What is an essential feature of all filling stations according to safety standards?

A locking closure device on fill openings is crucial for safety at filling stations because it helps prevent unauthorized access to fuel tanks and reduces the risk of spills and contamination. This feature ensures that only trained personnel can access the fill openings, which is important for maintaining safety standards and protecting the environment. By securely locking these openings, the station minimizes the chances of accidents or leaks that could lead to hazardous situations.

While visual surveillance systems, automatic shut-off valves, and manual fuel shut-off mechanisms are valuable safety features in their own right, the locking closure device specifically addresses the issue of access control, which is essential in maintaining the integrity of the fuel storage system and preventing accidental or deliberate discharges of fuel. Hence, it stands out as an essential feature at all filling stations according to safety standards.