Ben Hirst Hazardous Materials Awareness and Operations Practice Exam 2026 – Comprehensive All-in-One Study Guide for Success!

Placing a hazard class number on a placard is how carriers show the broad type of danger inside the package. The number six signals Class 6 hazards, which covers toxic substances as well as infectious substances. Among the options, only infectious substances fall under this class, since they are materials contaminated with pathogens that can cause disease and require careful handling and labeling. The other options belong to different hazard classes: oxidizers are a different class, corrosives another, and explosives yet another. So a Class 6 placard points to infectious substances in this context.