What is the purpose of adding Ethyl Mercaptan to propane?

Adding Ethyl Mercaptan to propane serves a crucial safety function by acting as a warning agent for potential gas leaks. Propane, being odorless in its natural state, poses a risk as leaks can go undetected without an identifiable smell. Ethyl Mercaptan has a strong, distinctive odor that is easily recognizable, which helps ensure that any leakage can be detected promptly. This is vital for preventing dangerous situations, as it allows individuals to take immediate action if they smell gas, such as ventilating the area or evacuating.

The other options do not accurately reflect the primary use of Ethyl Mercaptan. Enhancing fuel efficiency or combustion, or increasing heat output, pertains more to the properties of the fuel itself rather than a specific additive meant for safety. The main goal with Ethyl Mercaptan's inclusion is to prioritize the safety of users by providing a clear and detectable warning signal.