What is the Guide Number to use if there is no identifying information and the material is believed to be hazardous?

The correct answer utilizes the Guide Number 111. In emergency response situations, particularly those involving hazardous materials, the Guide Numbers provide critical information for first responders to safely manage the risk. When there is no identifying information about a substance and there's a suspicion that the material is hazardous, the Guide Number aids in determining the appropriate safety measures and actions to take.

Guide Number 111 corresponds to a category of chemicals that are noted for their potential hazards. It typically highlights the need for special precautions when approaching unknown substances. Such guidance is crucial for maintaining responder safety and effectively containing the situation.

In the context of hazardous material, the selection of this specific Guide Number reinforces the importance of caution when dealing with unidentified materials, ensuring that responders are vigilant and prepared for a variety of dangers that may arise from them. The other Guide Numbers do not apply to situations lacking identification or that indicate an unknown hazardous material, making 111 the necessary choice in this scenario.