Use of the Sodium Press to make Sodium Wire for solvent drying

This Risk Assessment should be read in conjunction with that for “Transport, Storage and Use of Solvents and other Flammable Liquids“.

Known or expected hazards

• Severe fire from sodium and ignition of solvent.
• Fire caused by incorrect disposal of unused sodium.
• Violent reaction between sodium and unsuitable solvent.
• Pressure build up in solvent bottle following addition of sodium.

Precautions

• This operation must never be attempted by an untrained person.
• This operation must never be attempted by a single person.
• This operation must never be attempted out of normal working hours.
• Lab-coats, gloves and safety glasses must be worn.
• No naked flames to be within twenty feet.
• No other flammable chemicals to be within ten feet.
• If the press is found with residue from a previous operation, it must be assumed that sodium is still present and extreme care must be taken in cleaning it.
• Only solvents compatible with sodium to be used (see the recommended solvent drying agents given in the Risk Assessment “Distillation of Solvents”).
• The solvent bottle to be held firmly in place with the mouth as close as possible to the die.
• Following the operation, the solvent bottle must be left in a fume cupboard for 18h. with its cap screwed loosely in place.
• Unused sodium to be disposed of carefully (see the procedure outlined in the Risk Assessment “Distillation of Solvents”).
• In order that the press be safe for future use, it must be left spotlessly clean.
  Glass bottles which contain sodium and solvent should be handled with extreme care. An incident has occurred in the School of Chemistry when such a bottle, which was being carried, struck and smashed on the edge of a bench. The person involved slipped on the spilled solvent and fell into the pool on the floor absorbing the solvent into their clothing. It was only the speed of a co-worker in dealing with the exposed sodium wire that prevented an horrific burning accident.

Risk Remaining

Provided the above procedures are adhered to, the risk of injury is low. However, any fire that does occur is likely to be serious especially when highly flammable solvents are being used. It is therefore important that persons undertaking this operation are familiar with the correct procedure for dealing with solvent fires.

Back to Completed Risk Assessment Forms

Adapted with permission from School of Chemistry, University of Bristol