Which of the following is a strong-smelling agent added to LPG cylinders to help detect gas leakage?

Liquefied Petroleum Gas (LPG) is widely used as a fuel for domestic, commercial, and industrial purposes. It is a mixture of hydrocarbons, mainly propane and butane. In its pure form, LPG is colorless and odorless, making it extremely dangerous because any leak can go unnoticed. To ensure safety, a strong-smelling chemical called ethyl mercaptan (C₂H₅SH) is added to LPG as an odorant.

Ethyl mercaptan has a distinct, pungent smell similar to rotten cabbage or garlic. This characteristic odor helps users immediately detect even a small gas leak, allowing them to take quick action before an explosion or fire occurs. The human nose is very sensitive to this compound; it can detect ethyl mercaptan even when it is present in very low concentrations, making it an ideal choice for this purpose.

Chemically, ethyl mercaptan is an organic sulfur compound belonging to the family of thiols. The presence of sulfur gives it its strong odor. When mixed with LPG, it does not affect the burning properties or efficiency of the gas. Instead, it serves purely as a safety measure. In case of a leak, the released gas carries the smell of ethyl mercaptan, providing an immediate warning to the occupants of a building or facility.

The addition of ethyl mercaptan is mandatory in many countries to prevent accidental deaths and explosions due to undetected leaks. Safety instructions often advise users to never ignore the smell of gas, to avoid lighting flames, and to immediately switch off gas regulators and ventilate the area.

In summary, ethyl mercaptan is the strong-smelling agent added to LPG cylinders to help detect gas leakage. Its distinctive odor acts as a simple yet effective safety mechanism, protecting lives and property by ensuring early detection of potentially hazardous gas leaks.