Nitrate refers to a chemical compound that contains the nitrate ion (NO3-), which is a polyatomic anion formed by the combination of one nitrogen atom and three oxygen atoms. Nitrates are typically formed from the reaction of nitric acid (HNO3) with a base or a metal. As a result, nitrates are commonly found as salts of nitric acid, such as potassium nitrate (KNO3) or calcium nitrate (Ca(NO3)2). Nitrates have several applications, including as fertilizers in agriculture, food preservatives, and in the production of explosives. However, excessive intake of nitrates can be harmful to human health as they can convert into nitrites, which can interfere with the oxygen-carrying capacity of red blood cells and cause methemoglobinemia, a condition where the blood cannot carry enough oxygen to the body’s tissues.