A tank or compartment is considered gas free when there is an absence of dangerous concentrations of what?

A tank or compartment is deemed gas free when it contains no dangerous concentrations of flammable or toxic gases. This is crucial for ensuring safety during maintenance or inspection operations, as the presence of such gases can lead to potentially lethal situations, including explosions or poisoning.

Flammable gases pose an immediate risk of ignition, which can have catastrophic consequences if there is a source of ignition present. Toxic gases, on the other hand, can compromise the health of personnel working in or near the tank, potentially leading to serious health issues or fatalities. Therefore, confirming the absence of both flammable and toxic gases is essential to maintain a safe environment.

When tanks are being prepared for entry or maintenance, strict protocols are followed to measure the concentration levels of gases and ensure they fall below hazardous limits. This ensures the safety of personnel and the integrity of the operational environment.