Saccharin by Ray Sahelian, M.D.

Saccharin is 200 to 600 times as sweet as sugar and has no calories. Brand names include Sweet'N Low, Sweet Twin, and Necta Sweet. Saccharin is used in tabletop sweeteners, baked goods, soft drinks, jams, and chewing gum.

The word saccharin has no final "e". The word saccharine, with a final "e", is much older and is an adjective meaning "sugary". Saccharin has an unpleasant bitter or metallic aftertaste, especially at high concentrations. Unlike the newer artificial sweetener aspartame, saccharin is stable when heated, even in the presence of acids, does not react chemically with other food ingredients, and stores well. Blends of saccharin with other sweeteners are often used to compensate for each sweetener's weaknesses.

Saccharin alternative
There are many natural sweeteners that can be used instead of saccharin. My favorite is stevia.
 

Safety of Saccharin
Saccharin was discovered in 1879 and had been considered generally recognized as safe (GRAS) until 1972, when it was removed from the GRAS list by the FDA. By definition in the law, a GRAS substance has a long history of safe use in foods, or is determined to be safe based on proven science. But if new evidence suggests that a GRAS substance may no longer be safe, the FDA can prohibit its use or require further safety studies.
     In 1977, the FDA proposed a ban on saccharin because of concerns about rats that developed bladder cancer after receiving high doses of saccharin. In response, Congress passed the Saccharin Study and Labeling Act. This legislation put a moratorium on the ban while more safety studies were under way. Also, foods containing saccharin were required to carry a label warning that the sweetener could be a health hazard and that it was found to cause cancer in laboratory animals. Saccharin has been the subject of more than 30 studies in humans.
     According to the National Cancer Institute, further studies showed that saccharin did not cause cancer in humans, and that the bladder tumors in rats were related to a mechanism that isn't relevant for humans.
     In 2000, the National Toxicology Program determined that saccharin should no longer be listed as a potential cancer-causing agent. Federal legislation followed in 2001, removing the requirement for the saccharin warning label.