Which term describes the process of making a situation less harsh or severe?

The process of making a situation less harsh or severe is accurately described by the term "mitigate." In the context of hazardous materials, mitigation involves taking steps to reduce the impact or severity of a hazardous situation, such as a chemical spill or other emergency incidents. This might include implementing safety measures, using containment methods, or applying chemicals that neutralize the hazardous substances.

By focusing on prevention and damage control, mitigation is crucial in emergency response strategies to protect individuals, property, and the environment from the consequences of hazardous materials incidents. Other terms listed do not capture this essence of reducing severity or harm. For example, oxidation refers specifically to a chemical reaction where a substance loses electrons, while polymerization involves the process of combining smaller molecules into a larger compound. "Hazard" describes a potential source of harm rather than a process for alleviating harsh conditions. Thus, "mitigate" stands out as the term that directly connects to the concept of reducing severity in adverse situations.