Shell UK’s Braefoot Bay terminal was cordoned off following a gas leak in the early hours of Friday morning.
Emergency services spent several hours at the plant near Dalgety Bay.
A release of propane gas was discovered and the alarm raised at around 3am.
The marine terminal is part of the Shell Fife Natural Gas Liquids (NGL) Plant, which includes its site at Mossmorran, near Cowdenbeath.
Natural gas liquids from the North Sea are separated at Mossmorran, and propane, butane and gasoline are piped to Braefoot Bay for loading onto ships for export.
The road to the terminal was closed as police and firefighters attended the incident.
It was more than seven hours before they were stood down.
A police spokesperson said: “Police in Fife supported a multi-agency response to a propane gas release at Braefoot Bay, which was detected at 3am and resolved around 10.20am today.
“Cordons were put in place locally as a precautionary measure during this time, and officers have now left the area.”