What does vacuum steam indicate about its temperature in relation to the boiling point of water?

Vacuum steam is often generated under conditions of reduced pressure, and this reduction in pressure lowers the boiling point of water. As a result, vacuum steam exists at temperatures below the standard boiling point of water, which is 100 °C at atmospheric pressure. In vacuum conditions, the boiling point can be significantly reduced, which means that the steam temperature will be less than 100 °C, indicating that it is indeed below the boiling point.

Understanding this principle is critical in process safety and management, especially in industries where steam is used for heating or sterilization, as the lower temperatures can influence the efficacy of processes and equipment design.