less than 7 nM in blood, less than 3 nM in urine and 0.13 to 0.65 nM on expired breath. At pathologically dangerous concentrations, this is known as dimethylsulfidemia. This condition is associated with blood borne halitosis and dimethylsulfiduria. In people with chronic liver disease (cirrhosis), high levels of dimethyl sulfide may be present in the breath, leading to an unpleasant smell (fetor hepaticus). Odor Dimethyl sulfide has a characteristic odor commonly described as cabbage-like. It becomes highly disagreeable at even quite low concentrations. Some reports claim that DMS has a low olfactory threshold that varies from 0.02 to 0.1 ppm between different persons, but it has been suggested that the odor attributed to dimethyl sulfide may in fact be due to disulfides, polysulfides and thiol impurities, since the odor of dimethyl sulfide is much less disagreeable after it is freshly washed with saturated aqueous mercuric chloride. Dimethyl sulfide is also available as a food additive to impart a savory flavor; in such use, its concentration is low. Beetroot, asparagus, cabbage, corn and seafoods produce dimethyl sulfide when cooked. Dimethyl sulfide is also produced by marine planktonic microorganisms such as the coccolithophores and so is one of the main components responsible for the characteristic odor of sea water aerosols, which make up a part of sea air. In the Victorian era, before DMS was discovered, the origin of sea air's 'bracing' aroma was attributed to ozone. Industrial uses Dimethyl sulfide is considered the most important thioether produced industrially. One major use is for the production of borane dimethyl sulfide from diborane: Oxidation of dimethyl sulfide gives the solvent dimethyl sulfoxide. Further oxidation affords dimethyl sulfone. Chemical reactions As illustrated above by the formation of its adduct with borane, dimethyl sulfide is a Lewis base. It is classified as a soft ligand (see also ECW model). It forms complexes with many transition metals but such adducts are often labile. For example, it serves a displaceable ligand in chloro(dimethyl sulfide)gold(I). Dimethyl sulfide is used in the workup of the ozonolysis of alkenes. It reduces the intermediate trioxolane. The Swern oxidation produces dimethyl sulfide by reduction of dimethylsulfoxide. With chlorinating agents such as sulfuryl chloride, dimethyl sulfide converts to chloromethyl methyl sulfide: Like other methylthio compounds, DMS is deprotonated by butyl lithium: Safety Dimethyl sulfide is highly flammable and an eye and skin irritant. It is harmful if swallowed. It has an unpleasant