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California State University, Long Beach
College of Natural Sciences and Mathematics

Safety Training for Hydrofluoric Acid Users


Hydrofluoric Acid (HF) is different from any other kind of acid. It is very aggressive physiologically (see below). You may not work alone with HF - the buddy system must be used!

Mandatory Safety Precautions

Before you begin working with HF, make sure of the folllowing:

  • Another person (buddy) is nearby.
  • You must work in the chemical fume hood.
  • Make certain the fume hood is working properly: indicator shows proper airflow, sash pulled down to or lower than the arrow, hood is not too full.
  • The emergency eyewash/shower is nearby and is operational (not posted "out of service").
  • Confirm that a new, unexpired tube of Calcium gluconate gel is at your workstation.
  • The "HF Emergency Info" envelope is located nearby and you know the location.
  • Make sure you have immediate access to a phone or emergency call box.
  • Recall that HF dissolves glass, so work only with plastic containers, pipettes etc.
  • Wear lab coat with acid apron, HF-compatible gloves (nitrile and latex OK) and chemical safety goggles. If face shield used, you must still wear goggles underneath.

Hazards of HF

HF skin or eye exposures are usually extremely serious, with significant complications possible due to fluorine toxicity. HF liquid or vapor is both highly corrosive and toxic due to the F ions which readily penetrate the skin and cause destruction of deep tissues and bone, a process which can continue for days if left untreated. Concentrated HF (liquid or vapor) may cause severe burns; lowering of serum calcium, magnesium, potassium etc. and other metabolic changes; pulmonary edema; life threatening cardiac arrythmias etc. Even moderate exposures to concentrated HF may lead quickly to death if left untreated; hypocalcemia is a possible risk in all instances of inhalation, ingestion, and whenever skin burns exceed an area of 5 inches by 5 inches.

Hazard According to Concentration- Note: a 48% aqueous solution is usually purchased.

  • Concentrations of 40% or higher produce hazardous vapors. Vapors have adequate warning properties.
  • Concentrations of less than 40% normally do not produce hazardous vapors unless heated.
  • Concentrations of more than 50% cause immediate severe burning, and throbbing pain on contact.
  • Concentrations from 20-50% may not produce clinical signs or symptoms (including pain) after skin contact for 1-8 hours.
  • Concentrations less than 20% may not produce clinical signs or symptoms after skin contact for up to 24 hours.
  • Concentrations as low as 2% may cause injury if the skin contact time is long enough.

First Aid and Medical Treatment

HF burns require immediate and specialized first aid and medical treatment. Treatment focuses on binding the Fluorine ion to prevent tissue destruction. SPEED IS OF THE ESSENCE. Relief of the throbbing pain of HF burns is an excellent indicator of treatment progress; local anesthetics should be avoided. Medical help must be obtained as the information below is only a general guide to be used until medical help arrives. 2.5% Calcium Gluconate gel is the preferred treatment for HF burns. Keep it close to your work area and know where it is!

1. Skin Contact

  • Flush with large amounts of cool water for 5 minutes (NOT FIFTEEN) while sending someone to call 911; remove all contaminated clothing
  • Apply 2.5% calcium gluconate gel to the affected area. Massage gel into the burn site, reapplying every 15 minutes. This may be repeated over hours or even days.
  • The success of the treatments for severe burns is indicated by pain relief. If pain recurs upon stopping treatment, the treatment must be continued. Serious burns usually also require calcium gluconate injections.

2. Eye Contact

  • Flush the eyes for at least 15 minutes with large amounts of water. A sterile 1% calcium gluconate solution may be used if available after five minutes of flushing with water.

3. Inhalation

  • Medical personnel should administer a nebulized solution of 2.5% calcium gluconate.

4. Ingestion

  • Have the victim drink large amounts of water as quickly as possible. Do not induce vomiting. If available, give several glasses of milk or several ounces of "Maalox", "Mylanta", or administer a few "Tums" antacid tablets.

HF Hazardous Waste Collection

Collect your HF liquid waste in a plastic container since HF dissolves glass. Collect solid waste (e.g. pipettes etc.) in a plastic bag. Make sure you put the yellow, pre-printed CSULB Hazardous Waste Sticker on the waste bottle or bag. Fill out the label immediately, and call CNSM Safety x55623 for disposal when needed. Do not let the waste get older than 6 months.