“Modified” hydrofluoric acid (MHF) is a dangerous industrial chemical used in massive quantities in only two California refineries, Torrance and Valero, Wilmington. If released, it forms a ground-hugging cloud that can drift for miles, causing death and injury. The refineries’ other mitigation measures, like water sprays and barriers, are also ineffective. Mass casualties can result from an MHF release — wind direction determines who dies.

Results of 2015 explosion that nearly released 50,000 lbs of MHF, which could have killed or injured tens of thousands, according to the U.S. Chemical Safety Board


For decades, the South Bay has battled the refineries’ all-too-successful campaign to keep using MHF rather than converting to a much safer process, such as is used at Chevron in El Segundo and the other California refineries. Following the massive Torrance refinery explosion in February 2015, which nearly released 50,000 lb of MHF, investigations by TRAA and the U.S. Chemical Safety Board uncovered the true threat MHF poses. Now, the South Coast Air Quality Management District (SCAQMD) is considering Rule 1410 to require MHF/HF replacement with a safer alternative at both refineries. But industry is fighting back with well-financed campaigns.


Let the SCAQMD and our elected officials know that you support public safety!

Step 1:

Email the SCAQMD Board members demanding a strong Rule 1410 to Phase-Out MHF in 4 years. We’ve made it easy–just click here to find out how.

Step 2:

Sign our petition to demand that refineries replace HF/MHF with a safer alkylation alternative process.  Click here to sign our petition.


Click image to watch a terrifying video of the Philadelphia Energy Solutions refinery explosion on Friday, June 21, 2019. Note object being hurled from the explosion to the right. With the PES refinery closing, now Torrance CA has the infamous distinction of having the densest population around an HF refinery.  The video is from 6abc/WPVI−TV Action News in Philadelphia.

  • Supervisor Hahn Responds to SCAQMD Vote to Drop Phase-out of MHF September 9, 2019 FOR IMMEDIATE RELEASE September 6, 2019 Contact: Liz Odendahl o: (213) 974-4444 c: (213) 379-6301 Supervisor Hahn Disappointed in SCAQMD Vote to Allow Refineries Continued Use of Deadly Chemical in Torrance and Wilmington  Diamond Bar, CA— Today, Supervisor Janice Hahn is speaking out against the SCAQMD Governing Board’s decision to drop their pursuit of a rule that would phase out and ...
  • Refineries quietly try to end Hydrogen Fluoride (HF) regulation on Friday, 9/6/19 September 5, 2019 The two refineries using “modified” Hydrogen Fluoride (HF) in California are quietly trying to escape from further regulation of HF by offering to add more water sprays, sensors, and barriers.   But they would only agree to do this do this if the AQMD agrees not to do any further regulation of HF in their refineries. These ...
  • Long Beach Mayor Garcia Urges SCAQMD to Begin Immediate Phase Out HF July 12, 2019 Long Beach Mayor Robert Garcia has sent a letter to the SCAQMD urging that the SCAQMD “take steps that ensures that proposed Rule 1410 addresses our concerns and begins the phase-out process of MHF immediately.”
  • SCAQMD Rule 1410 Refinery Committee Meeting June 11, 2019 The SCAQMD Rule 1410 Refinery Committee Meeting is 6/22 in Diamond Bar at 10 am. Join our caravan to the event or ride the bus.
  • Call to Action: Urge Gov. Newsom to Protect Our Community May 28, 2019 Gov. Newsom will soon appoint a new member of the SCAQMD Governing Board. Urge him to select someone who will prioritize our community.
  • Call to Action: Request AQMD Committee Meeting to be Held in South Bay May 26, 2019 The AQMD is tentatively planning the next Refinery Committee Meeting in Diamond Bay. Urge the AQMD to assist local residents to be heard by holding the meeting in the South Bay.
  • LA County Public Health Official Urges Phase Out of MHF April 5, 2019 The Los Angeles County Department of Health has sent a letter to the South Coast Air Quality Management District urging the phase out of MHF as soon as possible. Angelo Bellomo, the county deputy director for health protection stated in a letter that a large scale release of MHF “would have potentially catastrophic impacts ...
  • Court Protects MHF Documents for Big Oil November 9, 2017 NEWS FLASH! A court order has been issued, responding to a May 2017 DoJ Petition to enforce U.S. Chemical Safety Board (CSB) subpoenas for information on the 2015 Torrance explosion. The court DENIED virtually every request related to the modified hydrofluoric acid (MHF) unit, needed to determine the causes and potential consequences of the NEAR ...
  • TRAA Meets with CA Assemblywoman Cristina Garcia October 13, 2017 This past week, TRAA met with Assemblywoman Cristina Garcia, (who represents the 58th District of California: Bell Gardens, Pico Rivera, Downey, Cerritos, etc) as part of TRAA’s campaign to win support for a ban on MHF by means of AQMD Rule 1410 and AB 1645. TRAA presented information about the dangers of MHF and the achievements ...
  • Another Victory! October 11, 2017 But we still have a lot of work ahead of us…. Governor Jerry Brown signed 3 of Assemblymember Al Muratsuchi’s Refinery Safety bills. It is a bittersweet moment. These bills sailed through. But CA politicians sat on Muratsuchi’s AB 1645 to BAN modified hydrofluoric acid (MHF) alkylation. Unfortunately, we may not get the region-wide sectored siren ...