standard operating procedure for work with chemical name/class: hydrofluoric acid/hydrogen fluoride cas #: various pi:
Standard Operating Procedure
for work with
Hydrofluoric acid/hydrogen fluoride
Designated Work Area:
Back Left Fume Hood
This SOP has been approved by the following Principal Investigator:
Circumstances of Use:
Consider alternate methods and use a less dangerous acid if possible.
Liquid HF is one of the strongest and most corrosive acids. It can
be irritating to the skin, eyes, and respiratory tract. Contact
with exposed body parts can cause painful burns and even death.
In high concentrations (more than 50%), HF usually causes
immediate burns that are extremely painful and slow to heal.
In lower concentrations, exposure may not be apparent for several
hours, but can still cause burns and further damage if not washed
HF causes such severe burns because it penetrates beneath the skin
and dissociates into hydrogen and fluoride ions. When fluoride
ions bind with calcium in the body, it can result in tissue
destruction, decalcification of bone, cardiac arrhythmia, and
liver and kidney damage.
The OSHA Permissible Exposure Limit for hydrogen fluoride is 3
ppm. The American Conference of Governmental Industrial Hygienists
recommends a ceiling (instantaneous) limit of 2 ppm and an 8-hour
limit of 0.5 ppm.
Calcium gluconate gel will bind to the fluoride ions and prevent
further tissue destruction, but it must be applied quickly (even
if burns have not been felt) to be effective. Calcium gluconate
gel information is found at:
Consult the Safety Data Sheet (SDS) for your specific product and
the Laboratory Chemical Safety Summary for HF in Prudent Practices
in the Laboratory (National Academies Press). This information can
be found at:
Any work with HF must be done in a chemical fume hood.
An eyewash/drench hose combination unit must be available in the
immediate work area for any work with corrosive materials.
For many uses of HF, a safety shower will also be necessary.
Work Practice Controls:
Consider alternate methods and use a less dangerous acid if
Purchase HF in the smallest amounts possible.
Stock calcium gluconate gel and calcium carbonate antacid tablets
(Tums) to be used as first aid in case of an HF burn. (Medical
attention should still be sought immediately for HF burns.) Prior
to using HF, make sure the calcium gluconate tube is unopened and
that neither the gel nor the tablets have reached their expiration
Do not heat hydrofluoric acid.
Do not use glass, ceramic, or other incompatible containers for
Perform a dry run to identify and correct potential hazards.
Add acid to water, not water to acid.
Work within sight and/or hearing of at least one other person who
is familiar with the hazards and written procedures.
Set up a designated area for HF use and post a warning sign during
use. Post a sign at the door to the room when HF is in use.
Line work surfaces with plastic-backed absorbent paper and/or a
containment tray of compatible material.
Once work with HF is complete, decontaminate the area by wiping it
down with a 10% sodium carbonate (Na2CO3, also known as soda ash)
Gas hydrogen fluoride:
Follow SOP for compressed gas guidelines.
If you have any HF in lecture bottles, be aware that it can be
Personal protective equipment (PPE):
Wear a fully buttoned lab coat with sleeves extended to wrists, face
shield AND safety goggles, neoprene outer gloves and nitrile inner
gloves, long pants (or other clothing covering the entire leg), rubber
apron, and closed toed shoes. For small amounts of HF (<50 ml), double
nitrile gloves can be used but must be changed immediately if splashed
or thought to be contaminated.
Transportation and Storage:
Transport corrosives in secondary containment, preferably a
polyethylene or other non-reactive acid/solvent bottle carrier.
Liquid hydrofluoric acid:
Store in a compatible container (preferably polyethylene). HF
reacts with glass, ceramics, and some metals.
Place it in a compatible secondary container to capture leaks or
Store with other inorganic acids, away from bases and other
incompatibles including metal (unless the metal has a
corrosion-proof coating), and do not store under the sink.
Avoid storing on the floor.
Liquid or gas:
Store in well-ventilated areas.
Store below eye level.
Store away from incompatibles.
Dispose as chemical waste.
Immediate first aid and medical treatment following these guidelines
is essential for people exposed to hydrofluoric acid. People working
in areas where hydrofluoric acid is used should be familiar with these
guidelines and they should be readily available (printed out) and kept
with first aid supplies. A summary of first aid steps is included
below but, when possible, refer to the guidelines at the link.
For an actual chemical exposure/injury
Seek immediate medical attention at the emergency department for
any HF exposure.
Persons helping an exposed colleague must wear PPE as indicated
Call CUFD at 911 or 656-2222 from a campus phone.
For skin exposure:
If using calcium gluconate gel, flush with water for 5 minutes
then apply the gel by rubbing onto the burn site. Continue to
massage the calcium gluconate gel into the burn site during
transportation to a medical facility and while waiting to see a
physician. The person applying the calcium gluconate gel should
wear gloves to prevent a secondary HF burn. Use surgical gloves if
available or neoprene over nitrile.
If not using calcium gluconate gel, continue rinsing with water
until medical treatment can be provided.
For eye exposure:
Flush eyes for at least 15 minutes with large amounts of gently
If sterile calcium gluconate solution (1%) is available, flushing
eyes may be limited to 5 minutes, after which the calcium
gluconate solution (1%) should be used repeatedly to irrigate the
eye using a syringe.
Take the victim to a doctor, preferably an eye specialist, as soon
as possible. Use ice water compresses on the eyes during
For ingestion, administer a calcium-containing medication (such as
Tums) if available. Magnesium-containing stomach medication or
several glasses of milk may also be given. Get immediate medical
Notify your supervisor and, within 24 hours, fill out the report of
work-related accident, injury, or illness
Spills of HF in the fume hood (<5 ml) can be absorbed using magnesium
sulfate, soda lime, sodium carbonate (Na2CO3), or other spill
absorbent specified for HF. Do NOT use organic spill kits that contain
Floor-Dri, kitty litter, or sand because HF reacts with silica to
produce silicon tetrafluoride (a toxic gas). After spill has been
completely absorbed, wipe down spill site with 10% sodium carbonate
Training of personnel:
Training on the lab-specific procedures must be performed by the PI or
knowledgeable designee for all personnel working with HF and must be
documented (including date, employee names, signatures, and topics
covered such as location of calcium gluconate gel in the lab).
“I have read and understand this SOP. I agree to fully adhere to its
requirements. By signing below, I also acknowledge that I have
received lab-specific training for use of this chemical.”
Revised 6/4/2015: Removed hidden hyperlinks. Shortened sections 7 and
10. Added first aid information in section 8. Added “hands-on
training” information after signature page.