A chemist forgot to wash his hands — and discovered a sweetener that survived a ban

In 1879, Constantin Fahlberg, a chemist working in Ira Remsen's laboratory at Johns Hopkins University, was studying the oxidation of o-toluenesulfonamide, a coal tar derivative. One evening, he sat down to dinner without washing his hands and noticed his bread tasted unusually sweet. He traced the sweetness back to a compound he had been working with that day — benzoic sulfimide, 300 to 500 times sweeter than sugar.

Fahlberg and Remsen published their findings in 1879 and 1880. In 1884, Fahlberg applied for patents on his own, naming the substance saccharin (from Latin 'saccharum', sugar). He began production in a factory near Magdeburg, Germany, and grew wealthy. Remsen, who felt he deserved shared credit, was embittered: 'Fahlberg is a scoundrel. It nauseates me to hear my name mentioned in the same breath with him.'

Saccharin became widely used during World War I, when sugar shortages made it a valuable alternative. Its popularity grew among dieters in the 1960s and 1970s. In 1977, the FDA proposed a complete ban after studies showed saccharin caused bladder cancer in rats. Public outcry, driven by industry advertisements, defeated the ban. Instead, a warning label was required until 2000.

Further research determined the cancer mechanism was specific to rats — it did not apply to humans. Epidemiological studies found no evidence of bladder cancer in humans at typical intake levels. The EPA removed saccharin from its hazardous constituents list in 2010. Today, saccharin remains one of the most studied and safest artificial sweeteners in use.