Under which article would you find regulations for hazardous classified locations?

The correct article that governs regulations for hazardous classified locations is Article 500, which is often related to articles like 510 through 516 that focus on more specific classifications of environments. However, among the provided choices, Article 510 specifically addresses the classification and requirements related to "Hazardous (Classified) Locations." This includes locations where flammable gases, vapors, or dusts are present and outlines the necessary precautions and installation practices to ensure safety in these environments.

The other articles listed focus on different aspects of hazardous locations. For example, Article 511 pertains specifically to locations classified as hazardous due to the presence of flammable liquids. Article 513 primarily involves the requirements for the use of containers for combustible materials. Article 516 addresses areas where hazardous gases or vapors could be present, but it is not the overarching classification article like Article 510, which encapsulates the broader regulations concerning hazardous locations.