NIOSH Pocket Guide to Chemical Hazards

Potassium hydroxide

CAS 1310-58-3


RTECS TT2100000
Synonyms & Trade Names
Caustic potash, Lye, Potassium hydrate
DOT ID & Guide
1813 154 (dry, solid)
1814 154 (solution)


NIOSH REL: C 2 mg/m3
OSHA PEL†: none
IDLH N.D. See: IDLH INDEX Conversion
Physical Description
Odorless, white or slightly yellow lumps, rods, flakes, sticks, or pellets. [Note: May be used as an aqueous solution.]
MW: 56.1
BP: 2415°F
MLT: 716°F
Sol(59°F): 107%
VP(1317°F): 1 mmHg
IP: ?

Sp.Gr: 2.04
Fl.P: NA

Noncombustible Solid; however, may react with H2O & other substances
and generate sufficient heat to ignite combustible materials.
Incompatibilities & Reactivities
Acids, water, metals (when wet), halogenated hydrocarbons, maleic anhydride [Note: Heat is generated if KOH comes in contact with H2O & CO2 from the air.]
Measurement Methods
NIOSH 7401
See: NMAM or OSHA Methods
Personal Protection & Sanitation (See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated
Remove: When wet or contaminated
Change: Daily
Provide: Eyewash, Quick drench
First Aid (See procedures)
Eye: Irrigate immediately
Skin: Water flush immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Important additional information about respirator selection
Respirator Recommendations Not available.
Exposure Routes inhalation, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, respiratory system; cough, sneezing; eye, skin burns; vomiting, diarrhea
Target Organs Eyes, skin, respiratory system
See also: INTRODUCTION   See ICSC CARD: 0357