Used as a trace gas and an oxygen asyphxiant in aluminum foundry application in reduction of porosity, replacing corrosive and toxic chlorine processes. A unique specialty gas product for which no other gas has been found suitable for replacement. Sulfur forms a wide variety of compounds with halogen elements. In combination with chlorine it yields sulfur chlorides such as disulfur dichloride, S2Cl2, a corrosive, golden-yellow liquid used in the manufacture of chemical products. It reacts with ethylene to produce mustard gas, and with unsaturated acids derived from fats it forms oily products that are basic components of lubricants.
Sulfur also forms oxyhalides, in which the sulfur atom is bonded to both oxygen and halogen atoms.