Lab Safety Guide - Chapter 7- Use of Lab Apparatus
The following gives information on the assembly and use of apparatus related to laboratory work. Adapted from the NMSU Lab Safety Guide (modified - dls)
Prior to equipment set-up, the appropriate
Hazard Review Checklist (Appendix X) must be completed
to determine if adequate safety plans were considered in your equipment design.
The completed checklist is reviewed by your supervisor or departmental Safety Personnel.
The apparatus should be set up in a clean and dry area. Be certain that the equipment is firmly clamped and is kept well back from the edge of the laboratory bench. Many accidents occur when someone walks by a bench and brushes against the glassware. Please insure that the proper size equipment is used allowing at least 20% free space. Flasks that contain solutions to be refluxed should have 50% free space. Position and clamp reaction apparatus thoughtfully in order to permit manipulation without the need to move apparatus until the entire reaction is completed. Combine reagents in appropriate order, and avoid adding solids to hot liquids.
NEVER use glassware that is chipped, cracked, etched or flawed in any way.
Keep workspace uncluttered. Only the required materials, instructions, notebook and pen should be present. Keep the work area free from extraneous chemicals, scraps of paper and paper towels. Keep all other glassware far back where it will not be knocked over.
Ground glass joints or stopcocks should be sleeved with Teflon or freshly lubricated unless a lubricant will contaminate the system. Retainer rings should be used on stopcock plugs.
Condensers must be properly supported with securely positioned clamps. Any attached water hoses must be clamped with stainless steel hose clamps only. Condensers running unattended overnight should be attached to a water pressure regulator in order that surges in the water pressure do not cause the hoses to rupture. Also, a catch pan or tray of sufficient volume (with a drain hose) must be positioned under the condenser unit.
Stirrer motors should be secured to retain proper
alignment. An air driven stirrer or magnetic stirrer should be used whenever possible.
Only non-sparking motors can be used in hazardous areas, around flammable gases and
solvents. If a sparking stirrer motor must be used, both the Experiment Safety Plan
(Appendix IV) and the Hazard Review Checklist (Appendix X) must address its use and a
procedure must be written to ensure sufficient ventilation and fail-safe emergency
To avoid injuries while cutting glass tubing, hold the tubing against a firm, notched support; make ONE quick firm stroke with a sharp file, rocking the file to extend the deep nick one-third around the circumference. Hold the tubing in both hands, away from the body, with the nick turned directly opposite the body. Place the thumbs on the tubing opposite the nick about an inch apart. With hand protection (gloves or towel), push out on the tubing with the thumbs.
ALL GLASS TUBING AND RODS MUST BE FIRE POLISHED OR FILED BEFORE USE.
The most common injury sustained in the laboratory occurs from the improper insertion of glass tubing into a rubber stopper. See Appendix XI for safe procedure to insert glass tubing or thermometers into rubber stoppers. The purchase of "safety stoppers" specifically designed to prevent injury during glass insertion are strongly recommended.
Vacuum pumps must always have a belt guard. If a belt guard is not available in the lab, see the departmental safety officer/supervisor.
If a cooling bath is required for use on a vacuum system (or any other system) and ice water is not cold enough, dry ice in an organic liquid should be used instead of liquid nitrogen whenever possible. The ideal cooling liquid for a dry ice bath should be relatively non-toxic, non-viscous, nonflammable, nonvolatile, insoluble in water and should float dry ice. Ethylene glycol thinned with two thirds water or isopropanol makes a fairly viscous cooling mixture. These baths have some disadvantages which should be considered. The solvents used can wet the skin, so spills can result in severe burns.
Hardware, regulators, glassware, solvents, dry chemicals, acids, etc., stored in the laboratory must be isolated from each other in separate cooling bath to prevent breakage and to avoid other undesirable interactions.
including varices, stirrers, vacuum pumps, etc., must not be powered by extension cords or
frayed line cords. Grounded plugs must be used without exception; existing ungrounded
plugs must be changed immediately.
Any equipment or experiment that is operated overnight
must have emergency information displayed on
the Experiment Hazards Form below.
Each experimental setup should have a Experiment Hazards Form completed and plainly posted for all to see. It is to Be Placed on Each Experiment in Progress)
Lab Safety Programs, Procedures, & Guides