What must be done to prevent ignition in a hazardous classified location?

To prevent ignition in a hazardous classified location, implementing grounding measures is critical. Grounding helps to ensure that any static electricity that may build up from the movement of personnel, equipment, or materials is safely discharged to the ground. This is particularly important in environments where flammable substances are present because even a small static discharge can ignite combustible vapors or dust.

Grounding systems provide a path for electrical currents to flow safely, minimizing the risk of electrical arcs that could cause an explosion. Additionally, proper grounding can help protect equipment from electrical faults and reduce the likelihood of fires initiated by electrical equipment malfunctions.

While the other options contribute to safety in various ways, they do not directly address the specific mechanism of preventing ignition caused by static electricity or electrical faults. Adequate ventilation, for example, is important for dispersing potentially explosive gases, but it does not prevent electrical ignition sources. Similarly, using standard lighting ensures appropriate visibility but does not mitigate the risks posed by static electricity or accidental electrical discharges. Restricting access is valuable for controlling who can enter hazardous areas, but it does not directly affect the ignition risks posed by electrical sources. Grounding measures, therefore, represent a fundamental and proactive step essential for safety in hazardous classified locations.