Guidelines For Handling Hydrofluoric Acid

Properties

Hydrofluoric Acid is an aqueous solution of Hydrogen Fluoride gas. Hydrogen Fluoride gas is liquefied under pressure and is hygroscopic. Its boiling point is 20¡C.
Hydrofluoric Acid is a colorless liquid with a pungent odor.
Hydrofluoric Acid is highly toxic and corrosive, even in concentrations as low as 1 to 7 %.
Hydrofluoric Acid irritates the eyes, the skin and the mucous membranes in mouth and throat.
Hydrofluoric Acid solutions deeply penetrate before dissociating, thus causing delayed injury and symptoms. The devastating effects can persist over long periods of time.
Evaporation at room temperature can raise the concentration in the room readily to dangerous levels.
Exposure to a concentration of 8000 ppm can be fatal.

Hydrofluoric Acid is a strong acid and reacts vigorously with many metals forming flammable gases.
Hydrofluoric Acid releases corrosive vapors when exposed to the air. As these vapors are heavier than air, they spread freely over the floor.
Hydrofluoric Acid dissolves glass and silicates.
Hydrofluoric Acid corrodes polymers.

Substitute a less hazardous alternative, if at all possible.
Prior to any experiment involving the use of Hydrofluoric Acid, prepare a risk assessment and submit this to the HSE Department along the guidelines outlined in the Procedure for activities with chemical products.
Hydrofluoric Acid must be handled only in a closed hood.
Always wear personal safety devices: lab coat, goggles or face shield, rubber gloves (preferably butyl rubber, if not available neoprene of PE gloves). Wear only long gloves that protect hands, wrists and underarms.
Wherever Hydrofluoric Acid is used, appropriate and clearly visible marking detailing the hazards involved shall be put in place.

Hydrofluoric Acid must be stored in a well-ventilated cabinet, separate from incompatible chemicals like bases, metals and organic compounds.
Never use glass recipients as they will dissolve gradually.
Mark the recipient with a label indicating the location of the anti-dote Calcium Gluconate (see First Aid).

Use Sodium Bicarbonate to neutralize the spill. Beware of potential splashing.
Use the absorbing materials from the Intervention kit to remove the spill.
Dispose of all contaminated material as Chemical Waste Class 6: Small Chemical Waste (KCA).
Always wear personal safety devices when cleaning up a spill. Some spills require additional safety devices to be used.

Protective clothing may be necessary to avoid direct skin contact. Special overalls with head protection are available from the Central Warehouse.
The use of a full facial gas mask with cartridge types E or B may be appropriate.

Immediately rinse skin with copious amounts of water to remove all adsorbed acid. Any penetrated Hydrofluoric Acid will not be removed by this water treatment. Therefore immediately apply plenty of 10% Calcium Gluconate ointment on the contact area. Leave the ointment layer in place for at least 15 minutes after the pain has disappeared. The Gluconate prevents the creation of deep burns.
Treat eyes with plenty of water.
After every first aid intervention, direct the victim to medical assistance in the emergency ward.
Calcium Gluconate ointment is available from the HSE Service. Calcium Gluconate ointment has a shelf life of approximately 12 months. Keep a close watch on the expiration date.

Last revision: August 24, 2010