What is the use of mercaptans?

Mercaptans are a group of sulfur-containing organic chemical substances. They smell like rotting cabbage, and are, for the most part, what make pulp mills smell like pulp mills. If mercaptans are in the air, even at low concentrations, they are very noticeable. Pulp mills are the chief source of mercaptans, although they are also found in production processes of some pesticides, pharmaceuticals and petroleum products. They are also used as an odourizing agent in natural gas. The human body produces them naturally during digestion of beer, garlic and some other foods.