the possibility that foam could be made with the chemical in other countries. The EIA called on both China and parties that signed the Montreal Protocol banning the chemical to take immediate action to investigate and halt the practice.

CFC-11 is cheaper and more effective

Blowing agents produce the gas bubbles in foam insulation that make polyurethane such an effective thermal insulator. But scientists linked a decline in the ozone layer to the production of CFC-11 (trichlorofluoromethane), and an international pact called the Montreal Protocol called for phasing it and certain other chemicals out of production.

Scientists began detecting elevated levels of CFC-11 after 2012, and now the EIA says it knows why Chinese manufacturers like it so much: It works better and costs less than the blowing agents that were supposed to replace it.

Acting on the report in Nature, EIA investigators found several possible sellers of CFC-11, some of which were advertising online. EIA sources later contacted a number of concerns in China’s growing polyurethane market. Of 21 companies that responded to their inquiry, 18 confirmed their use of the chemical to make polyurethane (PU) foam.

“Producers and traders of PU foam blowing agent told EIA sources that the majority of China’s foam industry continues to use CFC-11 due to its better quality and lower price,” the report said.

One seller of CFC-11 told the EIA that while alternatives have been developed, their manufacturers force buyers to use other ingredients as well. He called it a “price fixing system, very different from what you can get from us pricewise.” Some companies apparently keep drums of a more environmentally friendly alternative, HCFC-141b, on hand “just for show” when inspectors show up.

Enforcement efforts to shut down companies making the chemical illegally “seem to have had limited impact.” One company said that as much as 90% of its foam production used CFC-11.

The EIA’s Avipsa Mahapatra told The Guardian that investigators were “dumbfounded” when the companies admitting using CFC-11, adding, “These companies, again and again, told us everybody else does this.”