California’s attorney general on Thursday announced an investigation into the fossil fuel and petrochemical industries for allegedly overstating the role of recycling in curbing global plastic pollution and exacerbating the crisis.

Attorney Gen. Rob Bonta said his office has subpoenaed Exxon Mobil for information relating to the company’s alleged role in deceiving the public and worsening plastics pollution. The office didn’t specify what other companies it was investigating. Exxon did not immediately respond to a request for comment.

As state legislatures and local governments in the 1980s began considering bills restricting or banning plastic products, fossil fuel and petrochemical companies began an “aggressive” and “deceptive” campaign to persuade the public that they could mitigate the waste problem by recycling, which the industry knew wasn’t true, Bonta alleged in a news release.

“For more than half a century, the plastics industry has engaged in an aggressive campaign to deceive the public, perpetuating a myth that recycling can solve the plastics crisis,” Bonta said. “The truth is: The vast majority of plastic cannot be recycled.”

“This first-of-its-kind investigation will examine the fossil fuel industry’s role in creating and exacerbating the plastics pollution crisis – and what laws, if any, have been broken in the process,” Bonta said.

The world produces about 400 million tons of plastic waste each year, according to estimates from the United Nations. Plastics take hundreds of years to decompose, and the majority of plastics end up sitting in landfills or the ocean. The U.S. only recycles about 9% of its plastic, according to the Environmental Protection Agency.

Plastics are also set to drive nearly half of oil demand growth by mid-century, according to the International Energy Agency. Fossil fuel and petrochemical companies recently invested more than $200 billion to expand plastic production worldwide.

Environmental activist groups on Thursday applauded the state’s investigation of the fossil fuel industry.

“For too long, ExxonMobil and other corporate polluters have been allowed to mislead the public and harm people and the planet,” said Graham Forbes, plastics global campaign lead at Greenpeace USA. “The science has become crystal clear that we must move away from fossil fuels and throwaway plastic.”

— CNBC’s Katie Brigham contributed reporting