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University of Cambridge >  Nanoscience Laboratory Intranet > Safety Information > Chemical Handling > Use of Hydrofluoric Acid
 

Use of Hydrofluoric Acid
Local Rules - Nanoscience Bay 2

General

No one may work alone when using HF, you must always have another person listed on the intranet site as an HF user standing by while you work.

HF may only be used 9am to 5pm Monday to Friday.

You must be listed on the intranet site as an HF user

HF must not be removed from the designated area in Bay 2

HF solutions should be stored in the cupboard provided. If you wish to make up your own solutions you must consult one of the managers for advice. 7% solutions and Niobium Etch are provided and will be replaced when they run out. The solutions in storage will be regularly reviewed and those which are not needed will be disposed of.

You must consult one of the managers BEFORE purchasing any product containing HF. Solutions greater in concentration than 40% are not to be purchased for or used in nanoscience.

Before Starting Work:

You must ensure that a risk assessment is complete for your proposed activity, that your personal COSHH assessment has been updated and that you have a written step by step procedure for your process.

The key to the cupboard may be obtained from the lab manager, or one of the people listed as managers of the HF facility on the intranet site

Make sure you know what to do in an emergency, do you know where the phone is, the Cavendish first aid number and where the emergency shower is? Check that the antidote gel is in date!

Check that there is sodium hydrogen carbonate available for dealing with spillages.

Check that the fume cupboard is working.

While working:

Always use the smallest amount of HF possible for your application.

Always wear apron, face shield, arm protector and double gloves.

You should either use the thick black gloves provided or, for <10% solution, you may use the green gloves. These must be dated when first used and not used beyond one month. CHECK GLOVES FOR PINHOLES!

Do not use glass equipment, a supply of suitable polythene containers is provided.

Leave the outer gloves and arm protectors in the fume cupboard. As you will not have spilt any HF there should be no need to wash down. It should be assumed that any liquid pools or drops constitute an HF spill (see below).

Waste HF solution may be washed, once heavily diluted, to waste with copious amounts of water. Solutions containing other chemicals may need disposal, contact the lab manager for advice.

Emergencies:

Any exposure to HF must receive immediate first aid. Serious effects can be delayed, especially with weaker concentrations.

Small spillages in the fume cupboard:

Drops of <10% solution may be mopped up with a clean room wipe and the wipe left to dry in the fume cupboard.

Small spills of <100ml of <10% should be neutralised with the Sodium Hydrogen Carbonate, left for 10 minutes and then washed down to waste with lots of water.

Large spillages, spillages of >10% solution and spillages outside the fume cupboard:

Leave the bay, make sure everyone else does as well, leave your buddy in the corridor to prevent entry and seek assistance from the lab manager.

last updated 27-04-2006