Lydia this side...Mercaptans, also known as thiols, are gaseous compounds that form when organic matter degrades in anaerobic conditions. These molecules have a similar structure to phenols and alcohols, but instead of oxygen, they have a sulfur atom. Owners are increasingly realizing that treating odors from organic reduced sulfur compounds, particularly Mercaptan removal is necessary as populations shift to outlying industrial and municipal facilities.For further detail have a look on website.