Used as an odorant due to its strong, unpleasant smell, 1-pentanethiol is added in trace amounts to natural gas and propane to detect leaks. It serves as a chemical intermediate in organic synthesis, particularly in the production of pharmaceuticals, agrochemicals, and specialty polymers. Its thiol group allows it to act as a chain transfer agent in radical polymerization, helping control molecular weight in polymer manufacturing. It is also employed in surface modification of nanoparticles, where it functions as a capping agent to stabilize colloidal dispersions.