Precautions are required to prevent leaks of combustible substances from crude oil tanks. Precautions are required to prevent leaks of combustible gases, as crude oil contains easily vaporized components.

Precautions are required to prevent leaks of combustible liquids and gases. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances.

Precautions are required to prevent leaks of combustible substances. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances such as hydrogen, as well as the hydrogen sulfide produced from sulfur. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances and hydrogen sulfide. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.

Precautions are required to prevent leaks of combustible substances. Pits and enclosed spaces accessed for maintenance and inspection work may present hazards if residual gas accumulates or if the spaces fill with hazardous gas.