In its natural room-temperature state, caustic soda is a solid, but since it readily dissolves in water, it is often sold and transported as a solution of varying concentrations. When caustic soda is mixed with water or an acid, there is a strong exothermic reaction where heat is released, which can be used as a source of energy to trigger other chemical processes. In many lye-related chemical reactions (as was mentioned with soap) caustic soda gives up its sodium, hydrogen and oxygen atoms to help form new chemical compounds. In situations where a corrosive substance is required, like for a drain blockage, caustic soda will work to dissolve the organic materials but will leave the PVC pipes intact. Sodium hydroxide is also used in the production of soft drinks, ice cream and food dye. The corrosive and toxic properties of caustic soda disappear in these processes such as the case with soap above.
It’s important to note that sodium hydroxide is not safe for direct consumption. It should never be ingested and can cause severe injury or death. Food companies rigorously train their employees in the safe use of sodium hydroxide in chemical food preparation processes, and the end products are tested before being placed on the market.
Post time: Jul-15-2019