Microengineering lab Hydrofluoric Acid Protocols
Emergency response summary for skin exposure:
Detailed medical response is available in this
HF Medical Book
published by Honeywell
and at their HF acid web site.
- Start washing immediately in emergency shower,
- remove clothing while washing,
- continue to wash for at least 5 minutes,
- then immediately rub in caclium gluconate gel (if not available, continue to wash
until help arrives).
- Call 911 and report extent of hydrofluoric acid exposure
and first aid given.
Hydrofluoric acid (and dilutions of HF with water or ammonium fluoride)
are particularly dangerous,
and require special training before use; users must be authorized by
the lab manager. Hydrofluoric acid rapidly diffuses through the skin, but
has poor warning properties; if your skin is exposed, you may not
feel the burn for some time. By the time you do feel it, it may be
too late to prevent serious damage to tissue and bones. In addition,
death due to hypocalcaemia may result from skin
contact to HF mixes over as little as few percent of the body, even
with some rinsing of the exposed area [
Brittish Occupational Hygene Society, Vol. 40, No. 6, PP. 705-710, 1996
]. HF fumes are also very dangerous. Hydrofluoric acid looks like water.
- Refer to the HF MSDS sheet
- Use and mixing is to occur only in the fume hoods with adequate ventilation and a sash well down to protect the face from any splash.
- Double gloves (thin nitrile plus thick Trionic or other gloves
containing Neoprene), an acid apron, and safety glasses are required.
The thin nitrile gloves alone are not good protection against HF;
diffusion through them may be significant. Even thick nitrile
gloves such as nitri-solve 727 start to show permeation in an hour.
Test the Trionic gloves for integrity before use; if in doubt,
use a new pair.
- Always check to be sure the incoming air filter fan is set to minimum flow rate, and the exhust duct is well open, so as to ensure negative pressure in
- Use the minimum amount of HF necessary for the job; large jobs such as furnace tube etching are to be done only under direct supervision of the laboratory manager.
- Never store HF in glass or metal containers--it will etch them.
- Waste HF should be put in plastic and tagged for disposal by EHS.
- In case of suspected skin contact with HF, rinse for 15 minutes, apply Ca gluconate gel (tube above acid cabinet), and immediately seek medical