Torrance Refinery has not proven that it can contain the spread of a deadly chemical if it were released and formed a dense vapor cloud, according to findings the South Coast Air Quality Management District is scheduled to share in detail on Wednesday.

The chemical – Modified Hydrofluoric Acid, or MHF – is the subject of a ban proposed by the AQMD. A public meeting to inform the agency’s rulemaking process is scheduled at the agency’s Diamond Bar headquarters.

Two local refineries, Torrance Refinery and Valero Wilmington. are the only ones in California that use MHF. Spokespeople for both refineries said they continue to oppose a ban of the chemical.

In May, Torrance Refinery officials walked AQMD and stakeholders through their case for continuing to use the toxic chemical. The company argues that rigorous testing shows MHF does not form a dense, ground-hugging cloud and thus is safe.

But scientists at the South Coast Air Quality Management District were not persuaded by the company.

Materials released by AQMD for Wednesday’s report said Torrance Refinery has not proven that a dense vapor cloud would not form and move off-site in a spill. The AQMD said a quarter million people living or working within 3 miles of the refinery could be affected in a worst case spill of more than 500 gallons of MHF.

In its findings, the AQMD questions the assumptions and calculations used to model what could happen if the toxic chemical were released.

The AQMD scientists also took issue with the company’s reliance on various barriers, like shields and water sprays to keep the chemical from forming a cloud if it did leak.The barriers might not work if a leak occurred during an incident that also damaged the equipment, or caused a power outage or loss of water pressure.

The AQMD report says it will ask stakeholders and the refinery for input on the timetable to phase out the use of MHF at Torrance Refinery.

Phasing out MHF at Torrance Refinery would be no small task. The refinery produces one-fifth of the gasoline used in Southern California and one-quarter of the jet fuel planes consume at LAX.

The finding validates research done by the activist group Torrance Refinery Action Alliance, president Sally Hayati said.

“The AQMD position is that if MHF is fine, you should have an ironclad case and be willing to make it public,” Hayati said. The report said Torrance Refinery had not done so.

TRAA’s science advisory panel includes several chemical engineers and scientists who dug into industry and patent and other data to better understand the risk of living near a refinery using MHF.

The chemical has become controversial in recent years after an explosion at the Torrance refinery nearly pierced a tank containing thousands of pounds of the MHF. The United States Chemical Safety Board called the incident a near miss with the potential to harm residents who live near the refinery. The refinery was closed for more than a year after the February 2015 explosion.

The Torrance Refinery Action Alliance, which wants the chemical banned, is now asking Torrance’s mayor and City Council to endorse the ban being drafted by AQMD

Torrance Refinery spokeswoman Betsy Brien says the refinery wants AQMD to challenge TRAA’s research.

“We ask them to look at the TRAA’s data as stringently as they are looking at ours,” she said.

It could cost a half-billion dollars or more to change its refining process to one that uses sulfuric acid rather than MHF, she said Tuesday. A ban could be in draft form by the end of the year.

Valero spokeswoman Lillian Riojas said the AQMD had cleared her company’s refinery in Wilmington to use MHF in 2004 and again in 2007.

“It’s curious the SCAQMD deemed Wilmington’s (MHF) process safe then, yet today, is seeking drastic changes when there have been no HF (Hydrofluoric Acid) related safety issues,” she said in an email statement.

*Original article online at https://www.scpr.org/news/2017/08/22/74922/could-torrance-refinery-keep-toxic-leak-from-homes/