Accidents involving glassware are a leading cause of laboratory injuries. These can be avoided by following a few simple procedures. In general, be certain that you have received proper instructions before you use glass equipment designed for specialized tasks that involve unusual risks or potential injury. Borosilicate glassware is recommended for all lab uses except for unusual applications that may require glass with specialized characteristics (e.g. UV light work or demanding heat stress).
Glassware Use and Maintenance
- Handle and store glassware carefully so as not to damage it or yourself.
- Inspect glassware for chips, cracks or rough edges before each use.
- Properly discard or repair damaged items.
When inserting glass tubing into rubber stoppers, corks or when placing rubber tubing on glass hose connections:
- Protect hands with a heavy glove or towel.
- Lubricate tubing or stopper with water, stopcock grease or glycerol.
- Be sure that the ends of the glass tubing are fire-polished.
- Hold hands close together to limit movement of glass should fracture occur.
- Substitute plastic or metal connections for glass ones whenever possible to decrease the risk of injury.
- Use glassware designed for vacuum work for that purpose.
When dealing with broken glass:
- Wear hand protection when picking up the pieces.
- Use a broom to sweep small pieces into a dustpan.
- Package broken glass pieces in a rigid container (i.e. corrugated cardboard box) and seal to protect yourself and housekeeping personnel from injury.
- Never attempt glassblowing operations without proper facilities and training.
- Simple processes such as bending a tube or drawing out a tube to decrease interior diameter may be safely accomplished in the lab.
- Remember that glass remains hot after the red glow has faded.
- Score glass tubing about 1/3 the way around using a single stroke.
- Wrap the tubing in a cloth to protect hands.
- Place thumbs either side of the score mark opposite the score.
- Exert firm but even pressure on the tube.
Vacuum System Glassware
- Glassware used for vacuum distillations or other uses at reduced pressure must be properly chosen for ability to withstand the external pressure for the created atmosphere.
- Only round-bottom vessels may be subjected to vacuum unless specially designed, such as Erienmeyer-type filtration flasks.
- Each vessel must be carefully inspected for defects such as scratches or cracks.
- Wrap pressure vessels with several layers of friction tape or duct tape to reduce the number of glass fragments encase of breakage.
- Repaired glassware should be examined under polarized light to identify flaws or strains prior to use.
- Corks, rubber stoppers, rubber or plastic tubing should never be relied upon as a pressure relief device. Use a positive pressure relief device such as a liquid seal.
- Use metal fittings where glass pipe must be used.