Environmental Health & Safety

Laboratory Safety Sub Committee

HARVARD UNIVERSITY SAFETY ALERT

HYDROFLUORIC ACID

(ACGIH recommended ceiling=3ppm)

Some of our laboratories use hydrofluoric acid (hydrogen fluoride, fluoric acid, HF). An extremely corrosive and irritating acid and a possible mutagen, HF is highly toxic if swallowed, absorbed though the skin, or contacted by the eyes or mucous membranes. Concentrated HF burns covering 2% of the body can be fatal. An air concentration of 50-250 ppm. can be lethal, even for brief exposures. HF produces severe skin burns which are slow in healing and, if untreated, HF can quickly penetrate skin to attack underlying tissues and bone. Such burns, which can be caused by HF solutions less than 2%, may not cause pain and may not be visible until several hours have elapsed since contact. Subcutaneous tissues may be affected, becoming blanched and bloodless; gangrene of the affected areas may follow. When HF is heated, it emits highly corrosive fumes of fluorides; it will react with water or steam to produce toxic and corrosive fumes. Contact with glass, concrete and other silicon-bearing materials yield silicon tetrafluoride gas. Contact with common metals will produce hydrogen fluoride gas creating a fire and explosion hazard. Contact with several other substances can also cause hazardous conditions (See Material Safety Data Sheet available from the Safety Office or EH&S - see below)

Rubber gloves, goggles and lab coats should always be worn when working with HF or HF solutions and all work with HF should be done in a designated area in a fume hood. Store in a suitable secondary container. As with all laboratory chemicals, do not mouth pipet HF solutions and be sure that such solutions are clearly labeled.

Symptoms of exposure may include irritation to skin, eyes, nose and throat, redness, edema, and blistering of the skin. But it is important to note that contact with solutions in the 20%-50% range may produce no immediate symptoms. In case of suspected exposure by inhalation, remove to fresh air, then call UHS or the Harvard Police for immediate medical attention. For suspected eye exposure, immediately flush with water for at least 15 minutes with large amounts of water then transport to UHS. For suspected skin exposure, flush immediately for at least 5 min. with large amounts of water while removing contaminated clothing; follow wash with the application of calcium gluconate gel (available in the Biolabs and Chemistry stockrooms) and transport to UHS. In case of ingestion, give large amounts of water to drink as quickly as possible to dilute, followed by several glasses of milk or several ounces of milk of magnesia, MAALOX, MYLANTA, etc., then; meanwhile, call the Harvard Police for immediate medical attention. Further first aid information is available from the Safety Office. Be sure your lab has the appropriate antidotes listed above, that they are readily accessible and that everyone in your lab knows where they are.

As with all accidents, report any exposure as soon as possible to your Lab Supervisor and Lab Director.

Dispose of HF properly, depending on other chemicals or isotopes present.

If you have HF in your lab, please call the Safety Office to arrange for a workplace evaluation and additional information.

Phone Numbers
Office	Days	Nights,Weekends
POLICE	5-1212	5-1212
UNIV. HEALTH SERVICES	5-5711	5-5711
ENVIRONMENTAL HEALTH AND SAFETY	5-2852	5-5560
CMB SAFETY OFFICE	5-7767	5-5560
CMB DIRECTOR'S OFFICE	5-2302	5-5560