What is the required signage for a laboratory storing potentially hazardous substances?

The appropriate signage for a laboratory storing potentially hazardous substances is one that clearly warns individuals about the presence of these hazardous materials. The option selected is effective because it includes the term "Caution," signaling to anyone entering the space that there are dangers present, and underscores the need for attentiveness and care.

This specific wording allows for immediate recognition of the laboratory's nature and the risks involved, making it essential for both safety and regulatory compliance in environments where hazardous substances are handled. It emphasizes the potential hazards without creating unnecessary alarm, which is important for maintaining a balance between awareness and fear.

The other options do not convey the same level of warning or specificity regarding the hazards present. While "Laboratory - Hazardous Chemicals" might also indicate risks, it lacks the cautionary appeal that directly instructs individuals to be aware and careful. "Laboratory - Safe Zone" is misleading, as it implies safety rather than the potential dangers. Lastly, "Laboratory - No Entry" may prevent access entirely, which does not serve the purpose of informing about potential hazards while still allowing for necessary work to continue under safe practices. Thus, the chosen option effectively meets the need for clear and proper signage in such environments.