1. Safe Use and Operation of Vacuum Lines, UCLA Chemistry and Biochemistry2. http://www.monash.edu.au/ohs/topics/hazard-alerts/vacuum-pumps-cold-traps.html

VACUUM SAFETYJULY 26, 2011

STARTING UP• Ensure that the vacuum trap is dry and clean.

• Lower the trap into the empty Dewar.

• Ensure that all valves are closed, and start (or open line to) the vacuum pump.

• Fill the Dewar with liquid nitrogen and wrap the top with a towel.

• Make sure all vessels attached to the line are under nitrogen.

• Carefully lower the Dewar and turn the pump off.

• Vent the system to air and wait for any frozen liquid to thaw.

• Dispose of any solvent.

SHUTTING DOWN

• Notify all laboratory personnel.

• Wear a face shield, fastened lab coat and thick rubber gloves.

• Lower the Dewar and vent the system.

• Carefully place a safety shield around the trap. Do not attempt to remove.

• Leave cold trap to stand overnight vented to air and then carefully re-inspect to check that all suspect material has evaporated.

IF LIQUID O2 IS PRESENT

• NEVER let the trap sit in liquid nitrogen for more than a minute without having the vacuum pump turned on.

• Under NO circumstances should the system be left open to air with the Dewar containing liquid nitrogen in place.

FINAL WORDS