There are several things one has to remember when working with substances such as sodium hydroxide, a strong base whose chemical formula is written as NaOH. This alkaline is famous in industries due to its pH control purposes, being able to neutralize acids and acidic oxides with great efficiency. Lye or caustic soda, as it is commonly known, is used in manufacture of soaps and detergents, as well as many cleaning liquids. It is also found in processing of cotton, metals like aluminum, textile, paper, and pulp. This ionic compound dissociates completely into sodium ions and hydroxide ions in aqueous solutions.
This substance has never been found to be flammable, nor is it combustible. But since it forms extremely exothermic solutions with water, for instance, it is capable of releasing enough heat to burn combustible materials nearby when mixed with water. It also reacts with amphoteric transition metals like aluminum, tin and zinc. Typical reactions of sodium hydroxide with metals like the ones mentioned liberated hydrogen gas, which ignites in the presence of oxygen.
Storage of this compound may involve tight sealing of its containers as it reacts with acidic oxides present in the air. For instance, it strips away carbon dioxide in the air. Carbon dioxide is a natural acidic anhydride and reacts with the said alkaline to form salt called sodium carbonate.
Since this alkaline has a lower heat capacity than water, it easily transfers heat to the surroundings. For instance, mixing it with water causes dangerous heat buildup that can cause the mixture to splatter and send sprays of sodium hydroxide everywhere. Pouring water onto the solid form of this alkaline can cause a violent reaction that sends NaOH-containing aerosol into the air. Keeping in mind that the substance is a known eye, skin and respiratory irritant, such practices are extremely hazardous. In addition, the extreme heat liberated during the mixing can be enough to destroy the container and cause spillage. Thus, it is necessary to note the safe way of diluting the alkaline. The safer way is to slowly introduce the substance to water. This way, the release of tremendous heat is avoided. While pouring a concentrated NaOH into the water, gently stir the mixture to allow a quicker dissolution process and a quicker distribution of heat throughout the mixture. It is best to use cold water for this purpose. Remember this procedure is also done with concentrated acids. It is necessary to wear special clothing and protective gloves while doing this procedure. Never pour water into a concentrated solution of this alkaline. Remember also that even dilute solutions of NaOH may still cause irritation and corrosion.
The alkaline is odorless, even in aqueous solutions. This means that you may not immediately notice your exposure until after irritation occurs. Thus, you may already be dangerously in contact with the alkaline without ever noticing it. This should prompt for extra caution when working with the chemical.
The extreme corrosiveness and reactivity of this substance warrants workers with high chances of coming in contact with this compound as well as to check engineering controls in the area they are working in. Safety equipment and protective gears and clothing must be available at all times. It is a basic rule to follow hygiene guidelines. Workers who are constantly running the risk of exposure with this chemical must be educated and informed about its properties and its health hazards. Furthermore, they must be trained in handling the chemical carefully.
Proper ventilation must be present in working areas. Should leaks and spillage be seen in containments, immediately report this problem. Before carrying and transporting containers check for leaks and damage.
There are several materials that must be kept away from this substance. Never place strong acids with the base, let alone mix them together. NaOH should not come in contact with nitroaromatic, nitroparaffinic or organohalogen compounds. As mentioned earlier the alkaline reacts with metals like aluminum, tin and zinc. Thus, it must not be transported in aluminum containers, for instance, as this may result to liberation of combustible hydrogen gas and damage to the aluminum container. Furthermore, it also reacts with glass. Hence, glass containers are not suitable for prolonged storage of the compound.