This advisory recommends ways Local Emergency Planning Committees (LEPCs) and chemical facilities can reduce
risks posed by the presence of hydrogen fluoride (HF) in their communities. Hydrogen fluoride, a strong inorganic
acid, is produced and used as a gas or liquid without water (i.e., in anhydrous form), or in a water (aqueous)
solution. The anhydrous form is potentially more hazardous than hydrogen fluoride in dilute water solutions,
because anhydrous hydrogen fluoride has greater potential for fuming and forming vapor clouds. If anhydrous
hydrogen fluoride is accidentally released, it may react with water vapor to form a white vapor cloud. Under certain
conditions, such a cloud has the potential to travel considerable distances close to the ground and pose a threat to
people in its path. EPA stresses that although mishandling of HF can cause harm, there is no cause for undue
alarm about its presence in the community when it is properly and safely managed.
Inhalation of hydrogen fluoride vapor, either in anhydrous form or from water solutions, can cause' irritation if the
exposure is mild (i.e., low concentration in air for a short time), or severe damage to the respiratory system or death
in the case of exposure to high concentrations. Contact with the liquid or vapor can severely burn skin, eyes, and
other tissue. Burns from hydrogen fluoride are particularly dangerous and require immediate and special treatment
by trained medical personnel.
The largest use of hydrogen fluoride is in the manufacture of fluorine-containing chemicals, particularly
chlorofluorocarbons (CFCs). Hydrogen fluoride may be used in some petroleum refinery operations, aluminum
production, nuclear applications, glass etching and polishing, and metal treating and cleaning.
Although major incidents involving hydrogen fluoride have been rare, one example was an accident at a Texas
petroleum refinery. A construction accident at an alkylation unit resulted in the release of 30,000 to 50,000
pounds of hydrogen fluoride and isobutane. The vapors migrated to an adjacent residential area. Eighty-five
square blocks and approximately 4,000 residents were evacuated. There were no fatalities. More than 1,000
residents went to three neighboring hospitals. Although about 100 were admitted, most of those reporting to
hospitals were treated on an outpatient basis. In some cases, there were reports of skin irritation and irritation
to the eyes, nose, throat, and lungs. Some vegetation in the path of the cloud was also damaged.
Federal Requirements:
Hydrogen fluoride's acute toxicity prompted EPA to
list it as an extremely hazardous substance (EHS),
with a threshold planning quantity (TPQ) of 100
pounds, under Section 302 of the Emergency Planning
and Community Right-to-Know Act (commonly
known as SARA Title III). OSHA's Process Safety
Management Standard, published February 24, 1992,
requires facilities with anhydrous hydrogen fluoride in
quantities at or above the threshold of 1,000 pounds
to implement process safety management to protect
employees by preventing or minimizing the
consequences of chemical accidents. In addition,
OSHA regulations require that facility employees who
could potentially be exposed to hydrogen fluoride in
any form be trained to handle and use it safely and to
recognize and deal with the potential hazards posed
by this chemical. EPA regulations required under the
Clean Air Act soon will require facilities with HF
above a threshold quantity to prepare risk
management plans; these plans will be provided to
LEPCs and the state.
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RECOMMENDED STEPS FOR LEPCS
Section 302 of SARA Title III requires LEPCs to
develop comprehensive emergency plans to address
facilities where hydrogen fluoride as well as other
EHSs arc present in excess of their threshold
planning quantities (100 pounds for hydrogen
fluoride). Because an accidental release of hydrogen
fluoride can pose a significant health and safety
hazard, EPA suggests that LEPCs take the following
steps:
Hazards Analysis/Hazard Identification:
Know which facilities produce or use hydrogen
fluoride. These facilities include:
- Chemical manufacturers (e.g.,
chlorofluorocarbons, fluorine, organic and
inorganic fluorine compounds, linear
alkylbenzenes);
- Petroleum refinery alkylation units;
- Aluminum producers;
- Pharmaceutical companies; and
- Uranium processors.
Facilities that produce or use water solutions of
hydrogen fluoride, which may be less hazardous
than pure hydrogen fluoride, particularly if the
solutions are dilute, include:
- Chemical manufacturers (e.g., some
inorganic fluorine compounds);
- Stainless steel producers;
- Manufacturers of metal products;
- Electronic equipment manufacturers;
- Transportation equipment manufacturers;
- Aerospace industry; and
- Glass manufacturers.
Know routes and methods of HF transportation in
the area.
Note: There are many other names for hydrogen
fluoride. Hydrogen fluoride without water may be
called anhydrous hydrogen fluoride; HF; AHF; HF-A;
hydrofluoric acid; hydrofluoric acid, anhydrous; or
anhydrofluoric acid. Water solutions of hydrogen
fluoride may be called hydrofluoric acid; hydrofluoric
acid, aqueous; hydrofluoric acid solution; aqueous HF;
HF 70% (or other concentration); hydrofluoric acid
70% (or other concentration); or fluorhydric acid.
HF Characteristics:
Be aware of the characteristics that make hydrogen
fluoride hazardous, including:
- It is highly toxic;
- Depending on temperature and
concentration, it may be highly corrosive
to many substances (e.g., dilute HF
attacks most common metals);
- It can become airborne if released above
its boiling point of 67° F; and
- Anhydrous hydrogen fluoride may form a
vapor cloud containing aerosol if released
under certain conditions. Depending on
the conditions, the cloud may travel
considerable distances while remaining
close to the ground.
Vulnerability Analysis:
Example exposure guidelines include:
- IDLH (30 ppm for 30 minutes) and
- ERPG-3 (50 ppm for 1 hour).
When modeling potential releases of hydrogen
fluoride, take into account its important
properties, such as possible behavior as a
dense gas (heavier than air), aerosol formation
(HF vapor and droplets), and reaction with water
vapor. In addition to including the chemistry of
HF in vulnerability analysis, it is important to
include other factors such as release rate,
release quantity, meteorological conditions, and
area topography.
Note that the physical and chemical behavior of
hydrogen fluoride is complex upon release and
models not designed to address this behavior
may provide inaccurate estimates of dispersion
and downwind concentrations.
Identify vulnerable populations in potentially high
concentration areas.
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Emergency Planning/Testing the Plan:
Review methods facilities use to detect and
respond to releases.
Engage in a dialogue with facilities regarding
methods for preventing accidental releases of
hydrogen fluoride and systems in place to reduce
the off-site risk if release should occur. On-site
means of reducing off-site risks may include
emergency transfer systems, water spray mitigation
systems, remotely-operated isolation valves, HF
detectors, and HF inventory reduction. Be aware
that the effectiveness of these methods may be site
specific. For example, reducing inventories could
possibly lead to an increase in transportation-
related risk.
Regularly exercise and review Title III plans to
ensure that facilities handling large quantities of
hydrogen fluoride are covered, and that emergency
response issues concerning possible releases of
hydrogen fluoride have been addressed. Consider
whether plans should include protection in place
and/or evacuation in case of a hydrogen fluoride
release.
Determine if the local emergency response plan is
consistent with the facility's response plan.
Ensure that local hospitals and physicians are
properly trained and prepared to treat victims of
hydrogen fluoride exposure; in particular, ensure
that they are aware of the special hazards of
hydrogen fluoride exposure and are equipped to
treat such exposure.
Right-to-Know/Risk Communication:
Inform the community of the potential hazards of
HF, as well as emergency response methods for
treating victims of hydrogen fluoride exposure.
Send a copy of this advisory to all fire
departments, medical facilities, and hydrogen
fluoride facilities in your LEPC jurisdiction, calling
their attention to the recommended steps for
facilities in the section below.
RECOMMENDED STEPS FOR FACILITIES
In cooperation with LEPCs and local response
officials, facilities should take the following steps:
Handling and Storage:
Protect HF-containing vessels and piping from
impact by vehicles, machinery, or falling objects.
Heavy objects should not be lifted over equipment
containing hydrogen fluoride if it is possible to
avoid doing so. If not possible, potentially affected
equipment should be emptied prior to the lift.
Ensure that all containers, piping, valves, and
fittings contacting hydrogen fluoride are
constructed of hydrogen fluoride-resistant
materials. These materials may include special
alloys (such as Monel), specially-treated metals,
corrosion-resistant substances such as Teflon, and
Hastelloy-B. Carbon steel is generally used for
anhydrous hydrogen fluoride. Hydrogen fluoride is
incompatible with glass, concrete, and other silica-
based materials. Even dilute solutions of hydrogen
fluoride should not be stored in glass containers.
In industrial use, anhydrous HF may contain some
water. Improper control of moisture may result in
accelerated corrosion.
« Carry out regular inspections of equipment used
for hydrogen fluoride (including transfer hoses) for
thickness and cracks, fractures, or defects due to
corrosion or mechanical stress. Include welds in
the inspection.
e Refer to Department of Transportation (DOT)
regulations for shipping, packaging, marking, and
labeling requirements.
Employee Safety:
o Ensure that adequate training is provided to all
facility employees concerning the safe handling,
storage, and use of hydrogen fluoride.
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Ensure that adequate training is provided to all
employees concerning the need to wear personal
protective clothing and equipment that is
appropriate to the task for both emergency and
non-emergency situations.
Ensure that adequate training is provided to all
employees concerning emergency and notification
procedures in the event of an accident.
* Ensure that the proper protective equipment is
easily accessible in case hydrogen fluoride is
released. Train employees in the proper use of the
equipment. Inspect and test the equipment
regularly.
* Have trained medical and/or emergency response
personnel and adequate supplies (including first
aid supplies) on site, or quickly available, to
provide proper first aid in case of exposure.
Hazard Awareness:
Avoid unintended contact between hydrogen
fluoride and other chemicals. Hydrogen fluoride
may react with other substances (e.g., alkalies,
some oxides, sulfides, and cyanides), sometimes
violently, and sometimes producing toxic gases.
Risk Minimization:
Use good design and engineering practices for
locating equipment containing hydrogen fluoride
to minimize damage from possible equipment
ruptures, explosions, or fires.
Control access to hydrogen fluoride areas to avoid
entry by untrained personnel.
Ensure that no containers are leaking or broken,
and conduct regular maintenance checks of all
equipment and containers coming in contact with
hydrogen fluoride, particularly checking for
evidence of corrosion.
Design hydrogen fluoride facilities with systems to
minimize releases in the event of a leak or
malfunction (e.g., by providing valves to isolate the
area of the leak or providing the means to rapidly
transfer the hydrogen fluoride to a different
vessel).
Have procedures in place for quick, organized
response in case of a release of hydrogen fluoride.
Emergency Notification:
In the event of a release, contact the National
Response Center [(800) 424-8802], your SERC and
LEPC, the local fire department, police
department, and other local emergency responders.
When contacting these organizations, provide the
following information: chemical name, estimate of
quantity released, time and duration of the release,
affected media (e.g., air, surface water,
groundwater), potential health risks, and the name
and telephone number of a contact person at the
facility.
CLEAN AIR ACT AMENDMENTS
Hydrogen fluoride is specifically mentioned in the accidental release provisions of the Clean Air Act
Amendments of 1990. This law requires EPA to promulgate an initial list of at least 100 substances that may
cause death, injury, or serious adverse effects to human health or the environment. Congress has identified the
first 15 substances to be included on this list; hydrogen fluoride is among them. Where regulated substances
above the threshold quantity are present at a facility, the owner/operator will be required to prepare a risk
management plan that includes a hazard assessment, an accidental release prevention program, and a response
program. The law requires that EPA publish regulations under the amended Clean Air Act within three years,
and allows facilities an additional three years to comply. Facilities will be required to provide copies of the risk
management plan to the LEPC, as well as to the state. Under the Clean Air Act Amendments of 1990, EPA
also was directed by Congress to carry out a study of the potential hazards of hydrogen fluoride to the public
and to make recommendations for the reduction of such hazards.
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OTHER INFORMATION
The following is a list of some sources of information about hydrogen fluoride and the Emergency Planning and
Community Right-to-Know Act.
The American Petroleum Institute (API)
Recommended Practice 751, "Safe Operation of
Hydrofluoric Acid Alkylation Units." Call API at
(202) 682-8375.
API background paper, "The Use of Hydrofluoric
Acid in the Petroleum Refining Alkylation Process."
Call API at (202) 682-8163.
CHEMTREC, a 24-hour emergency hotline that
provides information and assistance to responders
during an emergency. Contact (800) 424-9300 or
(202) 483-7616. (Note: CHEMTREC is for
emergency use only.} A call to CHEMTREC will
also activate the Chemical Manufacturers
Association's HF Mutual Aid Group, comprised of
specially trained teams that respond to emergencies
involving hydrogen fluoride.
Response Information Data Sheets (RIDS) that
include hydrogen fluoride response information are
found in CAMEO, a computer-based planning
and response management program that is available
from:
The National Safety Council
444 N. Michigan Avenue
Chicago, IL 60611
(312) 527-4800 (x6900)
Your County or State Health Agency.
Your State Emergency Response Commission.
Your EPA Regional CEPP Coordinator. EPA
Regional offices are located in Boston, New York,
Philadelphia, Atlanta, Chicago, Dallas, Kansas City,
Denver, San Francisco, and Seattle.
EPA's Emergency Planning and Community Right-
to-Know Information Hotline at (800) 535-0202, or
(703) 920-9877 from Monday to Friday, 8:30 a.m. to
7:30 p.m., Eastern time.
Chemical Manufacturers Association, Hydrogen
Fluoride Panel. For further information, contact
Fernando Leiva (202) 887-1100.
"Hydrofluoric Acid Anhydrous - Technical:
Properties, Uses, Storage and Handling," DuPont
Chemicals and Pigments. Contact (800) 441-9442.
"Recommended Medical Treatment for
Hydrofluoric Acid Exposure," Allied-Signal, 1991.
Contact Allied-Signal Technical Services, (800) 622-
5002.
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This advisory is the third of a new series which EPA is publishing to alert LEPCs to hazards posed by
hazardous substances that have resulted in accidents where death, injury, or evacuations have occurred. LEPCs
arc responsible for emergency planning for hazardous materials and for collecting and managing data on
hazardous chemicals present in their community.
Please send comments on this Advisory and suggestions for future topics to:
CEPP Advisory
EPA OS-120
401 M Street, SW
Washington, DC 20460
Additional copies of this advisory and the earlier advisories on swimming pool chemicals and ammonia are
available from the above address or by calling (800) 535-0202 or (703) 920-9877.
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