What action must be taken at all entrances to places with dangerous conditions?

Placing a conspicuous danger sign at all entrances to places with dangerous conditions is crucial because it serves as a clear and immediate alert to anyone approaching the area. Signage plays a vital role in hazard communication, helping to inform workers and visitors about the specific risks present, which can range from structural hazards to chemical exposures.

The visibility and presence of a danger sign ensure that individuals are made aware of the potential dangers before they enter the area, allowing them to make informed decisions about their safety. It is fundamentally important to keep these warnings clear and distinct to prevent accidents and ensure compliance with safety regulations.

Other actions, while important in their contexts, do not provide the same immediate communication of risk that a conspicuous danger sign offers. For instance, warning lights might not be as noticeable in all environments, closing off access points could hinder legitimate work operations, and deploying safety personnel may not be feasible or necessary if just signposting can effectively safeguard the area.