What does UN Hazard Class 9 encompass?

UN Hazard Class 9 is designated for "Miscellaneous Substances." This classification encompasses a variety of materials that do not fit neatly into the other defined hazard classes but still pose certain risks during transport. These substances can include items like environmentally hazardous substances, certain marine pollutants, and materials that may present a hazard but do not fall under more specific classifications such as flammable, corrosive, or toxic.

While the other options refer to specific hazard classes—flammable solids, oxidizers, and toxic materials—these substances have clearly defined characteristics and are categorized separately due to their distinct risks. Miscellaneous substances can include a wide range of materials, reflecting their diversity and the need for careful handling and transportation even though they are not classified as high-risk items under the other hazard categories. This classification is critical for ensuring that all potentially hazardous materials are properly managed in transportation to maintain safety standards.