Final answer:
The statement is false; NFPA 704 signage, involving a hazard identification system with a colored diamond symbol, is developed by the NFPA, not by the DOT. The DOT regulates hazardous materials during shipping with a different classification system.
Step-by-step explanation:
The statement that NFPA signage is developed by the DOT and details hazard classes for materials that are shipped is false. The NFPA 704 Hazard Identification System is actually developed by the National Fire Protection Agency (NFPA), not the Department of Transportation (DOT).
This system provides essential safety information about substances, classifying them according to flammability, reactivity, and health hazards, using a distinctive diamond-shaped symbol with colored sections. The top red diamond indicates the level of fire hazard, the left blue diamond denotes the level of health hazard, the right yellow diamond represents reactivity hazards, and the bottom white diamond points out special hazards.
Materials that are shipped, however, are regulated under the United States Department of Transportation hazardous materials regulations, which have their own classification system. Hence, while the NFPA system is crucial for informing about hazards, it is not developed by the DOT, but by the NFPA itself.