Final answer:
If significant new information becomes available which changes the product hazard classification or safe handling procedures, the correct action to take is to distribute updated information.
Step-by-step explanation:
If significant new information becomes available which changes the product hazard classification or safe handling procedures, the correct action to take is D. Distribute Updated Information. It is important to distribute the updated information to ensure that everyone involved has the most current and accurate knowledge about the product hazards and safe handling procedures. This helps in minimizing any potential risks or accidents that may arise due to outdated information. Thus, updating and distributing the relevant information is crucial in maintaining safety and complying with regulations.