Sodium hydroxide

Synonyms

Aetznatron; Ascarite; Caustic soda; Caustic soda, liquid; Collo-Grillrein; Collo-Tapetta; Fuers Rohr; Hydroxyde de sodium [French]; Lewis-red devil lye; Liquid-plumr; Natrium causticum; Natrium-hydroxid, reinstes; Natriumhydroxid [German]; Natriumhydroxyde [Dutch]; Plung; Rohrputz; Rohrreiniger Rofix; Soda lye; Soda, caustic; Soda, hydrate; Soda, kaustische; Sodio(idrossido di) [Italian]; Sodium hydrate; Sodium hydrate solution; Sodium hydroxide; Sodium hydroxide (Na(OH)); Sodium hydroxide (Na2(OH)2); Sodium hydroxide dimer; Sodium(hydroxyde de) [French]; White caustic; White caustic solution; [ChemIDplus] UN1823 (solid); UN1824 (solution);

Category

Bases

Description

Colorless to white, odorless solid (flakes, beads, granular form); [NIOSH] Deliquescent; [CHEMINFO]

Sources/Uses

Used to neutralize acids, produce sodium salts, hydrolyze fats to make soaps, and precipitate metals; large amounts are used in petroleum refining, rayon production, and rubber reclaiming; [Merck Index # 8627] Also used in metal cleaning, electroplating, processing cotton fabrics, and bleaching; [ATSDR Medical Management] Used in photography (developing bath); [www.ci.tucson.az.us/arthazards/medium.html] In semiconductor manufacturing, sodium hydroxide is used to "develop" the pattern in the photoresists and also as a wet echant. [CHS, p. 44-5] Caustic soda is used in hide preparation for leather production; [PMID 21938525]

Comments

Liquid causes second or third degree burns after short contact; [CHRIS] In studies using rabbits, instillation by oral intubation caused within 10 seconds: erosion into the stomach muscle with 12% solutions; perforation with 28% solutions; and no damage with 1% solutions. Application to the skin of a 5% solution caused severe necrosis after 4 hours. Application of a 1% solution to the eyes caused no damage if the eyes were immediately irrigated. [ACGIH] Solutions > 30% are highly corrosive to skin. [Quick CPC] Inhalation of the aerosol can cause pulmonary edema. [ICSC]

Reference Link #1

Biomedical References

Insufficient data

2 mg/m3

2 mg/m3

10 mg/m3

Excerpts from Documentation for IDLHs

Human data: Workplace concentrations ranging from 2 to 8 mg/m3 have been associated with irritation of the respiratory system [Ott et al. 1977].

Reference Link #2

will not burn

0.5 mg/m3

5 mg/m3

50 mg/m3

Yes

Skin burns

Processes

Industrial Processes with risk of exposure:

• Acid and Alkali Cleaning of Metals
• Electroplating
• Leather Tanning and Processing
• Metal Extraction and Refining
• Petroleum Production and Refining
• Photographic Processing
• Semiconductor Manufacturing
• Smelting Copper or Lead
• Textiles (Fiber & Fabric Manufacturing)
• Textiles (Printing, Dyeing, or Finishing)

Activities

Activities with risk of exposure:

• Applying metallic patinas
• Textile arts