Which item must be included on a pipeline warning sign?

The inclusion of an emergency contact number on a pipeline warning sign is vital for ensuring safety and response efficiency in the event of a leak or spill. This number provides immediate access to essential assistance, allowing responders and the general public to report incidents, obtain instructions, or receive further information about the hazardous materials involved.

While it might be important to have hazardous material identifiers, first aid instructions, and emergency response checklists available, these options may not be as critical for immediate contact and situational awareness as the emergency contact number. The primary function of a warning sign is to alert individuals to potential danger and give them a direct channel for contacting trained personnel who can take swift action to manage the situation effectively.