What is the definition of a gas free tank?

A gas free tank is defined as a tank that is free of hydrocarbons and noxious vapors. This is crucial for safety when performing maintenance, inspection, or any operations related to the tank. Ensuring there are no hydrocarbons or harmful vapors mitigates the risk of fire, explosion, or exposure to toxic substances, which can pose serious health hazards to personnel.

In the context of tank operations, being "gas free" allows workers to enter the tank without specialized breathing apparatus or additional safety measures that would be necessary if hazardous vapors were present. It's a critical concept in the management of fuel and chemical tanks, ensuring they can be handled safely without compromising the health and safety of the crew.

The other options refer to conditions that are not safe for personnel. For example, a tank containing hydrocarbons only or one that contains vapors would pose risks and would require further action to ensure safety before anyone could work within those confines. Similarly, a tank filled with inert gases does not necessarily mean it is free of hydrocarbons or harmful vapors. Thus, the importance of understanding what "gas free" entails is vital for proper tank management and safety protocols.