As the South Bay community marks the 10th anniversary of an explosion at Torrance Refinery, advocates and elected officials are renewing their efforts to ban modified hydrofluoric acid at the facility, including via federal legislation.

The 2015 explosion at the refinery, which registered as a small earthquake, left four workers injured and covered the surrounding communities in catalytic dust. But it also ignited a movement against the use of modified hydrofluoric acid, at both the Torrance Refinery and Valero’s Wilmington Refinery, the only two in California that still use the chemical in their refining operations.

Modified hydrofluoric acid is used to refine high-octane gasoline. While advocates — ranging from a local activist group to the California attorney general and numerous other elected officials — say the safety risks posed by the acid to the surrounding communities is too high, refinery representatives have repeatedly argued that it’s the safest commercially viable option currently on the market.

Although the explosion in February 2015 didn’t involve modified hydrofluoric acid or result in a leak of the acid, it has since been dubbed a “near miss,” because the explosion launched a 40-ton piece of debris that came just 5 feet away from puncturing storage tanks carrying tens of thousands of gallons of the acid, among other chemical components.

“Had the tank ruptured, it would have caused a release of MHF, which is highly toxic,” the U.S. Chemical Safety and Hazard Investigation Board said in a 2017 investigation report about the refinery explosion, which also found the incident could have been avoided entirely, if not for lax safety protocols put in place by then-owner Exxon Mobil Corp.

Tests have shown that modified hydrofluoric acid rapidly expands upon release and can travel at lethal concentrations up to 2 miles, according to a presentation from South Coast Air Quality Management District staff.

Both the Torrance and Wilmington refineries are situated in densely populated areas of the South Bay: About 245,000 people live within 3 miles of Torrance Refinery and another 153,000 live within that same distance of the Valero refinery, AQMD said. Thousands of people could have been harmed if the modified hydrofluoric acid had dispersed beyond the Torrance refinery in 2015, the safety board report said.

Exxon Mobil, not long after the explosion and subsequent pushback from the community to stop using modified hydrofluoric acid in its refining processes, sold the facility to PBF Energy. The company has repeatedly argued that the acid does not pose a significant risk to public safety, especially because they’ve put in place several new safety protocols over the past decade to mitigate an off-site release of the chemical in the event of an emergency.

“As we have shown, our robust safety systems are multi-layered and redundant, fully capable of containing and preventing an offsite impact of MHF, protecting refinery personnel and the community,” PBF Energy representative Abena Williams said in a statement Tuesday, “while allowing Torrance Refinery to reliably produce alkylate, a critically important blending component required for producing California-compliant reformulated gasoline that helps fuel California’s economy.”

Still, elected officials, including Rep. Maxine Waters, D-Los Angeles, alongside community members and activists from the Torrance Refinery Action Alliance, aren’t convinced that those safety measures can fully protect the community in the event of a crisis.

Waters, alongside members of the alliance and others, gathered at the Mary K. Giordano Regional Transit Center — mere blocks from the Torrance Refinery — on Feb. 15 to commemorate the 10th anniversary of the explosion and to announce new efforts to ban modified hydrofluoric acid, including federal legislation that’s currently in the works.

“Torrance Refinery should be commended for their safety investments,” Waters said Feb. 15. “But the risks of a catastrophic release of HF cannot be eliminated as long as the refinery continues to use it. It’s time for the Torrance Refinery to just do the right thing and convert to a safer alternative.”

history of battle

Though concerns about modified hydrofluoric acid and hydrofluoric acid have come to a head in the past decade, the chemical has been the topic of scrutiny since the 1980s.

In 1987, after a decade of safety incidents caused by the refinery, Torrance sued Mobil Oil Corp., which would eventually become Exxon Mobil. The city’s complaint against the Torrance Refinery reported hundreds of major safety incidents up until that point and specifically called out the facility’s use of hydrofluoric acid, arguing that even under the strictest safety standards, the refinery would still be vulnerable to a catastrophic release of the chemical.

After the city filed its complaint, a major accident at the Torrance Refinery — a 100-pound release of hydrofluoric acid in an explosion and fire, according to an U.S. Environmental Protection Act report to Congress — Mobil chose to settle the lawsuit out of court, resulting in the Torrance consent decree.

The consent decree gave Mobil two options: Reformulate hydrofluoric acid to prevent it from forming a ground-hugging vapor cloud that can travel for miles in the event of a catastrophic release or stop using it by 1997.

And thus, modified hydrofluoric acid, a product of collaboration between Mobil and Philips that was successfully commercialized in 1997, was created. The key difference between modified hydrofluoric acid and hydrofluoric acid is that the former contains an additive meant to prevent the formation of that ground-hugging cloud should there be a leak during refining operations.

It wasn’t until the 2015 explosion that modified hydrofluoric acid once again became a topic of great concern for residents, environmentalists and regulatory agencies alike.

The event spurred AQMD to begin deliberations on Proposed Rule 1410 in the years after. That proposed rule would have required both the Torrance and Wilmington refineries to phase out modified hydrofluoric acid or switch to an alternative, such as sulfuric acid, which other refineries in the U.S. use and advocates argue is safer.

The air quality watchdog held more than 20 community meetings from 2017 to 2019 about the use of modified hydrofluoric acid at the Torrance and Wilmington refineries throughout the legislative process surrounding Proposed Rule 1410.

The rule had support from countless officials from across the state, including Reps. Nanette Barragán, D-San Pedro; Ted Lieu, D-Torrance; and Waters, alongside the Los Angeles County Department of Public Health and former California Attorney General Xavier Becerra.

Activists from the Torrance Refinery Action Alliance have repeatedly called the efficacy of modified hydrofluoric acid into question, a concern that was also iterated by AQMD’s own staffers, whose reports during the Proposed Rule 1410 process warned that the “ability of MHF to prevent formation of a vapor/aerosol cloud is highly uncertain” and that a “release of MHF will result in exposure to HF with the same health effects.”

But just a week before the AQMD Governing Board was set to vote on the proposal, both PBF Energy and Valero released proposals outlining their plans to invest in modifications aimed at making the use of modified hydrofluoric acid in the refining process safer.

And the board accepted.

Proposed Rule 1410, after four years, died on the board’s floor in 2019 — and, instead, was replaced with the safety proposals from both refineries.

That process, Williams of PBF Energy said, “led to an agreement that allows the Torrance refinery to continue safely using MHF and the installation of additional voluntary safety measures.”

Since 2019, according to Torrance Refinery’s website, PBF Energy has installed a new protective steel structure around its alkylation unit, as well as a water mitigation dome and curtain, an expanded water deluge system, a hydrofluoric acid/modified hydrofluoric acid laser detection system, water mitigation monitors and more.

“The bottom line is Torrance Refinery now has the most advanced safety systems of any HF Alkylation Unit in California, the U.S. and the world,” the refinery’s website says. “In addition, please keep in mind there are at least 50 other HF users in Southern California and more throughout the state, especially in agriculture, refrigeration and high-tech applications.”

It’s unclear what steps Valero has taken to increase modified hydrofluoric acid-related safety measures at its Wilmington facility since 2019. The company did not respond to requests for comment on this story and does not have any public information about the chemical on its website.

Still, in 2023, the Los Angeles County Board of Supervisors took up the issue of modified hydrofluoric acid. Supervisor Janice Hahn, who represents Torrance, introduced a motion that year asking Gov. Gavin Newsom and state Attorney General Rob Bonta’s office to require refineries using the acid to convert to a similar alternative.

Hahn served on AQMD’s board at the time of the modified-hydrofluoric-acid ban vote, and was one of just two “no” votes against the refineries’ counter offers to the ban.

Hahn’s motion, meanwhile, received unanimous approval and also directed L.A. County to support any new legislation that could help phase out modified hydrofluoric acid at the Torrance and Valero refineries.

Little has changed since then.

Yet, while both refineries still use modified hydrofluoric acid, some new developments could cause challenges for the refining industry in the near future.

Federal legislation

For the first time, a federal effort to force refineries to phase out modified hydrofluoric acid and hydrofluoric acid is in the works, according to Waters.

She introduced House Resolution 10441 — dubbed the “Preventing Mass Casualties from Release of Hydrofluoric Acid at Refineries Act” — just before Congress adjourned in December.

The bill, Waters said Feb. 15, would amend the existing Toxic Substances Control Act to prohibit the use of hydrofluoric acid to refine petroleum at new refineries and would require existing refineries currently using the chemical to convert to an alternative within five years. There are about 42 refineries using hydrofluoric acid across the country today.

That bill had 10 co-sponsors, including Lieu, Barragán and Rep. Robert Garcia, D-Long Beach, alongside a smattering of environmental groups, such as California Environmental Voters, Public Employees for Environmental Responsibility, the Sierra Club and, of course, the Torrance Refinery Action Alliance.

After introducing her legislation, Waters said, she met with various industry groups, including the United Steelworkers. That trade union represents more than 850,000 members and retirees in various industries across the U.S., Canada and the Caribbean, according to its website, including some workers at the Torrance Refinery.

“USW agreed with me that HF is dangerous for the workers and the surrounding communities and that HF should be eliminated from refineries,” Waters said, “but they said they have concerns about my bill.”

The union’s qualms, Waters said, include safety concerns about the potential alternative: sulfuric acid. But they’re also worried that if the refineries are forced to convert to an alternative, which could be a prohibitively costly move, that unionized workers would bear the brunt through job losses.

A 2022 industry study, conducted by Becht for theAmerican Fuel & Petrochemical Manufacturers, estimated that it could cost anywhere from $200 million to $850 million to replace an existing hydrofluoric acid alkylation unit with a sulfuric acid unit, depending on the size.

“USW is also concerned that if refineries are forced to convert to a safer technology too quickly, some of the refineries might close — leaving their workers without jobs,” Waters said. “(They) suggested that I amend my bill to direct the (U.S.) Department of Energy to do research on safer technologies and then provide incentives to the refineries to convert to the best possible alternative.”

Waters said that she would consider all of the feedback before reintroducing the bill to Congress, which she plans to do once the terms of it are refined and she secures additional sponsors for it.

“Let me just share with you the way that Congress works in the introduction of bills — that’s a real beginning, and a lot of things begin to happen,” Waters said. “We, of course, have some supporters who have joined us, and we’re looking for more. As we continue to work on the bill, we think we will be able to get even more people endorsing the bill. The more members that we have endorsed in the bill, the greater the fight that we can pick up.”

Some potential changes that could be included in the bill text, Waters said, include identifying the Department of Energy as the body that would be responsible for researching commercially viable hydrofluoric acid and modified hydrofluoric acid alternatives, and determining a realistic timeline for refineries to convert away from the acids.

Sulfuric acid alkylation could be an option. But another technology, a Honeywell invention that doesn’t use hydrofluoric acid or sulfuric acid, was used to convert Chevron Corp.’s Salt Lake City refinery from hydrofluoric acid to the new alternative in 2021.

Torrance Refinery, though, still argues that the alternatives haven’t yet been proven commercially viable on the scale the facility needs for its operations — though Williams said PBF Energy continues exploring alternatives as required by federal and state law.

“Although one small-scale, alternative alkylation option is being beta-tested on a relatively small scale, the new technology has yet to be proven safe and reliable from a mechanical integrity perspective, and commercially viable at the scale of the Torrance Refinery Alkylation Unit,” Williams said. “Until we know more about possible alternatives, we consider MHF to still be the safest, proven and superior alternative alkylation technology option for Torrance Refinery at this time.”

As for Waters’ bill, there is no exact timeline for when it’ll be reintroduced.

“We don’t know exactly when (the bill will be introduced), (but) as soon as possible,” Waters said. “I’m worried, of course, about the Department of Energy and what’s happening over there.”

The Trump administration, as of Feb. 14, had laid off around 1,200 to 2,000 workers from the Department of Energy.

Those layoffs came after representatives from Elon Musk’s Department of Government Efficiency arrived at the DOE last week, according to Reuters. Musk, the billionaire owner of SpaceX and Tesla, has been named director of that new department by President Donald Trump to aid the administration’s efforts to reduce government spending, at least partially through layoffs. (SpaceX has long been based in Hawthorne, though Musk said last year that its headquarters would move to Texas.)

“(Musk) has just stripped the Department of Energy,” Waters said. “So we know that when we get suggestions, we’re not always fooled or tricked into believing that the suggestions are as sincere as they may sound, but rather it may be an attempt to put up a roadblock.”

But even with concerns about the administration’s sweeping changes to how the federal government operates, and increasing vitriol between Republicans and Democrats in policymaking, Waters said she has hope her bill will be able to cut through the noise.

“I have members on the opposite side of the aisle that I will be talking to. They’re more conservative on many of the issues — but there’s no reason why safety should not be a bipartisan concern,” Waters said. “We may be able to pass bills and get things done with just three members from the opposite side of the aisle. And so we will be working on that.”

Williams, meanwhile, said that PBF Energy is aware of Waters’ proposed legislation and that the company is monitoring it.

“We have met with Representative Waters’ staff several times,” Williams said, “and we have extended invitations to the Representative, Supervisor Hahn, and Chemical Safety Board to tour our facility, which we still offer.”

Waters, meanwhile, said she was committed to the bill, and is doing everything she can to get it passed.

“We’re not going to be misled, and I’m not going to be dragged out for two years in this next session trying to get to an agreement,” Waters said. “I’m going to be as nice as I can be — and sometimes I’m not so nice. I am not about to let you down.”

Besides Waters’ legislation, the Natural Resources Defense Council also recently filed a petition with the U.S. Environmental Protection Agency, asking it to ban the use of hydrofluoric acid at all refineries under an existing federal act.

The EPA has 90 days to review the petition, and either ignore or deny it, Communities for a Better Environment representative Jay Parepally said at the Feb. 15 event. Communities for a Better Environment partnered with the defense council and Philadelphia’s Clean Air Council to submit the petition. (Philadelphia was the site of a 5,000-pound hydrofluoric acid leak in 2019.)

If the petition isn’t successful, Parepally said, the organization can take the matter to court and ask a judge to rule that the use of hydrofluoric acid in refineries presents an unreasonable risk.

“This could be a really good complimentary effort to what Congresswoman Waters is working on in the legislative branch,” Parepally said, “and hopefully, with a combination of Environmental Protection Agency and judicial activity, we can see some progress as well.”

Torrance Refinery, for its part, remains steadfast in arguing the safety of modified hydrofluoric acid.

“The cleaner-burning gasoline sold in California requires alkylate to comply with the most stringent tailpipe emissions requirements in the world,” Williams said. “The Torrance Refinery has been safely and reliably manufacturing alkylate for transportation fuels using hydrogen fluoride (HF), including MHF, in its Alkylation Unit for more than 60 years, without any off-site impact.”

For the Torrance Refinery Action Alliance, which has been at the forefront of the fight to ban modified hydrofluoric acid locally for nearly a decade, the renewed efforts — at a higher level of governance than ever before — offer some hope that their mission may be accomplished.

“The people in Torrance, in the South Bay, and really all over have joined this movement,” the alliance’s president, Steve Goldsmith, said Feb. 15. “It’s very inspiring.”