HYDROFLUORIC ACID -
SPECIAL INSTRUCTIONS FOR CLEAN-UP
Hydrofluoric acid (HF)
can cause extreme irritation to the nose, throat and respiratory system at low
level vapor exposure. Severe exposures to vapors or contact with HF solutions
can cause nose and throat burns, lung inflammation and pulmonary edema. HF will
also deplete calcium levels in the body if not properly treated, resulting in
death due to hypocalcemia.
Due to the extreme toxicity
and corrosivity of HF any spill of this material must be cleaned up with great
All spills of Hydrofluoric
acid will be will be cleaned by the emergency response team. The immediate area
of the HF spill must be cleared of all non- response personnel. Depending on
the concentration of the HF solution and location of the spill, an EVACUATION
must be considered.
Minimum PPE for Hydrofluoric
acid response includes:
FULL NEOPRENE BOOTS WITH OVERBOOTS
KAPPLER CPF 2 (or higher) SUITS, with hoods up
NEOPRENE GLOVES with SOLVEX(TM) GLOVES AND N-DEX(TM)UNDERLINERS
HARD HAT WITH FACE SHIELD
Spill response information
and special precautions for Hydrofluoric acid:
1) Concentrated HF (70%)
solutions may be diluted with water before clean up to reduce hazards. However,
the water must be added slowly and carefully to prevent boiling of HF solution
due to exothermic reaction of water and HF. Contain spill before adding water
to prevent spread of contamination.
2) HF will react with
all silicon containing materials such as glass, concrete AND CHEMICAL SPILL
SORBENTS SUCH AS VERMICULITE AND MAGICSORB(tm). This reaction
will cause the generation of the highly toxic gas, silicon tetrafluoride. Spill
responders must be aware and prepared for this possibility.
(A) Using Liquid Neutralizer
The Hydrofluoric acid
will be absorbed on polypropylene pads, which will be placed in an appropriate
container (5 gal plastic pals or lined drums), secured and then transported
to the waste water treatment facility or the hazardous waste yard for treatment
The remaining acid residue
will be neutralized using a liquid acid neutralizer. The neutralized residue
will be absorbed on pads and placed in appropriate containers. This material
will be treated as a hazardous waste until determined otherwise.
This neutralization treatment
will be done at least three times, after which the contaminated site will be
analyzed using pH paper. Additional treatment will continue until all acid residue
Final clean-up will be
performed using normal and appropriate maintenance procedures for the contaminated
(B) Using Solid Sodium
Free liquid will be diked
and contained with the solid neutralizer. Sufficient material will be spread
over the spill to just cover the surface with a light coating. The solid will
be thoroughly mixed to effect absorption of all free liquid. If necessary, a
small quantity of water may be added to cool the slurry or increase the rate
of neutralization. If a color indicator is not present to monitor the pH, then
pH paper should be used. The responders should attempt to maintain the final
pH in the range of 6 to 10.
After all free liquid is absorbed and the residue is containerized, the area should be rinsed at least twice with water to remove residual contamination and excess solid neutralizer.