When gas is exposed to voltages higher than its insulating properties, arcing can occur. An arc is formed when the voltage is sufficient to ionize the air between the conductors. Ionized air becomes an excellent conductor and conducts electricity. The ionization of the air creates electrical currents that produce heat and blinding light. This heat causes the ionized air to rise, creating an arcing flow, hence the name of the phenomenon. Arc flash can produce temperatures up to 20,000 degrees Celsius.

When a gas is exposed to a voltage greater than its insulating capabilities, electrical arcs result. The arc begins when the voltage is high enough to ionize the space between the conductors. A gas becomes a great conductor when it is ionized, allowing current to flow and producing the arc-shaped current known as an arc flash. Unintentional electrical discharge that results in a fire is known as an arc fault.