Saltpeter is a common chemical, used for many products and science projects. Here's a look at what exactly saltpeter is.
Saltpeter is the natural mineral source of the chemical potassium nitrate, KNO3. Depending on where you live, it may be spelled "saltpetre" rather than 'saltpeter'. Before systematic naming of chemicals, saltpeter was called nitrate of potash. It has also been called 'Chinese salt' or 'Chinese snow'.
In addition to KNO3, the compounds sodium nitrate (NaNO3), calcium nitrate (Ca(NO3)2), and magnesium nitrate (Mg(NO3)2) are also sometimes referred to as saltpeter.
Pure saltpeter or potassium nitrate is a white crystalline solid, usually encountered as a powder. Most potassium nitrate is produced using a chemical reaction of nitric acid and potassium salts, but bat guano was an important historical natural source. Potassium nitrate was isolated from guano by soaking it in water, filtering it, and harvesting the pure crystals that grow. It may be produced in a similar manner from urine or manure.
Uses of Saltpeter
Saltpeter is a common food preservative and additive, fertilizer, and oxidizer for fireworks and rockets. It is one of the principal ingredients in gunpowder. Potassium nitrate is used to treat asthma and in topical formulations for sensitive teeth. It was once a popular medication for lowering blood pressure. Saltpeter is a component of condensed aerosol fire suppression systems, salt bridges in electrochemistry, heat treatment of metals, and for thermal storage in power generators.
Saltpeter and Male Libido
It's a popular myth that saltpeter inhibits male libido. Rumors abound that saltpeter has been added to food in prison and military installations to curb sexual desire, but there is no evidence to support this has been done or would even work. Saltpeter and other nitrates have a long history of medical use, but it is toxic in high doses and can produce symptoms ranging from a mild headache and upset stomach to kidney damage and dangerously altered pressure.
LeConte, Joseph (1862). Instructions for the Manufacture of Saltpeter. Columbia, S.C.: South Carolina Military Department. p. 14. Retrieved 4/9/2013.
UK Food Standards Agency: "Current EU approved additives and their E Numbers". Retrieved 3/9/2012.
US Food and Drug Administration: "Food Additives and Ingredients". Retrieved 3/9/2013.
Snopes.com: The Saltpeter Principle. Retrieved 3/9/2013.