What defines an oxidizer in hazardous materials?

An oxidizer in hazardous materials is defined as a material that readily yields oxygen, which plays a crucial role in igniting or maintaining combustion. These substances can enhance the fire risk by providing the oxygen needed for a fire to burn, and thus they are often a significant concern in emergency response scenarios.

In the context of hazardous materials, understanding the properties of oxidizers is vital for handling, storage, and transportation to prevent potential fire hazards. Oxidizers can include common materials such as hydrogen peroxide, potassium nitrate, and chlorine, all of which can support and accelerate the combustion of other materials by releasing oxygen.

The other options describe different characteristics that do not apply to the definition of an oxidizer. For example, retaining heat would refer to thermal properties rather than chemical reactivity, neutralizing acids pertains to buffering agents, and a non-flammable liquid simply characterizes a substance's flammability without indicating its relation to oxygen or combustion. Thus, the proper identification of an oxidizer as something that readily yields oxygen is crucial for effective safety and emergency procedures.