What type of chemicals can emit flammable gases upon contact with water?

The correct answer highlights that certain chemicals specifically react with water to produce flammable gases, which can pose significant safety hazards. This category includes substances such as alkali metals (e.g., sodium, potassium) and some metal hydrides, which can produce hydrogen gas when they come into contact with moisture or water. The generation of flammable gases in the presence of water is particularly dangerous, as it can lead to fires or explosions if the gases ignite.

Understanding this type of chemical behavior is crucial for safety in environments where water and reactive chemicals are present. Proper storage and handling protocols must be in place to prevent unintended reactions. By recognizing the risks associated with chemicals that react with water, workers and safety professionals can implement effective measures to mitigate these dangers and promote a safer workplace.