Which of the following is a characteristic of Class I hazardous locations?

Class I hazardous locations are specifically defined by the presence of flammable gases or vapors. This classification refers to areas where the atmosphere contains materials that could be ignited and cause explosions or fires, such as gas stations, chemical plants, and oil refineries. The defining characteristic of Class I environments is their potential to have flammable gases in the air, thus making them susceptible to ignition sources.

The distinction is important: while ignitable fibers and combustible dusts are relevant to other classes of hazardous locations—such as Class II for dust and Class III for fibers—Class I is focused specifically on gases and vapors. Locations classified under Class I are subject to stringent safety regulations to mitigate the risks associated with these flammable materials, which is why understanding this classification is critical in ensuring safety and compliance in environments where such hazards are present.