According to the 49 CFR Section 172.604(a)(1), what must the emergency response telephone number be?

The emergency response telephone number must be monitored at all times the hazardous material is in transportation. This requirement ensures that, in the event of an accident or a hazardous materials incident, trained personnel can immediately access information about the material involved, including safety measures and response actions necessary to handle the situation. The availability of this number during transportation is critical for protecting public safety and minimizing risks associated with HAZMAT incidents.

While it’s important for the number to be accessible during storage and to be listed on labels, the regulation specifically emphasizes that monitoring during transportation is essential because this is when the material is most likely to pose a risk. This proactive measure helps ensure that emergency responders and other involved parties can quickly obtain guidance on how to safely manage the hazardous materials they are dealing with.