Dimethyl sulfoxide (DMSO) is widely used due to its excellent solvent properties; however,
several serious incidents have been reported related to the use of DMSO. DMSO can
decompose autocatalytically, but we have no consensus with respect to the chemical
structure and function of the autocatalyst. Thermal decomposition of DMSO was carried out
in an inert atmosphere, and analysis of the nonvolatile fraction indicated the presence of
several organic and inorganic acids. DMSO was believed to act as an oxidizer as well as a …

Dimethyl sulfoxide (DMSO) is a good solvent as well as a mild oxidizing agent. Several
severe incidents associated with DMSO decomposition have been reported in spite of its
wide use. The goal of this study is to understand the early stage of DMSO decomposition. In
repeated isothermal heating tests of DMSO in an inert atmosphere, two kinds of intermediate
substances were found: one contained labile, turbid compounds in the liquid phase, and the
other was a white material deposited on the inner wall of the headspace. Analyses of these …