Laboratory Equipment

Oil baths should always be monitored via a thermometer or other device to ensure that their temperature does not exceed the flash point of the oil being used. Smoking, caused by the decomposition of the oil or of organic materials in the oil, represents another hazard. A laboratory worker using an oil bath heated above 100°C should be careful to guard against the possibility that water (or some other volatile substance) could fall into the hot bath. Such an accident can splatter hot oil over a wide area. The oil bath should not be supported on an iron ring because of the possibility of accidental tipping.

The ordinary household refrigerator is not equipped with explosion-safe controls or door switches and should not be used to cool flammable liquids because sparks from controls or door switches may ignite the vapor-air mixture. Explosion-safe refrigerators are constructed with its controls mounted outside the storage compartment. This type refrigerator is suitable for storing flammable liquids. An explosion-proof refrigerator also has its controls mounted on the outside, but in addition, the controls are of an explosion-proof design. This type is needed only where both the internal and external environment present a fire or explosion hazard. Every refrigerator should be clearly labeled to indicate whether or not it is suitable for storage of flammable liquids. Flammable liquids stored in a refrigerator must be in closed containers. Laboratory refrigerators should not be used for storage of food or beverage unless used solely for that purpose and labeled as such.

Where (Bunsen) burners are used, distribute the heat with a wire gauze pad. Burners should not be left on when not in use. Workers should understand the hazards of burners before proceeding with an experiment.

Hand protection should be utilized when inserting glass tubing into stoppers or when placing rubber tubing on glass hose connections. To insert glass tubing, fire-polish the ends of the glass tubing; wet the glass and stopper hole with glycerin or water; wrap a cloth around the glass; hold hands close together and rotate the glass back and forth. Never attempt to push the glass into the stopper or tubing. To remove glass tubing and/or thermometers from stoppers: Lubricate the tubing with water or glycerin; wrap the tubing with a towel; gently twist the tubing, pulling lightly; if the tubing is stuck to the stopper, gently insert the end of a rat-tailed file between the tubing and stopper, and rotate gently, while lubricating with glycerin. If this method fails, cut the stopper away.