Potassium nitrate, also known as saltpeter, is an odorless powder composed of transparent and/or white crystals. It is prepared commercially for use in a number of products, including gunpowder, fireworks, matches, rocket propellants, ceramics, glass and fertilizers. It is also used as a food preservative, and can be found in cured meats, cheeses and toothpaste, according to Chemicalland21.com. While saltpeter is considered to be a stable compound in normal conditions, it has some unique chemical properties that can pose risks, and should be handled with care.
While potassium nitrate itself is not combustible, it is considered to be a strong oxidizer, meaning that it releases oxygen when it breaks down, or decomposes. This oxygen release greatly enhances the flammability of other materials. Potassium nitrate also emits heat when it decomposes, so it may provide a source of ignition if stored with flammable materials. Potassium nitrate also gives off toxic fumes when in a fire. Fire safety precautions include storing saltpeter away from combustibles. All fire extinguishing agents are safe to use in the event of a fire involving potassium nitrate.
Reducing agents are compounds that cause a chemical reaction, called a redox reaction, when they come into contact with an oxidizing agent such as potassium nitrate. Because potassium nitrate is such a strong oxidizer, the redox reaction produced with certain chemicals may cause an explosion. While this property of saltpeter is exploited when using it to produce pyrotechnics, matches and gunpowder, safety precautions should be taken in their handling and storage. Chemicalland21.com recommends that all reducing agents be stored separately from potassium nitrate.
Potassium nitrate can pose a number of health risks. When inhaled, it may cause respiratory problems, including coughing and shortness of breath. Skin or eye contact may result in irritation such as redness, itching and pain. If ingested, a number of problems can occur, including blue lips and fingernails, abdominal pain, dizziness, nausea, vomiting and diarrhea. Mallinckrodt Baker Chemicals advises that workers wear masks, gloves and safety goggles when handling potassium nitrate powder. First aid measures involve removing exposed persons to fresh air, flushing any areas of contact with water, inducing vomiting if potassium nitrate ingestion has occurred, and seeking immediate medical attention.