The mineral supplement chloride is very different from the gas chlorine. While elemental chlorine is a dangerous gas that does not exist in the free elemental state in nature because of its reactivity, although it is widely distributed in combination with other elements. Chloride is related to chlorine however, as one of the most common chlorine compounds is common salt, NaCl. Chloride is a by-product of the reaction between chlorine and an electrolyte, such as potassium, magnesium, or sodium, which are essential for human metabolism. Chloride salts are essential for sustaining human metabolism and have none of the effects of isolated chlorine gas.