Which type of liquid is classified as Class I in hazardous locations?

Class I liquids are those that have a flashpoint below 100°F (37.8°C) and are capable of forming ignitable vapors at normal temperatures. Alcohol is primarily classified in this category due to its low flashpoint. When considering the potential hazards associated with different liquids, alcohol can easily release vapors that might ignite, especially in environments where there are sources of ignition present.

Water does not fall under Class I as it is not flammable. Oils and automotive fluids, while they can pose a danger, typically have higher flashpoints and may fall under different classifications, often Class II or Class III, depending on their specific properties. Thus, alcohol stands out as the correct choice for Class I due to its ability to ignite at lower temperatures, making it a significant hazard in certain settings.