Caustic Soda (all grades)

CAS:  1310-73-2

Synonyms:    Lye; Soda Lye; Sodium Hydroxide; Caustic Soda beads; Caustic Soda Flakes; Caustic Soda pellets; Sodium Hydroxide, Liquid; Sodium Hydroxide Solution; Caustic Soda, liquid; Caustic Soda Solution.

Uses:    Chemical manufacture; neutralizing agent in petroleum refining; pulp and paper; aluminum; detergents; soap; textiling processing; vegetable-oil refining; reclaiming rubber; regenerating ion exchange resins; organic fusions; peeling of fruits and vegetables in food industry; lab reagent; etching and electroplating; food additive; utilities; water treatment/sanitation.

Hazard:    Strong corrosive action on contacted tissues.  INHALATION: dust may cause damage to upper respiratory tract and lung itself, producing from mild nose irritation to pneumonitis.  INGESTION:  severe damage to mucous membranes; severe scar formation or perforation may occur.  EYE CONTACT:  produces severe damage. 

CAUSTIC SODA (Sodium hydroxide) is a strong base.  Reacts rapidly and exothermically with acids, both organic and inorganic. Readily absorbs moisture from the air to give caustic semi-solids that attack aluminum and zinc with the evolution of flammable hydrogen gas. Catalyzes the polymerization of acetaldehyde and other polymerizable compounds; these reactions can occur violently, for example, acrolein polymerizes with extreme violence when put in contact with alkaline materials such as sodium hydroxide.  Reacts with great violence with phosphorus pentaoxide when initiated by local heating.  Contact (as a drying agent) with tetrahydrofuran, which often contains peroxides, may be hazardous—explosions have occurred in such a use of the chemically similar potassium hydroxide. Mixing with any of the following substances in a closed container caused the temperature and pressure to increase: glacial acetic acid, acetic anhydride, acrolein, chlorohydrin, chlorosulfonic acid, ethylene cyanohydrin, glyoxal, hydrochloric acid (36%), hydrofluoric acid (48.7%), nitric acid (70%), oleum, propiolactone, sulfuric acid (96%) [NFPA 1991].   Accidental contact between a caustic cleaning solution (probably containing sodium hydroxide) and Pentol caused a violent explosion.   Heating with a mixture of methyl alcohol and trichlorobenzene during an attempted synthesis led to a sudden increase in pressure and an explosion. Hot and/or concentrated NaOH can cause hydroquinone to decompose exothermically at elevated temperature.