What color tape should be used to mark the outside potential blast zone at subsurface leaks?

Using red tape to mark the outside potential blast zone at subsurface leaks is appropriate because red is universally recognized as a color denoting danger and emergency. In safety protocols, especially in firefighting and emergency response scenarios, red tape indicates a critical area where caution is necessary due to potential hazards, such as the risk of explosions associated with gas leaks. The use of red helps team members quickly identify areas that require heightened awareness and preventive measures to avoid accidents.

In contrast, other colors like green, yellow, or blue have different standard meanings in safety contexts. Green often indicates safety or okay-to-proceed signals, yellow serves as a warning or caution for potential risks, and blue typically signifies informational or notice categories. Therefore, these colors would not effectively communicate the same level of urgency and risk associated with a potential blast zone.