Which class of materials would be indicated by a yellow DOT placard?

The correct indication of a yellow DOT placard is associated with oxidizers. These materials are capable of providing oxygen to support the combustion of other materials, which can significantly increase fire risks when they are involved in an incident. The yellow color serves as a visual alert to responders and workers about the potential hazards posed by these materials.

In the context of hazardous materials placarding, each color and symbol is carefully chosen to convey specific dangers quickly. While explosive materials, flammable solids, and corrosive substances each have their unique classifications and color-coded labels, they do not share the yellow designation that specifically identifies oxidizers. Understanding this classification helps ensure proper handling and emergency response protocols are followed, minimizing risks in situations involving hazardous materials.