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In analytical chemistry, sodium hydroxide solutions are often used to measure the concentration of acids by titration. Since NAOH is not a primary standard, solutions must first be standardised by titration against a standard such as KHP. Burettes exposed to NAOH should be rinsed out immediately after use to prevent "freezing" of the stopcock. Sodium hydroxide was traditionally uses to test for cations in Qualitative inorganice analysis. as well as to provide alkaline media for some reactions that need it, such as the biuret test.

Soap production :

Sodium hydroxide was traditionally uses in soap making. The arabs began producing soap in this way in the 7th century, and the same basic process is used today.

Paper making :

Sodium hydroxide was also widely used in making paper. Along with sodium sulfide, NAOH is a key component of the white liquor solution used to separate lignin from cellulose fibers in the Kraft process. It also plays a key role in several later stages of the process of bleaching the brown pulp resulting from the pulping process. These stages include oxygen delignification, oxidative extraction, and the simple extraction, all of which require a strong alkaline environment with a pH > 10.5 at the end of the stages.

Food preparation :

Food uses of sodium hydroxide include washing or chemical peeling of fruits and vegetables, chocolate and cocoa processing, caramel color production, poultry scalding, solf drink processing, and thickening ice cream. Olives are often soaked in sodium hydroxide to soften them, while pretzels and german lye rolls are glazed with a sodium hydroxide solution before baking to make them crisp. Due to the difficulty in obtaining food grade sodium hydroxide in small quantities for home use, sodium carbonate is often used in place of sodium hydroxide.

Domestic uses :

Sodium hydroxide is used in the home as a drain cleaning agent for clearing clogged drains. It is distributed as a dry crystal or as a thick liquid gel. The chemical mechanism employed is the conversion of grease to a form of soap. Soap is water-soluble, and can be dissolved by flushing with water. Sodium hydroxide also decomposes complex molecules such as the protein that composes hair. Such drain cleaners are highly caustic and should be handled with care.

Sodium hydroxide has been used as a relaxer to straighten hair, However, because of the high incidence and intensity of chemical burns, chemical relaxer manufacturers have now switched to other alkaline chemicals, although sodium hydroxide relaxers are still available, used mostly by professio

Cleansing agent :

Sodium hydroxide is frequently used as a cleaner in berweries, where it is simply called " caustic " It is added to water, heated, and then used to clean the large stainless steel tanks where beer is brewed, fermented and stored. It can dissolve oils and protein-based deposits.  A sodium hydroxide soak solutions is used as a powerful degreaser on stainless and glass bakeware. It also the most common ingredient in oven cleaners

Sodium Hydrosulfite is a white powder. Commercial sodium hydrosulfite contains 85% - 90% sodium dithionite w/w. It is readily soluble in water and shows powerful reducing action in aqueous solutions. Sodium hydrosulfite is used as a reducing agent in dying application. It undergoes reduction reaction with water - insoluble vat dye and sulfur dye to form water - soluble alkali metal salt of the dye so that they have affinity for the textile fiber. The reductive decomposition of the excessive dye by sodium hydrosulfite improve the colour fastness. Sodium hydrosulfite's reduction reaction removes residual oxide and wrong pigments. Sodium hydrosulfite is a reductive bleaching agent. It reduces carbonyl and alcohol groups, which function as colorants of the substances. It is used in bleaching mechanical paper pulp, cotton, wool and kaolin clay. Additional applications include water treatment, leather processing, food processing, gas purification, cleaning, printing and stripping. In addition to a reducing agent function, sodium hydrosulfite functions as a sulfonating agent and sodium ion source in a variety of chemical reactions.

Some industries that commonly rely on sodium hydrosulfite in the manufacture of their products include : Textiles, Pulp and paper, Clay, Leather, Foods and beverages, Polymers, Photographics, Chemical processin, Cleaners, Water treatment, Gas purification, Environmental improvement ...