Sodium Hydroxide


CAS No. 1310-73-2

Sodium hydroxide (NaOH) has no smell. It is made of solid white crystals that absorb water from the air. Sodium hydroxide is caustic. Workers who come in contact with sodium hydroxide can be harmed. The level of harm depends upon the amount, duration, and activity. It can burn the eyes, skin, and inner membranes, and cause temporary hair loss.

Sodium hydroxide is used to produce soaps, rayon, paper, products that explode, dyes, and petroleum products. It can also be used in tasks such as processing cotton fabric, metal cleaning and processing, oxide coating, electroplating, and electrolytic extraction. It is often found in commercial drain and oven cleaners.

Some examples of workers who are at risk of being exposed to sodium hydroxide include those who

  • Use bleach, oven cleaners, and drain cleaners
  • Work in food processing plants
  • Work in public water treatment plants
  • Use sodium hydroxide for making paper, glass, detergents, soaps, and other products
  • Mine alumina and produce aluminum

NIOSH recommends that employers use a Hierarchy of Controls to prevent injury.  If you work in an industry that uses sodium hydroxide, please read the chemical label and the Safety Data Sheet for information on how it can harm you and how to protect yourself. Visit NIOSH’s page on Managing Chemical Safety in the Workplace to learn more about preventing contact with chemicals in the workplace.

The following resources provide information about workplace 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

Selected Publications

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International Resources

Page last reviewed: June 28, 2021