A coalition of conservation groups delivered a petition Tuesday in San Francisco demanding the U.S. Environmental Protection Agency stop approving petrochemical projects that produce millions of tons of plastic and waft greenhouse gases into the air.

The petition, signed by 364 community and environmental groups from across the country, urged the government’s top environmental watchdog agency to adopt strict new air pollution standards for industrial plants that produce plastic.

More than two dozen protesters, some dressed in hazardous materials suits and gas masks, waved signs railing against plastic pollution before presenting their demands to the EPA’s Region 9 office at 75 Hawthorne St.

“Plastic plants are poisoning our air and fueling the climate crisis,” said Lauren Packard, a lawyer for the Center for Biological Diversity, who wrote the petition on behalf of the various groups. “The EPA has to act now.”

Margot Perez-Sullivan, the EPA spokeswoman for Region 9, said the agency accepted the petition and met with the groups to discuss their concerns.

“We value input from all stakeholders,” Perez-Sullivan said. “The petition calls for national rule-making actions and has therefore been shared with the agency’s national leadership. EPA will review the petition and continue to work with stakeholders to address environmental and public health concerns.”

The EPA’s regional office in San Francisco has jurisdiction over California, Nevada, Arizona, Hawaii, the Pacific Islands and 148 tribal nations.

Petrochemical production is one of the nation’s fastest-growing fossil fuel industries and emits almost as much greenhouse gas into the atmosphere as vehicles do. The petitioners say it is natural-gas fracking that is driving the boom in plastic production.

The pollution, which primarily impacts low-income communities, includes methane and gas leaks during extraction as well as the calamitous amounts of plastic floating around in the oceans and landfills, the petitioners said.

“Using fracked gas to make yet more plastic manages to combine many of our environmental sins into one diabolical bundle,” said Bill McKibben, founder of the environmental organization 350.org. “And the first victims — of both the climate change and the air pollution — are the most vulnerable people on our planet and in our nation.”

Petrochemical plants are primarily located along the Gulf Coast and in Appalachia, but there is one plant called Ineos, in Carson (Los Angeles County). Fracking also occurs in California, but it is for oil, not gas.

Packard said the petrochemical plants emit hundreds of tons of toxic, carcinogenic pollutants, including butadiene, acetaldehyde, benzene and formaldehyde. She said 300 new petrochemical projects have been proposed in the country and are now waiting approval.

“The EPA is still handing out these permits willy-nilly,” Packard said. “If the Trump administration is not going to act, hopefully whoever is voted in in 2020 will.”

Among the requests outlined by the environmental groups are that the EPA update decades-old air-pollution monitoring and control standards under the Clean Air Act and require all new petrochemical plants to be powered by renewable energy. Another petition was presented in July demanding an end to plastic pollution under the Clean Water Act.

It would appear, given recent Trump administration actions, that a crackdown on petrochemicals and plastic is not a likely outcome of the petition. California has been battling the federal government over everything from tailpipe-emissions rules to oil drilling off the coast.

Gov. Gavin Newsom announced last month that state agencies will stop purchasing vehicles from automakers who comply with President Trump’s proposed relaxation of greenhouse gas emissions standards. State Attorney General Xavier Becerra joined prosecutors from 22 other states in filing a lawsuit last month blocking EPA efforts to strip parts of the federal waiver allowing California to create its own tailpipe rules.

Peter Fimrite is a San Francisco Chronicle staff writer. Email: pfimrite@sfchronicle.com. Twitter: @pfimrite