Which class of hazardous materials includes gases?

Class 2 is indeed the correct classification for hazardous materials that include gases. This class encompasses various types of gases that can be either flammable, non-flammable, or toxic, highlighting the diverse nature of gases as hazardous materials.

In the context of hazardous materials, the classification system serves to categorize materials based on their physical and chemical properties, facilitating safety protocols and emergency response strategies. Class 2 gases can be under pressure, which poses unique risks, such as explosive potential or asphyxiation hazards.

The other classes refer to different types of hazardous materials: Class 1 covers explosives, Class 3 includes flammable liquids, and Class 4 pertains to flammable solids, spontaneously combustible materials, and dangerous when wet materials. Each class has distinct characteristics, which is crucial for handling and transportation safety.