Investigation of HF acid in California regarding AB 1759

THE INVESTIGATION OF INDUSTRIAL USE OF HYDROFLUORIC ACID IN CALIFORNIA
REGARDING LEGISLATIVE BILL AB 1759
JAMES BOOTH
EVAN CHOY
HAIMING HU
MANSU LIU
ERIKA POYNTER
Department of Mechanical and Aerospace Engineering, UC San Diego
June 7, 2016

June 2016 Hydrofluoric Acid AB-1759
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EXECUTIVE SUMMARY
Background
In 2015, ExxonMobil’s Torrance refinery had two separate incidents involving hydrofluoric acid, sparking an ongoing
public debate regarding the petroleum industry’s use of the dangerous chemical while being close in proximity to residential
areas. In response to the events, California Bill AB-1759 was drafted and proposed to take effect immediately. Under section
25240.2(a), (b), the California Legislature declared that any business that, at any time, handles, maintains, or stores more
than 250 gallons of hydrogen fluoride, including hydrofluoric acid, shall, if possible convert to a known, substitute by
January 1, 2017. If it is not possible to convert to a known, significantly less hazardous substitute, and the business is located
within two miles of a residential dwelling, the business shall cease handling, maintaining or storing hydrogen fluoride and
hydrofluoric acid by January 1, 2017.
This report, developed in response to the California Bill AB-1759 and with the help of the Industrial Environmental
Association (IEA), is intended to identify the use hydrofluoric acid (also called HF) in different industries, the properties of
different concentrations of HF used, and potential hazards and risk to the public. The report is to determine whether AB-
1759 in its current form is justifiable or if changes ought to be made.
Summary of Findings and Recommendations
HF is a very toxic and corrosive inorganic acid. HF is used as the source of the fluorine molecule for the production of
fluorinated compounds. It is involved in the alkylation process to produce high octane fuel and is also used as an etching
agent in metalworking and etching industries. Furthermore, it is used to produce organofluorine compounds. HF is also
commonly used in common household products such as water spot removers, rust stain removers, and in ceramic and fabric
rust inhibitors. It is a fairly common compound that is used in varying concentrations for numerous processes.
An accidental release of industrial HF could have fatal consequences. HF is toxic to humans and can be extremely lethal as
documented by many workplace accidents. At 40% concentration and standard air pressure conditions, HF begins to fume.
At 70% concentration and standards conditions, it reaches its maximum saturation level and becomes highly volatile, fuming
heavily. Oil refineries use modified HF, which, under pressure, can reach even higher concentrations. At such high
concentrations, under certain conditions, and in large quantities, HF has the potential to form a dense vapor cloud that can
travel significant distances downwind posing a potential fatal threat to the public. It requires immediate and specialized
medical attention to treat HF exposure properly. As such, public safety is a significant concern for oil refineries which tend
to use high concentrations of HF and own facilities that are close to densely populated areas.
Bill AB-1759’s intent is to protect densely populated areas from the potential worse-case scenario of a HF vapor cloud
forming from an oil refinery. While this is undoubtedly a concern, the current legislature makes no mention of acceptable
hydrofluoric acid concentration/vapor pressure levels, a crucial omission. There are numerous companies that use low
enough concentrations (often 49% or lower) that formation of a dense HF vapor cloud does not seem possible.
Additionally, after reviewing multiple environmental agency’s reports such as the EPA, the U.S Chemical Safety Board,
CalARP, and OSHA, the conclusion was reached that the likelihood of an accidental release of HF can be kept low so long
as the facility managers and operators work responsibly by applying existing industry standards and practices, and adhering
to existing federal/state regulations.
Businesses that follow strict safety protocol and have protective measures that mitigate the spread/exposure of HF if
released. All facilities should be able to identify, mitigate, and quickly respond to accidental releases in order to minimize
the hazards. The U.S. Chemical Safety Board did not propose a ban on hydrofluoric acid in oil refineries, but believe that
the accidents that have happened in the past could have been avoided with a more analytical and structured approach that
could have helped to prevent or mitigate the effects of these accidents. The U.S. Chemical Safety Board recommended that
substantial changes need to be implemented to the way refineries are regulated in California. Chairperson Sutherland said,

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“The CSB is continuing to advocate for its process safety management recommendations and monitor
developments in California…the actions being taken in the state are some of the most substantive safety
improvements happening the United States right now.”[25]
Our first recommendation, which is less drastic than this bill, is to more stringently enforce the current federal and state
laws regarding HF. As discussed earlier, there is already an extensive network of standards and regulations for facilities
using HF. The current regulations, when properly followed, tremendously reduce the likelihood of an accident, as seen with
companies like UTC Aerospace and Air Products & Chemicals, which have not even had a minor HF accident affecting the
public. On the other hand, the Torrance refinery incident arose because current standards and regulations were not being
adhered to by management. We propose that to ensure these regulations are followed, the penalty fines associated with
violations be substantially increased. These fines can then be used to offset the costs of the additional and stricter inspections
incurred in this process
We strongly recommend that the bill recognize the difference in threat level that HF poses at difference concentrations, as
is done with other chemicals such as hydrochloric acid. The hazard posed by a 30% concentration HF solution cannot
reasonably be compared to a 70% concentration HF solution. As such, we propose that the bill follow federal guideline
practices and focus on facilities that handle HF concentrations over 50% such as oil refineries. Furthermore, due to its effect
on fuming, the bill should seriously consider the establishment of a vapor pressure threshold. Many companies in California,
such as Air Products and Chemicals and UTC Aerospace, responsibly use HF at concentrations less than 50% at standard
air pressures, and their working conditions present minimal public safety threat. To force these companies to halt the use of
HF would be catastrophic to California’s economy, yet would not provide the public safety benefit that the bill seeks.
If our other proposals are not to be followed, our final proposal (and as a last resort) is that the bill should extend the time
period before it goes into effect as to allow for additional time if it is going to force oil refineries to find a safer alternative
to use in the alkylation process.
The United Steel Workers Study has concluded that there are a few alternatives to HF. The first, which replaces HF with
sulfuric acid alkylation has already been implemented in some refineries, though it has its drawbacks. As discussed in
section 4.5, sulfuric acid is much safer than HF but it still poses serious hazards for workers, the public and the environment,
and is not for certain an effective alternative. Secondly is solid-acid catalyst alkylation which has been studied and
implemented by a few companies. Another is ionic-liquid alkylation, a process that has been successfully developed and
implemented in Chinese refineries and is in the pilot and production phase. The two processes are much safer for workers
and the public because of it does not use HF or sulfuric acid. However, more research and studies must be conducted in
order to determine if either are a reliable alternative and are able to meet California’s unique gasoline blend regulation. With
all factors considered, there is absolutely no way an alternative will be available by 2017. Furthermore, any alternative will
come at enormous costs, costs which could be enough to force the shutdown of refineries.

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Table of Contents
1. Introduction …………………………………………………………………………………………………………………………………………………………………6
1.1 Project Definition..........................................................................................................................................................6
1.2 California Bill AB-1759...................................................................................................................................................6
1.3 Objective.......................................................................................................................................................................6
2. Background of Hydrofluoric Acid…………………………………………………………………………………………………………………………………..6
2.1 Chemical Properties......................................................................................................................................................6
2.2 Risks to Human Health..................................................................................................................................................7
2.3 Hydrofluoric Acid use in Industries...............................................................................................................................7
2.3.1 Oil Refineries..........................................................................................................................................................7
2.3.2 Etching and Microfabrication.................................................................................................................................8
2.3.3 Organo-fluorine Compound Production................................................................................................................8
3. Methods and Procedure……………………………………………………………………………………………………………………………………………….8
4. 2015 ExxonMobil Incidents propagated AB-1759………………………………………………………………………………………………………….8
4.1 Torrance Refinery Explosion .........................................................................................................................................9
4.1.1 Torrance Refinery Explosion Investigation ............................................................................................................9
4.1.2 Management of Change Review..........................................................................................................................10
4.2 Response to the February Explosion...........................................................................................................................10
4.3 Hydrofluoric Acid Leak at the Torrance Refinery........................................................................................................10
4.4 Response to the Hydrofluoric Acid Leak.....................................................................................................................11
4.5 ExxonMobil Torrance Refinery Aftermath..................................................................................................................12
5. Industry Analysis…………………………………………………………………………………………………………………………………………………………13
5.1 Standard Handling and Emergency Procedures..........................................................................................................13
5.2 Air and Chemical Products..........................................................................................................................................13
5.2.1 Concentration/Amount stored and used.............................................................................................................14
5.2.2 Safety Procedure..................................................................................................................................................14
5.2.3 Bill’s Effect on Industry ........................................................................................................................................14
5.3 UTC Aerospace Systems..............................................................................................................................................14
5.3.1 Concentration/Amount stored and used.............................................................................................................14
5.3.2 Safety Procedure..................................................................................................................................................15
5.3.3 Bill’s Effect on Industry ........................................................................................................................................15
6. Strong Regulatory System in Place………………………………………………………………………………………………………………………………15
6.1 Environmental Protection Agency .............................................................................................................................15

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6.2 Federal Risk Management Plan...................................................................................................................................15
6.2.1 Risk Management Plans.......................................................................................................................................16
6.2.2 General Duty Clause.............................................................................................................................................16
6.2.3 FRMP Programs....................................................................................................................................................16
6.3 California Accidental Release Prevention (CalARP) ....................................................................................................17
6.3.1 Hazards Assessment & Five-year Accident History..............................................................................................17
6.3.2 Training, Maintenance, & Compliance Audits .....................................................................................................17
6.3.3 Contractors...........................................................................................................................................................17
6.4 Occupational Safety and Health Administration ........................................................................................................17
7. Relationship to Hydrochloric Acid……………………………………………………………………………………………………………………………….18
8. Findings and Recommendations………………………………………………………………………………………………………………………………….18
8. References………………………………………………………………………………………………………………………………………………………………….19
9. Appendix…………………………………………………………………………………………………………………………………………………………………….23

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1. Introduction
1.1 Project Definition
Hydrofluoric acid (HF) is a highly dangerous and volatile chemical which, in high concentrations (approximately 70%), has
the capacity to cause great harm to the public. However, HF is used in numerous industries throughout California and for a
variety of functions. Legislation AB-1759 was proposed to restrict the industrial use of hydrofluoric acid and would greatly
affect the industries in California which use the chemical. The Industrial Environmental Association (IEA), an association
that promotes responsible and economically-wise environmental laws, along with a coalition of companies, were able to put
a hold on the bill before it was able to go into effect. This project calls for a synthesis of facts to create an informative report
to provide to legislators, enabling them to make a collective and informed decision regarding this bill.
1.2 California Bill AB-1759
The entirety of this study is based on the California bill AB 1759 that was introduced on February 2, 2016 by assemblyperson
Rob Bonta. The bill contains two main parts pertaining to the regulation of hydrofluoric acid. The first part calls for all oil
refineries which use hydrofluoric acid to notify the public living within a three-and-a-half-mile radius of the plant’s use of
the chemical. Furthermore, residents living within a two-mile radius shall be warned that they live in the lethal zone (Section
39668.5 (a) & 1.A), which is defined as the area in which individuals will be exposed to life-threatening health effects after
an hour of contact with the toxin, if a release were to occur. (Section 39668.5 (2.C)). The second part calls for all businesses
that handle and store over 250 gallons of hydrofluoric acid on site, and are located within a two-mile radius of residential
dwellings, to either switch to a less hazardous alternative, and if a less hazardous alternative does not exist, cease using HF
altogether by January 1, 2017 (Section 25240.2.a). It is noted that there is no mention of hydrofluoric acid concentration. It
is clear that the priority of the bill is public safety rather than refinery worker safety. The primary fear of a HF vapor cloud
harming nearby residents is apparent in the bill: it states that at any moment 500,000 of the 616,000 Californian residents
living within 3.5 miles of a refinery can be killed due to the presence and potential uncontrolled release of 60,000 lbs. of
modified hydrofluoric acid. According to the bill, an HF vapor cloud can be lethal up to 5 miles downwind.
1.3 Objective
This bill is attempting to stop oil refineries from storing and handling large amounts of modified hydrofluoric acid, but a
blanket ban on hydrofluoric acid will not only affect refineries but also other industries that use relatively safe concentrations
of HF. It could lead to the unintended outcome of entire industries leaving California for states with more lenient regulations,
and thereby causing job losses and a decline in California’s economy.
The objective of this project is to provide an unbiased report to assemblyperson Rob Bonta regarding the bill, which details
the health, economic, and safety impacts of the use of HF. This report will provide a complete picture of the effects of HF
regarding the interests of the state of California and will ensure an informed decision can be made. Lastly, our report will
provide our own recommendations to improve the bill.
2. Background of Hydrofluoric Acid
2.1 Chemical Properties
[16], [17]
Hydrofluoric Acid (HF) is an industrial chemical and is available in both an aqueous and anhydrous form. Aqueous
hydrofluoric acid is a colorless liquid that is produced by dissolving HF in water, thus creating HF solutions at various
concentrations. Under standard conditions, such as those found in university laboratories, aqueous HF will begin to fume at
concentrations around 40%. Relatively dilute HF with concentrations of less than 40% do not produce significant vapor
concentrations unless superheated and placed under large amounts of pressure, conditions that might typically be found in
oil refineries. HF reaches its maximum saturation at 70% (under standard conditions), at which point it is at its most volatile
state and will fume profusely. Anhydrous HF has a much lower boiling temperature than aqueous HF, and thus anhydrous
HF will begin to fume at temperatures close to room temperature, making it much more dangerous than its aqueous
counterpart.

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In both its aqueous and anhydrous forms, HF can cause pressure buildup which can rupture containers when reacted with
glass, concrete and other silicon bearing materials. A reaction with carbonates, sulfides and cyanides will yield toxic gases.
It is corrosive to many materials including leather, natural rubber and other organic materials.
Specific chemical properties for 70% aqueous concentration HF can be found in Figure 1 in the Appendix. Unless otherwise
specified, any mention of hydrofluoric acid in this report assumes aqueous HF.
2.2 Risks to Human Health
[16], [17], [18]
Like other acids, hydrofluoric acid burns skin at varying degrees depending on the concentration. Unsurprisingly,
a higher concentration solution of HF will lead to more aggressive burns and an increase in health complications. The initial
signs of chemical burns are redness at the burn location, blistering, and edema, swelling in the tissues due to accumulation
of extra fluid. Additionally, a high level concentration of HF will blanch the skin at the burn site. A solution concentration
of 0%-49% can delay symptoms for as much as 1-8 hours, which results in a delay in the appearance of need for medical
intervention. During this time however, the HF will begin to cause damage to the skin and underlying tissue. At a
concentration below 19%, symptoms can take as long as 24 hours after exposure to manifest, delaying the apparent need
for medical intervention even longer. Delayed medical treatment allows HF time to seep into the deep tissue and enter the
blood stream causing more severe health complications. A concentration of more than 50% will lead to an immediate and
apparent burn after skin contact, and requires immediate medical intervention.
The fluoride component of HF makes this acid exceptionally more dangerous than other acids. During initial contact, the
fluoride ion enables the HF to penetrate the skin very readily, and it generally takes the body longer to neutralize HF than
other acids. Once HF has entered the body, a throbbing sensation occurs due to the fluoride ion bonding with the calcium
ions in the bloodstream, bones, and other parts of the body. The body compensates by releasing potassium which irritates
nerve ending and thus causes the throbbing sensation. In rare cases, the attraction of fluoride and calcium ions leads to
decalcifying of the bones. If left untreated, skin contact of HF can lead to permanent damage, disability, and even death.
The gas phase of HF is extremely corrosive and can be fatal if inhaled. Chemical burns can occur in at all points of contact
including the eyes, skin and mucous membranes such as the throat, nasal cavity and lungs. Even at low concentrations, the
HF fumes are dangerous if inhaled.
2.3 Hydrofluoric Acid use in Industries
Hydrofluoric acid is used in a variety of industries. For example, it is handled in oil refineries, the metalworking and etching
industry, and in organofluorine chemistry. Very low concentrations of HF are also in household products such as rust stain
remover, water spot removers and in ceramic and fabric rust inhibitors. It is a fairly common compound that is used in
varying concentrations for a number of useful processes.
2.3.1 Oil Refineries
[4]
In oil refineries, hydrofluoric acid is used as a catalyst for the alkylation process with other low-molecular-weight alkenes
to produce high octane rating C7-C8 compounds. High octane rating products are used as a premium gasoline additive to
prevent pre-ignition and knocking in car engines. High octane fuel is necessary for high performance gasoline engines such
as jet fuel for aircrafts.
[5]
Since the protonation of alkenes is the initial critical step in the alkylation reaction, a very strong acidic environment,
usually 83% to 90%, is needed. At low acid concentrations, side reactions such as organic fluorine formation occur, and
acid runaway in which all the acid is consumed in side reactions, can occur. As an alternative to HF, sulfuric acid also
provides good catalytic performance, but this process produces lower octane rating products and has a higher acid
consumption rate and thus requires more sulfuric acid than hydrofluoric acid.
[31]
In California there are currently two refineries that use modified hydrofluoric acid (MHF), ExxonMobil’s Torrance
refinery and Valero’s Wilmington refinery. MHF is highly concentrated hydrofluoric acid (70% - 90%) that is modified
with an additive which reduces the acid’s vapor pressure and lowers the probability of forming a dense vapor cloud.

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However, excess additive will damage the production of high octane fuel and the effectiveness of the additive’s ability to
reduce HF’s vapor pressure is uncertain.
2.3.2 Etching and Microfabrication
[6],[23],[30]
In the microelectronics industry, HF-based solutions are used extensively for wet etching of SiO2 or Si3N4, a
chemical process which is used to fabricate integrated circuit wafers and micro machines. Due to the unique structure of
silicon dioxide (SiO2), hydrofluoric acid is the only chemical that reacts with SiO2 at a high rate at room temperature. This
property of HF was first used to process, dissolve and clean silicate glasses. Diluted HF solutions and enhanced HCl/HF
solutions are also used for related, special applications.
Besides etching glasses and micro machines, hydrofluoric acid, due to its moderate reactivity towards many metals, is used
to etch transition metals, commonly aluminum, titanium, and their alloys. The etching process is very similar to that of
silicon dioxide, with additive chemicals such as nitric acid to eliminate generation of hydrogen gas and control reaction rate.
The final buffered HF solution is 3% to 10% concentration of HF.
2.3.3 Organo-fluorine Compound Production
[23],[29],[36]
Organo-fluorine compounds have many applications in the pharmaceutical industry. The synthesis of organo-
fluorine compounds involves the process of fluorination, a process in which fluorine is introduction into organic compounds
by forming carbon-fluorine (C-F) bonds. The C-F bond is the strongest single bond in organic chemistry and high desirable
in this application. Direct fluorination using gaseous fluorine is a difficult and expensive route. On the other hand, hydrogen
fluoride is an inexpensive and readily available commercial product, and its compound form of fluorine ion makes it an
attractive fluorinating agent.
The two widely used fluorination methods are electrochemical oxidative fluorination and halogen exchange fluorination. In
electrochemical fluorination, a HF containing solution is electrolyzed at about 5V near 0 °C producing the fluorinated
organic compound. Halogen exchange, as its name suggests, is the substitution of fluorine into other halogens in the existing
carbon-halogen bonds, thus producing carbon-fluorine bonded compounds. This process is industrially important in the
manufacture of refrigerants such as Freon. HF is the source for many other organofluorine compounds such as Teflon,
fluorocarbons, and fluoropolymers.
3. Methods and Procedure
The first step of this report was to perform independent research on the different aspects of the bill, the chemical properties
of HF, the ExxonMobil incidents, standard handling procedures of HF, current regulations regarding HF, and other
chemicals similar to HF. A wide variety of sources were used when conducting this research, such as the EPA and historic,
industrial reports and studies on HF.
Meanwhile, contact was established with some companies in the San Diego area that use HF through the assistance of Jack
Monger of the IEA. Specifically, Randy Skow of the Environmental Health & Safety Department (EH&S) at Air Products
and Chemicals (Carlsbad, CA), and Rick Siordia and Paul Johnson of the EH&S Department at UTC Aerospace Systems
(Chula Vista, CA) were contacted. Site visits with these companies were scheduled and conducted, and the findings of these
visits are discussed later in this report.
4. 2015 ExxonMobil Incidents propagated AB-1759
Since 1979, the Torrance refinery has been involved in over 80 incidents involving HF and it has had 22 incidents involving
hydrofluoric acid since 2010. (Section 1.d) The most recent events at the refinery were in Feb. 2015 and Sept. 2015. The
Feb.2015 incident was an explosion that nearly missed hitting a tank containing thousands of lbs. of high concentrated
(>70%) hydrofluoric acid. It was categorized as a serious near-miss and would have been catastrophic to the surrounding
communities if a hydrofluoric vapor cloud had formed. The Sept. 2015 incident involved a faulty equipment piece that

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contributed to the slow leak of modified hydrofluoric acid while the containment tank was under a refill operation.
ExxonMobil at the time owned the Torrance refinery (it was sold to independent refiner PBF Energy on Sept. 30, 2015).
4.1 Torrance Refinery Explosion
[29], [35]
On February 2, 2016, California’s Assembly Bill AB 1759 was drafted and proposed in response to the recent events
that took place at ExxonMobil’s Torrance refinery last year. On February 18, 2015, an explosion at the refinery caused a
piece of equipment weighing approximately 80,000 pounds to be sent flying over 100 feet and landing a few feet away from
a tank containing hydrofluoric acid. If released, the hydrofluoric acid could have formed a vapor cloud of toxic gas that
could travel for miles, possibly injuring or killing the more than 200,000 residents that live within a three-mile radius from
the facility. The blast injured four workers and was categorized as a serious near miss that could have been fatal to nearby
communities. The blast was so strong, it registered a 1.7 on the Richter scale. The U.S. Chemical Safety Board said that
there are 333,000 residents, 71 schools, and eight hospitals within a three-mile radius from the refinery. The blast dispersed
large quantities of catalyst dust up to a mile away from the facility. Vanessa Allen Sutherland, chairperson of the Chemical
Safety Board said
“After hydrofluoric acid vaporizes, it condenses into small droplets that from a dense low-lying cloud
that will travel for several miles and cause severe damage to respiratory system, skin, and bones, potentially
resulting in death.” [29]
The events leading up to the explosion began on February 12, 2015 when workers noticed problems with the expander, a
part of the fluid catalytic cracking unit (FCCU), and set the FCCU in idle condition. With the FCCU shut down, steam was
forced into the reactor to prevent hydrocarbons from flowing back into the main distillation column. On the morning of
February 18, 2015, steam was escaping through an open flange on the expander, which prevented operators from continuing
maintenance work. The steam traveled through a leaking slide valve connected to the reactor. An outside supervisor reduced
the amount of steam flowing into the reactor so that work could continue, however, the workers were unaware that
hydrocarbons were leaking into the main distillation column from interconnected equipment. The hydrocarbons escaped
through the open valve and into the refinery’s electrostatic precipitator (ESP), accumulating inside the ESP igniting the
hydrocarbons and causing the explosion.
4.1.1 Torrance Refinery Explosion Investigation
[3], [29]
The U.S. Chemical Safety Board (CSB) is an independent federal agency responsible for investigating serious
chemical accidents. The agency does not issue citations or fines but focuses on making safety recommendations to
companies, industry organizations, labor groups, and regulatory agencies such as Occupational Safety and Health
Administration (OSHA) and the U.S. Environmental Protection Agency (EPA). The board members are appointed by the
President and confirmed by the Senate. The CSB’s investigations analyze all aspects of the chemical accident, including
physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management
systems.
Following the February 18, 2015 accident, the CSB had conducted an ongoing investigation regarding the series of events
that led to the explosion and found several safety management deficiencies that led to the accident. The CSB found that one
of the pieces of debris hit scaffolding in the refinery’s alkylation unit and was close to hitting a tank filled with tens of
thousands of pounds of HF. CSB investigators discovered that ExxonMobil prematurely granted permission for the FCCU
to be operational by neglecting several existing procedures. ExxonMobil bypassed the existing procedures by using a
document called a variance, a written temporary deviation from normal operating procedures. However, the variance used
was created in 2012 to address problems with the expander and CSB investigators found that ExxonMobil had not conducted
a management of change review before implementing the outdated variance even though conditions for the FCCU had

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changed over the previous three years. Exxon Mobil also performed inadequate process hazard analyses that could have
identified more effective safeguards against the flow of hydrocarbons, such as blind or de-inventorying the main distillation
column. Investigator-in-charge, Mark Wingard said,
“Although our investigation found two different process hazard analyses that considered a combustible
mixture igniting in the electrostatic precipitator, no effective safeguards were implemented at the refinery to
mitigate this threat.” [21]
If ExxonMobil had executed proper procedure the accident would likely have not occurred. ExxonMobil claims that the
accident had no potential risk to the surrounding community members.
4.1.2 Management of Change Review
[3], [29]
A Management of Change review is a practice used to establish that safety, health, and environmental risks are
contained when a company makes changes in their facilities, documentation, personnel, or operations. In August 2001, the
CSB released a safety bulletin on management of change and its useful and beneficial practice to ensure that safety, health,
and environmental risks are controlled. The failure to conduct a Management of Change review or perform hazard analysis
is similar to other CSB refinery investigations, including the fire at the Chevron Refinery in Richmond, California on August
6, 2012. The Chevron incident was more serious in that the fire endangered 19 workers and sent more than 15,000 residents
to the hospital for medical attention. The conclusion of their Chevron investigation, the CSB recommended that substantial
changes need to be implemented to the way refineries are regulated in California. Chairperson Sutherland said,
“The CSB is continuing to advocate for its process safety management recommendations and monitor
developments in California…the actions being taken in the state are some of the most substantive safety
improvements happening the United States right now.”[25]
4.2 Response to the February Explosion
[1]
On Aug. 13, 2015, Cal/OSHA cited ExxonMobil for 19 alleged violations, totaling $566,600, after an investigation into
the Feb. 18, 2015 explosion at the Torrance facility. The investigators concluded that the management failed to take action
and were aware of the hazardous conditions at the fluid catalytic cracker unit, the unit that had exploded. The investigators
said that as far back as 2007, the Torrance refinery had identified flammable vapor leakage into the precipitator, but “failed
to correct the danger”. A half-dozen of the violations were categorized as serious-willful because ExxonMobil intentionally
failed to comply with state safety standards. Each serious-willful violation came with a proposed $70,000 penalty.
Cal/OSHA also cited ExxonMobil for 12 serious violations, ranging from $7,200 to $21,600 each.
4.3 Hydrofluoric Acid Leak at the Torrance Refinery
[9], [12]
On September 6, 2015 at 2:35 a.m., a leak of modified hydrofluoric acid was discovered at a rate of 10 drops per
minute, unrelated to the explosion in February. The leak occurred from a 3-inch nozzle during a routine transfer as a truck
unloaded HF into a containment vessel at the facility. The temperature and surrounding conditions of the leak would not
have caused the HF to form a dense vapor cloud. Torrance Assistant Fire Chief Martin Serna said that the leak was fixed by
6 p.m. Sunday, meaning that the leak occurred for over 16 hours. Firefighters handled the situation safely by depressurizing
the vessel and neutralizing the spill with water. The Torrance Fire Department said that the safety action resulted in a reading
of zero parts per million of HF acid 2 feet from the leaking vessel. ExxonMobil’s spokeswoman Gesuina Paras said,

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“The amount of material leaked was significantly below quantities required to be reported to
regulatory agencies. However as a matter of practice, ExxonMobil notified the Torrance Fire Department
and South Coast Air Quality Management District…there was no impact to people, the environment or the
community.” [9]
Despite the ExxonMobil’s reassurance, Jim Tarr, president of Rolling Hills Estates-based Stone Lions Environmental
Corporation, with almost four decades of experience evaluating toxic chemical and air pollution exposure said that this
should be a wake-up call.
“The use of modified hydrofluoric acid at the ExxonMobil refinery needs to be discontinued as soon
as possible…everyone needs to understand these hydrofluoric acid releases can occur without notice and the
next one may be much more substantial than this one.” [12]
4.4 Response to the Hydrofluoric Acid Leak
[2], [12]
The Torrance Fire Department disclosed that ExxonMobil failed to follow the established safety procedures to notify
the Fire Department of the Sept. 6, 2015 hydrofluoric acid leak. In a Sept. 10 letter to refinery manager Brian Ablett, Deputy
Fire Chief David Dumais wrote,
“It appears to the Torrance Fire Department that the on-duty safety advisor did not follow the
Reporting Protocol Flowchart – Leak/Spill/Release section as established and agreed upon by Torrance Fire
Department and ExxonMobil Torrance Management. Since the site safety advisor found an active modified
hydrofluoric acid (MHF) leak and the MHF alarms had been activated, the site safety advisor should have
notified fire dispatch for a hazardous materials response.” [12]
The Torrance Fire Department reported that the on-site safety advisor sent an email notifying the Fire Department of the
leak approximately 30 minutes after the leak had been detected. Approximately six hours later, 8:38 a.m., the on-site safety
advisor made a phone call to the on-duty platoon commander to notify him of the MHF spill. The Torrance Fire Department
requested that ExxonMobil establish an “action plan” to improve the protocol of reporting incidents at the facility for the
well-being of the community.
On March 4, 2016, Cal/OSHA issued three citations totaling $72,120 to ExxonMobil Refining & Supply Company for
failure to repair faulty equipment at its Torrance refinery for four years. This was found after the state agency’s investigation
following the HF leak at the refinery’s alkylation unit on Sept. 5, 2015. Investigators discovered the leak was due to a
temporary clamp that was installed on a 3-inch nozzle flange that was also related to an earlier leak in 2011. Cal/OSHA
Chief Juliann Sum said,
“This is a case [where] a minor repair could have prevented workers at this refinery from exposure
to a life-threatening acid…these citations and penalties are a wake-up call that refineries must follow strict
safety protocols to protect their employees.” [2]

Page 12
Cal/OSHA said that the three citations included one willful-serious, where the employer was aware of the hazardous
condition and did not take reasonable steps to address it. The other two general citations were for ExxonMobil’s alleged
failure to conduct a hazard analysis and identify and fix the 2011 leak. Cal/OSHA’s news release said
“ExxonMobil mitigated the leak caused by the faulty clamp within 48 hours of the release. The
company also removed tank 5C-31 from service, where the faulty nozzle was attached, to make repairs. Before
ExxonMobil was allowed to restart operations in January, a complete inspection of the alkylation unit was
conducted to ensure there were no additional leaking flanges or nozzles.” [2]
4.5 ExxonMobil Torrance Refinery Aftermath
[11]
The recent events at the Torrance refinery has had several impacts on California. The most important is that it has re-
opened a discussion for an outright ban on the use of hydrofluoric acid. Led by the grass-roots Torrance Refinery Action
Alliance, Torrance residents and communities in the South Bay are concerned that they are living in a life-threatening area,
an area where a worst-case scenario at the Torrance refinery could be fatal to the over 250,000 surrounding residents.
Since the explosion and at the time of this report’s writing, the Torrance refinery had been operating at 20% capacity which
has had an impact on California’s gas prices. At 100% operations, the refinery is responsible for supplying the state with
10% of its gasoline supply and more specifically 20% of Southern California’s refined gasoline supply. Gasoline prices are
expected to decrease after the South Coast Air Quality Management District (SCAQMD) ruled to allow ExxonMobil to
restore the Torrance refinery to full operations. In fall 2015, ExxonMobil sold the refinery to independent oil refiner, PBF
Energy, who will be taking over the facility once ExxonMobil restores the facility to fully operational.
Because of ExxonMobil’s numerous incidents with HF, the Torrance Refinery Action Alliance, government representatives,
and community members have petitioned for an outright ban on Torrance and Wilmington’s facility use of HF. HF is not
only dangerous in the production process but is also considered by the FBI to be a potential chemical weapon for terrorists
to utilize. Large tanks are transferred by trucks across highways and streets to these facilities, often without any security
guarding their pathways.
[9], [31]
PBF Energy has had an excellent track record handling HF, with zero incidents in the last 5 years during their
operations. A ban on the use of HF will force the Torrance refinery and Wilmington refinery to either shut-down or switch
to sulfuric acid. The switch to sulfuric acid is a very expensive process as multiple equipment will have to be replaced, a
process that will cost approximately $100 million dollars according to a 1988 report. This process would also use 100 times
more sulfuric acid than HF. It is not known whether the sulfuric acid substitute produces the same octane content and refined
gasoline that made the modified HF so desirable. Because of state regulations, California’s gasoline supply is a unique blend
that is less harmful for the environment. If the Torrance refinery refuses to convert to sulfuric acid and shuts-down,
California will lose 10% of its refined gasoline supply plus the amount produced from the Wilmington refinery, possibly
resulting in even higher gas prices. Furthermore, sulfuric acid is a dangerous chemical as well and using 100 times more
acid needs to be considered if a switch is made.
[11], [29]
The risk from human error is prevalent in all industries, but is magnified when dealing with volatile combustible
reactions and life-threatening acids such as HF. The CSB did not propose a ban on hydrofluoric acid in oil refineries, but
believe that the accidents that have happened in the past could have been avoided with a more analytical and structured
approach that could have helped to prevent or mitigate the effects of these accidents.

Page 13
5. Industry Analysis
5.1 Standard Handling and Emergency Procedures
Both anhydrous and aqueous solutions of hydrofluoric acid require immediate and specialized medical treatment, and as
such all facilities working with hydrofluoric acid must have a rigorous set of safety measures to minimize the chance of
injury, and to reduce damage once exposure has occurred. The following safety measures are professional-recommended
and should already be in practice for any facility meeting current legal mandates, such as the Federal Risk Management
Plan, discussed in Section 6. With that being said, such mandates only provide a minimum safety benchmark for any facility
working with HF, and many facilities require much stricter and more in-depth protocols.
[17]
Any facility, whether it be for industrial or academic purposes, must establish a Standard Operating Procedure (SOP)
specifically for hydrofluoric acid. All facilities which have met state requirements to use HF on-site should already have
one of these. Additionally, HF should only be used in specific and designated areas, which have essentials such as the SOP,
HF MSDS, and a first-aid and spill kit, which contains equipment that shall be discussed later in this section.
[13]
Any individual working with HF must undergo sufficient safety training. The training should include a description of
the medical hazards of HF, how to recognize exposure symptoms, and initial first aid measures to take, along with a
demonstration of such. Additionally, it should include a demonstration on how to properly put on adequate personal
protective equipment (PPE), as well as cleaning and decontamination procedures. Adequate PPE varies immensely
depending on the amount, form, and concentration of HF being used. In a small laboratory setting with no vapor release, it
entails splash-proof goggles and a plastic face shield, and no contact lens if possible. Double-gloving is recommended, and
neoprene or Polyvinyl chloride [PVC] gloves should be worn over nitrile gloves, and replaced at first sign of
contamination. Additionally, and acid-resistant apron should be worn and all other skin covered. If fuming is a concern,
and above 40% concentration it is, proper respirators are necessary, and OSHA lists the permissible exposure limit as 3
ppm. Lastly, eyewash stations and showers must be immediately accessible. Sufficient safety precautions such as the ones
listed above are required by law, such as California Accidental Release Prevention (CalARP), discussed in Section 6.
[27]
The speed at which exposure to hydrofluoric acid can be detected depends upon the strength of the solution. Exposure
to a solution with concentration above 50% will cause immediate and sharp pain. Between 20 to 50% concentration, pain
may not occur for one to eight hours, and below 20% concentration, symptoms may take as long as 24 hours to manifest.
These time estimations are applicable for skin, dermal, and respiratory exposure.
Though the exact procedure to treat exposure depends on the route, many of the steps that ought to be taken are applicable
for multiple routes, and skin exposure will primarily be discussed in this report. However, any facility using HF must have
explicit instructions for medical treatment for skin, eye, oral, respiratory, and nail exposure.
[27]
The first step once exposure occurs is to immediately flush the area with water with using either a hand washing station
or a safety shower and remove all clothing. Calcium gluconate 2.5% gel should be applied to the afflicted areas, and can be
massaged into the skin while flushing with water. Be liberal with the gel and reapply every 15 minutes, and continue to do
so while medical personnel are contacted. Despite the severe pain of HF burns, it is critical that no pain-reducing drugs are
given, as relief of pain is the primary indicator of success of treatment. For deeper burns, injection of 2.5% aqueous calcium
gluconate with a needle may be necessary. Do not use more than 0.5cc per square centimeter initially, and leave this
procedure to a physician only. For very severe burns (covering more than four square inches), the individual ought to be
transported immediately to an ICU. Any medical personnel must use minimum PPE as well (such as gloves) to prevent the
spread of hand burns. If severe exposure occurs, medical personnel must also be aware of hypocalcemia.
5.2 Air and Chemical Products
The Air Products & Chemicals facility in Carlsbad, CA, is responsible for the manufacture of various high purity chemicals
which are crucial in the manufacture of semiconductors. Hydrofluoric acid is used because it is exceptionally good at
cleaning quartz, one of the primary components of the containers used to ship the chemicals. The chemicals are of an ultra-

Page 14
high quality, and thus must be shipped in ultra-clean containers, and HF is the only chemical which has been able to provide
a satisfactory level of cleaning. While the company has done minimal research into alternative chemicals, the semiconductor
industry is notorious for being highly resistant to change. A change in procedure (such as using a different cleaning
chemical) would be met with disapproval from their customers, and a significant loss of business would be expected.
5.2.1 Concentration/Amount stored and used
Air Products initially purchases reagent-quality HF in 1 gallon containers, in its aqueous form at 49% concentration. Air
Products does not use anhydrous HF. Only 12 gallons are stored on-site at a time, which are stored in a standard corrosive-
resistant cabinet contained in another secondary container. This HF is then used in a mixing process, which dilutes it down
to either a 5% or 10% batch concentration, depending on which cleaning station it will be used at. The machines at these
stations are also secondarily contained and the cleaning process for the primary station is automated, minimizing contact
with HF. Once the batch is made, it is monitored on-site until the quality deteriorates sufficiently that it needs to be replaced.
5.2.2 Safety Procedure
Air Products has an extensive list of safety protocols for managing HF. An eye washing station and a shower are seconds
away from the cleaning machines, as are spill and first aid kits. Proper PPE included goggles, protective shield, and apron,
and the floor is corrosive-resistant. In case of emergency, the company Emergency Action Plan calls for the room to be
immediately isolated and automatically contacts the fire station, which has recorded arrival times of less than 5 minutes
from training exercises. Additionally, there are 16 trained emergency responders on-site.
There are several administrative procedures in place in order to prevent an accident from occurring in the first place. The
laboratory undergoes monthly inspections, and each piece of equipment has its own preventive maintenance plan. Air
Products also undergoes an in-company audit every 3-5 years which mimic state and federal inspections. They follow state
regulations regarding the discard of the HF batch.
5.2.3 Bill’s Effect on Industry
According to Mr. Skow, AB-1759 would not have a large impact on the manufacturing process as there is usually less than
250 gallons stored on-site. However, it could affect the site under certain conditions. Specifically, after a batch is replaced
but before the old batch is discarded, the 250-gallon threshold may be broken. However, the HF stored is all aqueous and
low in concentration, thus the release of a large vapor cloud is not possible. Mr. Skow mentioned that a major fault in AB-
1759 was that there was no specific mention of concentration levels for the HF ban. He felt that this was an important
oversight because there is a considerable difference between high and low concentrations of HF.
5.3 UTC Aerospace Systems
UTC Aerospace Systems manufactures aerospace and defense products. One of the key goals in aerospace product
manufacturing is to reduce weight of the components. To achieve this, UTC Aerospace Systems uses hydrofluoric acid to
etch metals to reduce mass while maintaining structural and mechanical integrity. Currently no machinery is capable of
producing the same results and is as effective and efficient as chemical etching.
5.3.1 Concentration/Amount stored and used
HF is never stored or produced in massive quantities on site. Approximately 500 lbs. of ammonium bifluoride, a salt form
of fluoride, is stored on site instead. Nitric acid is added and reacts with the salt to produce HF at a concentration of less
than 20%, far below the vapor generating concentration around 40%. Raw chemicals at UTC Aerospace Systems, including
ammonium bifluoride, are based on an order-delivery schedule within a few days. Any shipment of new chemicals must go
through an extensive review and purchase procedures by scientists and company managers. Upon delivery, each shipment
is tagged with a unique label so that they can keep track of how the chemical is used and the quantity used.

Page 15
5.3.2 Safety Procedure
The HF-producing reactions take place in air-exposed tanks which are housed in a large warehouse with a controlled air
flow. Operators work 3 ft. away from the tanks, and fans blow tank fumes away from the operators to avoid any inhalation
of chemical vapors. These fumes (if any) are removed from the warehouse by the air flow, which then undergo treatment
by a scrubber to clean the air before it is released. The chemical levels of the air are rigorously monitored to ensure they are
below all state and federal regulations before leaving the facility. Tank reactors are placed in secondary containment, to
guarantee any spills or overflow will be diverted back to the tanks by gutters. In case of emergencies, eyewash and shower
stations are in close proximity, and are able to be reached within 10 seconds, complying with government regulation.
Emergency alarms are installed on site, and an emergency response team is prepared to handle any spills.
5.3.3 Bill’s Effect on Industry
According to Mr. Siordia and Mr. Johnson, Bill AB-1759 will have minimal effect on their company's manufacturing and
handling procedures since hydrofluoric acid is an intermediate in the production process and is never stored or produced
in large quantities. Processes that require large amount of hydrofluoric acid have been relocated out of California.
However, Mr. Siordia and Mr. Johnson, along with Mr. Skow from Air Products and Chemicals, all noted that the lack of
specification on concentration or vapor pressure of hydrofluoric acid is problematic because properties of HF differ
largely depending on concentration. Mr. Johnson also suggested that there have are numerous and sufficient safety
regulations and requirements already in place regarding the usage of hydrofluoric acid, and the right path is to more
effectively enforce these regulations rather than creating more.
6. Strong Regulatory System in Place
Hydrofluoric acid, along with numerous other dangerous chemicals, are heavily regulated by multiple agencies and
regulations. Discussed below are the Environmental Protection Agency (EPA) the Federal Risk Management Plan (FRMP),
the California Accidental Risk Prevention Program (CalARP), and the Occupational Safety and Health Administration
(OSHA).
6.1 Environmental Protection Agency
[19]
In a 1993 study, the Environmental Protection Agency (EPA) conducted a comprehensive study about the use of
hydrofluoric acid in industry, specifically oil companies. Congress required the EPA to conduct the study in order to identify
potential hazards to public health and the environment by considering the worst-case accidental releases, and to make
recommendations for reducing the hazards.
The EPA regulated HF under several regulations authorized by the Comprehensive Environmental Response,
Compensation, and Liability Act (CERCLA), Title III of the Superfund Amendments and Reauthorization Act (SARA) of
1986 and the Resource Conservation and Recovery Act (RCRA). HF has also been regulated by the Department of
Transportation (DOT) under the Hazardous Materials Transportation Act (HMTA) and the Hazardous Materials
Transportation Uniform Safety Act (HMTUSA).
The EPA study characterized how and where HF is produced and used in the United States. It identified the hazards that
were specific to those uses and processes and assessed the potential hazards to the public and the environment from potential
HF releases. The EPA’s analysis found that the greatest hazards of HF were associated with the manufacture and use of
high concentrated HF (>70%). HF has been heavily regulated under a number of U.S. statutes. An in-depth analysis can be
found in the 1993 study [16].
6.2 Federal Risk Management Plan
[28]
One of the current pieces of federal legislation that regulates HF is the Federal Risk Management Plan (FRMP) which
implements Section 112(r) of the Clean Air Act (CCA) amendments of 1990. This law allows the EPA to publish regulations
and guidance regarding chemical accident prevention at facilities that use certain hazardous substances. This info is used
by fire, police, and emergency response personnel in case of chemical emergencies

Page 16
6.2.1 Risk Management Plans
[28]
A RMP must address at minimum these three topics:
1. A Hazard assessment that details the consequences of an accidental release under a variety of conditions, including
worst-case scenarios, and an accident history dating back the last 5 years.
2. A Prevention program which includes safety precautions (such as a SOP), training measures, and facility
maintenance and monitoring.
3. An Emergency response program which includes emergency health care and employee training for informing
response agencies and the public in the case of an accident.
[19]
For HF, a RMP is only necessary for facilities that use HF at concentrations above 50%, and use enough HF to surpass
the 1,000 lbs. Threshold Quantity.
6.2.2 General Duty Clause
[26]
One aspect of Section 112(r) is the General Duty Clause (GDC), which recognizes that owners and operators of facilities
have a responsibility in managing any hazardous chemicals on-site. This responsibility includes: being aware of the hazards
of said chemicals and the consequences of a possible release, designing and maintaining facility safety in order to prevent
accidents, and minimizing the impacts if a release does occur.
With that being said, the General Duty Clause does not provide specific regulatory guidelines for meeting the above
requirements, and cannot be checked against any particular data sets. For example, the GDC does not specify the exact
manner in which an owner need to identify hazards and conclude the consequences of a release. Despite this, a hazard
assessment should include the different types, rates, and durations of potential chemicals releases by using modeling and
dispersion analytical techniques.
To meet the requirements of the GDC, all relevant industry codes and standards must be adopted, though these policies may
not always be enough to indicate a satisfactory attempt at meeting GDC guidelines. In such a case, a unique and tailored
accident prevention program may be necessary depending on the facility. Additional suggestions in meeting GDC
requirements can be found at the EPA website, and the link is provided in the References section (5). Section 113(b) allows
the EPA to require the implementation of these additional safety measures, and to assess penalties of up to $37,500 per day
for each violation.
6.2.3 FRMP Programs
As part of Section 112(r) of the CCA, some programs enacted by the EPA regarding chemical safety were implemented and
are as explained as following:
One of the programs is Chemical Safety Audits, which focuses on the prevention and mitigation of chemical accidents by
reviewing facilities’ programs. These audits are meant to provide compliance assistance towards GDC requirements.
However, a deficiency in these programs can also be cited as a violation of the GDC or overall risk management program.
Another is Accident Investigations, which ideally is able to determine the root cause or system failure that caused the
accident. This information can be used to reduce the likelihood of a recurrence and minimize the consequences if there is a
recurrence. These investigations are led by the Chemical Safety and Hazard Investigation Board, created by Section 112
(r.6) of the CCA.
Lastly, there are RMP Audits. These audits focus on assessing a facility’s RMP for hazard assessment, prevention, and
response. If found necessary, the EPA may require RMP modifications for program improvements.

Page 17
6.3 California Accidental Release Prevention (CalARP)
[7]
The California Accidental Release Prevention Program (CalARP) includes the federal Accidental Release Prevention
Program with additional specifics to the state’s Health and Safety Code (HSC). The purpose of the program is to prevent
the accidental releases of regulated substances, such as HF.
Any stationary source that exceeds the threshold quantity of a regulated substance may be required to develop and submit
a risk management plan (RMP) to determine the potential for and impacts of accidental releases. According to Section
2745.3, the RMP shall include the (1) accidental release prevention and emergency response policies at the stationary source,
(2) the stationary source and regulated substances handled, (3) the general accidental release prevention program and
chemical-specific prevention steps, (4) the five-year accident history, and (5) the emergency response program and the
planned changes to improve safety. In addition, the owner needs to submit a worst-case scenario and analysis on the
Prevention Program for each Program 1, 2, and 3 process and extensive data regarding the chemical such as release rate,
release duration, etc. The data required can be found in Section 2745.4-2745.11.
6.3.1 Hazards Assessment & Five-year Accident History
[7]
Section 2750.1 - Section 2750.9 discuss the requirements behind the Hazards Assessment and the five-year Accident
History section in the RMP. The assessment must include analysis parameters such as wind speed, ambient
temperature/humidity, height of release, etc. The worst-case scenario must define the largest impacted radius from the center
at the point of release with the population defined as the residential population plus the presence of institutions (such as
schools, hospitals, long term health care facilities, child day care facilities, and prisons), parks and recreational areas, and
major commercial, office, and industrial buildings.
6.3.2 Training, Maintenance, & Compliance Audits
[7]
Section 2755.4 – Section 2755.6 discuss the requirements behind the Training, Maintenance and Compliance Audits for
the RMP. The owner is responsible for ensuring that each employee has been tested and is competent in the operating
procedures for their designated operation. At least every three years refresher training must be provided to each employee
operating a process. The owner must ensure that the operators are trained in any updated or new procedures.
The owner must train each employee involved with maintaining the mechanical integrity of the process equipment. Any
maintenance contractor must ensure that each contract maintenance worker is trained to perform the maintenance
procedures. Each process equipment must be inspected frequently to follow generally accepted good engineering practices.
The frequency of the inspections should be consistent with the manufacturer’s recommendations.
Every three years, the owner must submit a compliance audit that certifies that they have followed the procedures and
practices developed mentioned in the previous sections. The audit is conducted by at least one person knowledgeable in the
process. The owner should hold the two most recent compliance audit reports.
6.3.3 Contractors
[4]
Section 2760.12 states that the owner shall obtain and evaluate information regarding the contractor’s safety performance
and programs. The owner should review that each contract employee follows the safety rules and follow safe work practices.
6.4 Occupational Safety and Health Administration
[19]
The Occupational Safety and Health Administration (OSHA), which is the primary federal agency regarding safety and
health legislation. OSHA sets a number of industry standards, such as:
(1) What information employers must provide employees regarding hazardous chemicals (Hazard Communication
Standard
(2) What personal protective equipment employers must prove and how often it must be inspected (Occupational
Safety and Health Act)
(3) Air contaminants exposure thresholds, stated earlier as 3 ppm for HF (Occupational Safety and Health Act)

Page 18
The OSHA Process Safety Management Standard is a set of requirements which is intended to minimize the consequences
of releases of hazardous chemicals, thereby protecting employees. It includes a written safety compilation, which includes
information on subjects such as chemical hazards and the equipment being used to handle said chemical. Another component
is a process hazards analysis which must be conducted every 5 years. It is a thorough review of potential scenarios of
something gone wrong, and what safeguards are in place in case any such scenario arises. Other elements are a SOP,
employee hazards training, pre-startup equipment safety reviews, and regular mechanical maintenance.
7. Relationship to Hydrochloric Acid
[20]
One of the most commonly used chemicals in the world, perhaps even more so than hydrofluoric acid, is hydrochloric
acid. Similarly, to HF, HCL is extremely dangerous, with the maximum health and exposure hazard rating possible.
According to OSHA, HCL’s Permissible Exposure Limit is 5 ppm, only slightly above HF’s Limit of 3 ppm. Many of the
standard handling and emergency procedures for HF are applicable for HCL, such as extensive PPE including (but not
limited to): a face shield, acid-resistant apron, gloves, and respirator if using high enough concentrations as to cause fuming
(discussed more below). If HCL makes eye or skin contact, or is inhaled or ingested, it is HIGHLY suggested to seek
medical attention immediately. Specific treatment can be found in the MSDS, which should be immediately available at
any facility handling HCL.
[21]
Another way in which HCL is similar to HF, and what makes it especially relevant to this report, is that HCL is produced
at varying concentrations depending on the manner in which it is used, and has different handling protocols depending on
this concentration. HCL becomes more hazardous as concentrations increase simply due to HCL’s corrosive nature, but
what makes higher-concentration HCL especially dangerous is the fact that its evaporation rate also drastically increases.
This drastic increases begins around 15% concentration (depending slightly on pressure), reaching a near 100% evaporation
rate by 39% concentration (and at that point, fuming profusely). Without adequate ventilation or a respirator, inhalation is
extremely likely.
[19], [22]
HCL has household purposes, largely cleaning, and these solutions are usually between 10-12%, and often diluted
even further. At higher concentrations, it is used for the production of chlorides, fertilizers and dyes, and has uses in the
photographic, oil, and rubber industries. This bulk, industrial-grade HCL is usually between 30-35%, though it can be
produced at up to 38% concentration. While it is possible to produce solutions with concentrations slightly above 38%, the
solution evaporates so quickly that additional storage and handling requirements are necessary. Under the Federal Risk
Management Plan, any facility handling over 15,000 lbs. of HCL at a concentration above 37% must create an RMP.
[24], [19]
Hydrochloric acid is also produced in an anhydrous form, hydrogen chloride gas, a clear colorless gas composed
100% of hydrogen chloride. When exposed to air, it reacts quickly to water moisture in the air and strongly fumes. It can
cause severe respiratory tract, eye, and skin burns. Again, handling procedures and exposure procedures can be found in the
MSDS and are similar to aqueous HCL, though are stricter, especially in regard to respiratory protection. An RMP is
necessary under the FRMP for any facility handling over 5,000 lbs.
The purpose of this brief discussion of HCL was to demonstrate that there are already chemicals which have different
standards and protocols depending on the concentration and form of the chemical besides HF. As discussed above, HCL is
a hazardous enough chemical to be heavily federally monitored. However, HCL in a low concentration form is not only
able to be freely purchased, but is regularly used in common household products. Clearly, the dangers these chemicals pose
have already undergone extensive evaluation, yet have been deemed too valuable to outright ban, and HF is no exception.
Furthermore, HCL isn’t under consideration from this bill despite the fact that it fumes at considerably lower concentrations
of HF, and from the bill it appears that large-scale fuming is the primary concern regarding HF’s use. While HF and HCL
undoubtedly pose different dangers, adhering to concentration-based standards for HF would be in no way unprecedented.
8. Findings and Recommendations
Hydrofluoric acid is an extremely dangerous and threatening chemical. According to the U.S. Chemical Safety Board’s and
Cal/OSHA’s investigative reports, the accidents at the Torrance facility could have been avoided if management had

Page 19
followed proper protocol. Instead, the facility manager used an outdated document to avoid existing safety industry
standards and regulations. The CSB concluded its investigative report by saying that substantial changes need to be made
in how refineries are regulated.
Our first recommendation, which is less drastic than this bill, is to more stringently enforce the current federal and state
laws regarding HF. As discussed earlier, there is already an extensive network of standards and regulations for facilities
using HF. The current regulations, when properly followed, tremendously reduce the likelihood of an accident, as seen with
UTC Aerospace and Air Products & Chemicals, which have not even had a minor HF accident affecting the public. On the
other hand, the Torrance refinery incident arose because current standards and regulations were not being adhered to by
management. We propose that to ensure these regulations are followed, the penalty fines associated with violations be
substantially increased. These fines can then be used to offset the costs of the additional and stricter inspections incurred in
this process.
The formation of a HF vapor cloud is possible in large, highly concentrated quantities that are present in large industrial
facilities such as oil refineries. Such a large, dense vapor cloud over a residential area would be absolutely catastrophic, and
is a situation that absolutely must be avoided. However, AB-1759 in its current form is not the optimal way to ensure this.
Relatively dilute HF with concentrations less than 40% do not produce significant vapor concentrations unless superheated
and placed under large amounts of pressure, conditions typically only found in oil refineries or similarly large facilities.
Under standard conditions, such as those found in university laboratories, aqueous HF will begin to fume at concentrations
above 40%, but will not form a dense cloud. Aqueous HF concentration may increase until it reaches its maximum saturation
at 70% (under standard conditions), at which point it is at its most volatile state and reaches maximum fuming. It is at this
concentration and under high pressure conditions that there is a higher probability for the formation of a dense vapor cloud
if a HF release occurs.
We strongly recommend that the bill recognize the difference in threat level that HF poses at difference concentrations, as
is done with other chemicals. The hazard posed by a 30% concentration HF solution cannot reasonably be compared to a
70% concentration HF solution. As such, we propose that the bill follow federal guideline practices and focus on facilities
that handle HF concentrations over 50% such as oil refineries. Due to its effect on fuming, the establishment of a vapor
pressure threshold should be considered as well. Many companies in California, such as Air Products and Chemicals and
UTC Aerospace, responsibly use HF at concentrations less than 50% at standard air pressures, and their working conditions
present minimal public safety threat. To force these companies to halt the use of HF would be catastrophic to California’s
economy, yet would not provide the public safety benefit that the bill seeks.
If our other proposals are not to be followed, our final proposal (and as a last resort) is that the bill should extend the time
period before it goes into effect as to allow for additional time if it is going to force oil refineries to find an alternative to
HF to use in the alkylation process. The United Steel Workers Study has concluded that there are a few alternatives to HF.
The first, which replaces HF with sulfuric acid alkylation, has already been implemented in some refineries, though it has
its drawbacks. As discussed in Section 4.5, sulfuric acid is much safer than HF but it still poses serious hazards for workers,
the public and the environment, and is not for certain an effective alternative. Secondly is solid-acid catalyst alkylation
which has been studied and implemented by a few companies. Another is ionic-liquid alkylation, a process that has been
successfully developed and implemented in Chinese refineries and is in the pilot and production phase. The two processes
are much safer for workers and the public because of it does not use HF or sulfuric acid. However, more research and studies
must be conducted in order to determine if either are a reliable alternative and are able to meet California’s unique gasoline
blend regulation. With all factors considered, there is absolutely no way an alternative will be available by 2017.
Furthermore, any alternative will come at enormous costs, costs which could be enough to force the shutdown of refineries.
8. References
Bill Number AB 1759. Introduced by Assembly Member Rob Bonta. February 2, 2016.
[1] "Cal/OSHA Seeks Huge Penalties in Refinery Explosion - Cal-OSHA.com." CalOSHA Reporter RSS. N.d. [Accessed
April 26, 2016]. http://www.cal-osha.com/Cal-OSHA-Seeks-Huge-Penalties-in-Refinery-Explosion.aspx.

Page 20
[2]"Cal/OSHA Cites ExxonMobil for Unrepaired Leak at Torrance Refinery – Occupational Health &
Safety." Occupational Health & Safety. March 9, 2016. [Accessed April 25, 2016].
https://ohsonline.com/articles/2016/03/09/cal-osha-cites-exxonmobil.aspx.
[3] "CSB Safety Bulletin Says "Managing Change" Is Essential to Safe Chemical Process Operations."
U.S. Chemical Safety Board. August 28, 2001. [Accessed April 25, 2016]. http://www.csb.gov/csb-safety-bulletin-says-
managing-change-is-essential-to-safe-chemical-process-operations/.
[4] Dobis, Jonathan, Williams, Dana and David Bryan Jr." The Effect of Operating Conditions on Corrosion in HF
Alkylation Units". Inspectioneering Journal. May/June 2004. [Accessed May 18, 2016].
[5] Esteves, P. M., C. L. Araujo, B. A. Horta, L. J. Alverez, C. M. Zicovich-Wilson, and A. Ramirez-Solis. "The
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9. Appendix
[11], [12]
Tables taken from Honeywell MSDS safety sheets.

Investigation of HF acid in California regarding AB 1759

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