Sulfur

Though many of us find the smell of sulfur extremely irritating, we should be grateful for its characteristic odour. The presence of this element in scentless, combustible gases makes possible the detection of gas leaks. In fact, sulfur's unpleasant odour provides a signal that saves the lives of many.

In its solid form, sulfur is pale yellow, odourless and brittle. This element occurs in large deposits as yellow crystals, and the sulfate ion is often found in spring water.

Some of its more significant industrial compounds are hydrogen sulfide, sulfur dioxide, and sulfuric acid. Sulfur dioxide possesses a suffocating smell, and contributes to atmospheric pollution and acid rain. Sulfuric acid is an important manufactured chemical used in the synthesis of fertilizers as well as in car batteries.

Biologically, sulfur plays important roles. It is present as a minor constituent of fats, and its sulfates are bound to other organic compounds in the body. Further, many disulfide linkages – the interaction between two sulfur atoms – hold proteins in their proper shape. This is why sulfur is an important ingredient in permanent hair waving liquids. The strong bonds that the sulfur atoms form with one another hold the hair – made largely of the protein keratin – in its "permed," wavy state.