Which hazard class includes materials such as oxidizers and poisons?

The correct answer is Hazard Class 5. Within the context of hazardous materials, Hazard Class 5 specifically includes oxidizers and organic peroxides. Oxidizers are materials that can cause or enhance the combustion of other materials due to their reactive nature, and this classification plays a critical role in emergency response protocols and safety measures.

Meanwhile, the other options represent different categories of hazardous materials. Hazard Class 3 pertains to flammable liquids, which can pose fire hazards. Hazard Class 2 includes gases, which are under pressure and can also present various risks. Hazard Class 6 encompasses toxic materials and infectious substances, but it is distinct from Hazard Class 5, which focuses specifically on oxidizers and their unique hazard profiles.

Understanding these classifications is essential for effective emergency response planning, as it informs responders of the nature of the materials involved and the necessary precautions to take when managing incidents involving hazardous substances.