President Trump’s environmental chief Scott Pruitt visited the Environmental Protection Agency’s San Francisco headquarters on Friday morning, attracting dozens of protesters who chanted for clean air and blasted the administrator’s policies in speeches outside the building.

Bradley Angel, executive director of Green Action, organized the rally of about 75 people after receiving a phone tip several days ago from a “high-level EPA whistleblower.”

“We don’t know the purpose of his visit here,” Angel said. “Pruitt has taken secrecy and lack of transparency to another level.”

Kelsi Daniell, an EPA spokeswoman, said that Pruitt was in San Francisco to meet with Region 9 staff and discuss air and water quality issues, toxic Superfund sites in the region and the agency’s response to extreme events, such as wildfires and volcanic eruptions.

The EPA’s Region 9 covers California, Nevada, Arizona, Hawaii and the U.S. Pacific Islands.

Pruitt also met with Mary Nichols, chairwoman of the California Air Resources Board, to talk about “cooperative federalism, car and truck greenhouse gas standards,” and the National Ambient Air Quality Standards, Daniell said.

Clean air standards have become a contentious issue for Pruitt, who on Wednesday was sued by California and 10 other states, and the District of Columbia.

The lawsuit alleges Pruitt violated the Clean Air Act by issuing guidance that permitted companies to incorporate hydrofluorocarbons, a refrigerant that is a potent greenhouse gas, in their products.

“I’ve said it before and I’ll say it again: EPA Administrator Scott Pruitt is not above the law. That is why we are taking him to court,” California Attorney General Xavier Becerra said in a statement. “He should be working to protect our environment, but instead he wants to unlawfully allow more companies to use these very potent climate pollutants.”

House Democrats have also requested that the Justice Department investigate Pruitt for criminal conduct for possible violations of federal anti-corruption laws.

Michael Stoker, an administrator Pruitt appointed last month to oversee Region 9, met with protesters outside EPA’s Hawthorne Street headquarters Friday, Angel said, but Stoker would only talk to them on the condition that they speak in private. Angel said he declined and preferred to have Stoker talk to the crowd.

Mary Sweeters, a climate campaigner with Green Peace, criticized Pruitt’s leadership of the EPA, which has been dogged by a series of reports of questionable spending and conflicts of interest amid numerous regulatory rollbacks.

“There have been so many scandals in the news around Scott Pruitt,” Sweeters said. “The real scandal we want to highlight is that before he even came into office, he’s been fighting regulations that aim to protect clean air and clean water across the country.

“We’re out here to hold people like Pruitt accountable, because these decisions have repercussions for generations to come.”

On Thursday, Pruitt and Stoker were in Santa Barbara County to tour the Casmalia Superfund site, where they announced plans to finalize toxic clean-up operations over five years at a cost of $60 million.

Pruitt said in a statement that he added the contaminated soil and groundwater of Casmalia to his “emphasis list of sites requiring immediate, intense action,” and the EPA will carry out the operation “in a comprehensive and lasting manner.”

On Friday, Angel and other protesters stressed a similar sense of urgency in opposing Pruitt’s leadership of the EPA.

“I don’t think the stakes have ever been higher in my lifetime,” Angel said.

Erin Stone and Josh Koehn are San Francisco Chronicle staff writers. Email: erin.stone@sfchronicle.com, josh.koehn@sfchronicle.com Twitter: @Erstone7 @Josh_Koehn