Many chemicals found in the laboratory are unstable and incompatible with water.
The hazards involved when water comes in contact with a water reactive material arises from one or more of the reactions shown in the following table. The above reactions create a particularly hazardous situation for firefighters, since water is most commonly used for fighting fires. Water used to put out a fire involving water reactive materials will only serve to intensify the fire situation. This label should also serve as a warning to all laboratory personnel to store and use these materials in areas where the use of water is restricted. Water reactive chemicals should be stored in an isolated area within the lab, preferably in a water-tight cabinet well away from water use areas.