Sodium Hydroxide


CAS No. 1310-73-2

Sodium hydroxide (NaOH) is a an odorless, white crystalline solid that absorbs moisture from the air. Sodium hydroxide is very corrosive. It can cause irritation to the eyes, skin, and mucous membrane; an allergic reaction; eye and skin burns; and temporary loss of hair. Workers may be harmed from exposure to sodium hydroxide. The level of harm depends upon the dose, duration, and work being done.

Sodium hydroxide is used to manufacture soaps, rayon, paper, explosives, dyes, and petroleum products. It is also used in processing cotton fabric, laundering and bleaching, metal cleaning and processing, oxide coating, electroplating, and electrolytic extracting. It is commonly present in commercial drain and oven cleaners.

Some examples of workers at risk of being exposed to sodium hydroxide include the following:

  • Workers who use bleach, oven cleaners, and drain cleaners
  • Workers in food processing plants
  • Workers in public water treatment facilities
  • Workers who use it for a diverse range of industrial and manufacturing processes
  • Workers who extract alumina and produce aluminum

NIOSH recommends that employers use Hierarchy of Controls to prevent injuries.  If you work in an industry that uses sodium hydroxide, please read chemical labels and the accompanying Safety Data Sheet for hazard information. Visit NIOSH’s page on Managing Chemical Safety in the Workplace to learn more about controlling chemical workplace exposures.

The following resources provide information about occupational exposure to sodium hydroxide. Useful search terms for sodium hydroxide include “lye,” ” caustic soda,” “soda lye,” and  ” sodium hydrate.”

NIOSH Chemical Resources

Related NIOSH Resources

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International Resources

Page last reviewed: June 21, 2019