What is the primary hazard associated with the materials classified under Group D chemical agents?

The primary hazard associated with materials classified under Group D chemical agents is the generation of highly toxic fumes. This classification typically includes chemical agents that can release harmful gases or vapors when released into the environment or during certain reactions. These fumes pose significant health risks to individuals who may be exposed, necessitating stringent safety measures to prevent inhalation or contact.

Understanding this hazard is crucial for handling and transporting these materials, as it emphasizes the need for proper ventilation, protective gear, and emergency response tactics to mitigate the risks of exposure to toxic fumes.