Strong solutions of the acid cause a quick onset of burning, redness and tissue damage. Symptoms may be delayed up to 24 hours after exposure to a less concentrated HF solution. People using HF products while wearing leaking gloves can develop symptoms many hours later or even the next day. They have red, painful fingers with severe burning under the fingernails. The pain from the burn may be intense and treatment is difficult.
Major exposures require treatment in an emergency room.
Before you have a problem, check your supply of cleaning products for any rust removers, water spot stain removers, tar removers or mag wheel cleaners. Read these product labels carefully to see if they contain either hydrofluoric acid or ammonium bifluoride. Ammonium bifluoride is converted to hydrofluoric acid and can cause the same kind of problems. Unfortunately, many labels are not clear and it may be difficult to determine the ingredients. If you are not sure, be safe and assume the worst.