Final answer:
It is unsafe to re-enter a fuel truck once fueling has started due to the risk of generating static electricity, the inability to monitor gauges, lack of immediate access to the emergency shut-off, and not being able to see a potential fuel leak.
Step-by-step explanation:
There are several reasons why one should not re-enter the fuel truck after initiating fueling:
- You may generate a static charge on your person, which is dangerous in the presence of flammable fuel vapors.
- You cannot monitor gauges, which is necessary to ensure safe and proper fueling.
- You will not have immediate access to the Emergency Fuel Shut-Off Device (EFSO), which is critical in case of an emergency or fuel leak.
- Lack of visibility prevents you from identifying a potential fuel leak, which can be hazardous.
Static electricity, especially in the context of fueling operations, poses a significant risk. For instance, turning on a light switch can cause a negligible amount of static electricity, but this is not typically a concern. However, when dealing with flammable liquids like gasoline, static electricity can be very dangerous due to the potential ignition of gasoline vapors. The example of dispersing a charged drop of gasoline emphasizes the dangers of ungrounded gasoline pumps, which can contribute to the build-up of static charge, increasing the risk when refueling.