Potassium hydroxide

  • Caustic potash
  • Potassim hydrate
  • Potassim hydrate
  • Potassa
  • Potassium lye
Formula
KOH
Structure
Description
White flakes.
Uses
pH Adjustment, Fungicide, Herbicide, Microbiocide

Registry Numbers and Inventories.
CAS
1310-58-3
EC (EINECS/ELINCS)
215-181-3
EC Index Number
019-002-00-8
EC Class
Harmful; Corrosive
R 22 35
S 26 36/37/39 45
RTECS
TT2100000
RTECS class
Agricultural Chemical and Pesticide; Mutagen; Primary Irritant
UN (DOT)
1813
Merck
12,7806
Beilstein/Gmelin
19033 (G)
EPA OPP
75602
Swiss Giftliste 1
G-4504
Canada DSL/NDSL
DSL
US TSCA
Listed
Austrailia AICS
Listed
New Zealand
Listed
Japan ENCS (MITI)
Listed
Korea ECL
Listed

Properties.
Formula
HKO
Formula mass
56.11
Melting point, °C
360
Boiling point, °C
1320
Vapor pressure, mmHg
1.0 (714 C)
Odor Threshold Odor threshold Odorless
Density
2.04 g/cm3
Solubility in water
1100 g/L
Viscosity
1 cp (550 C)
Refractive index
1.409 - 1.411 (420 C)
pKa/pKb
Strong base
Thermal expansion
0.00019/K
Heat of fusion
6.72 kJ/mol
Heat of vaporization
136.0 kJ/mol

Hazards and Protection.
Storage
Store in a cool, dry place. Keep container closed when not in use. Store in a tightly closed container. Corrosives area.
D1B E
Handling
Wash thoroughly after handling. Do not allow water to get into the container because of violent reaction. Do not breathe dust, vapor, mist, or gas. Do not get in eyes, on skin, or on clothing. Keep container tightly closed. Do not ingest or inhale. Use only in a chemical fume hood. Discard contaminated shoes.
Protection
Eyes: Wear appropriate protective eyeglasses or chemical safety goggles as described by OSHA's eye and face protection regulations in 29 CFR 1910.133 or European Standard EN166. Skin: Wear appropriate protective gloves to prevent skin exposure. Clothing: Wear appropriate protective clothing to prevent skin exposure.
Respirators
A respiratory protection program that meets OSHA's 29 CFR 1910.134 and ANSI Z88.2 requirements or European Standard EN 149 must be followed whenever workplace conditions warrant a respirator's use. Follow the OSHA respirator regulations found in 29CFR 1910.134 or European Standard EN 149. Always use a NIOSH or European Standard EN 149 approved respirator when necessary.
Small spills/leaks
Vacuum or sweep up material and place into a suitable disposal container. Clean up spills immediately, using the appropriate protective equipment. Avoid generating dusty conditions. Provide ventilation.
Stability
Stable under normal shipping and handling conditions. Readily absorbs carbon dioxide and moisture from the air and deliquesces.
Incompatibilities
Halogenated hydrocarbons - halogens - nitrocompounds - organic materials - acid chlorides - acid anhydrides - magnesium - copper - generates large amounts of heat when in contact with water and may steam and splatter. Reacts with chlorine dioxide, nitrobenzene, nitromethane, nitrogen trichloride, peroxidized tetrahydrofuran, 2,4,6-trinitrotoluene, bromoform+ crown ethers, acids alcohols, sugars, germanium cyclopentadiene, maleic dicarbide. Corrosive to metals such as aluminum, tin, and zinc to cause formation of flammable hydrogen gas, moisture.
Decomposition
Oxides of potassium, hydrogen gas.

Fire.
Fire fighting
Wear a self-contained breathing apparatus in pressure-demand, MSHA/NIOSH (approved or equivalent), and full protective gear. During a fire, irritating and highly toxic gases may be generated by thermal decomposition or combustion. Wear appropriate protective clothing to prevent contact with skin and eyes. Wear a self-contained breathing apparatus (SCBA) to prevent contact with thermal decomposition products. Use water with caution and in flooding amounts. Contact with moisture or water may generate sufficient heat to ignite nearby combustible materials. Containers may explode when heated. Non-combustible, substance itself does not burn but may decompose upon heating to produce irritating, corrosive and/or toxic fumes. Extinguishing media: Use extinguishing media most appropriate for the surrounding fire. DO NOT USE WATER!
Fire potential
Nonflammable.
Hazards
Some are oxidizers and may ignite combustibles (wood, paper, oil, clothing, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated.
Combustion products
Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes.
Health
3
 
Flammability
0
 
 
Reactivity
1
 

Health.
Exposure limit(s)
TLV: ppm; 2 mg/m3 (ceiling values) (ACGIH 1993-1994). NIOSH REL: TWA 2 mg/m3
Poison_Class
2
Exposure effects
Prolonged or repeated skin contact may cause dermatitis. Prolonged or repeated eye contact may cause conjunctivitis. Effects may be delayed.
   Ingestion
Harmful if swallowed. May cause severe and permanent damage to the digestive tract. May cause circulatory system failure. May cause perforation of the digestive tract. Causes severe digestive tract burns with abdominal pain, vomiting, and possible death. May cause systemic effects.
   Inhalation
Harmful if inhaled. Irritation may lead to chemical pneumonitis and pulmonary edema. Causes severe irritation of upper respiratory tract with coughing, burns, breathing difficulty, and possible coma. Causes chemical burns to the respiratory tract. Inhalation may be fatal as a result of spasm, inflammation, edema of the larynx and bronchi, chemical pneumonitis and pulmonary edema. Aspiration may lead to pulmonary edema. May cause systemic effects.
   Skin
Causes skin burns. May cause deep, penetrating ulcers of the skin. Causes severe burns with delayed tissue destruction. Causes redness and pain. May cause skin rash (in milder cases), and cold and clammy skin with cyanosis or pale color.
   Eyes
Causes severe eye burns. May cause irreversible eye injury. Contact may cause ulceration of the conjunctiva and cornea. Eye damage may be delayed. Causes redness and pain. May cause chemical conjunctivitis and corneal damage.

First aid
 
   Ingestion
Do NOT induce vomiting. If victim is conscious and alert, give 2-4 cupfuls of milk or water. Never give anything by mouth to an unconscious person. Get medical aid immediately.
   Inhalation
Get medical aid immediately. Remove from exposure to fresh air immediately. If breathing is difficult, give oxygen. DO NOT use mouth-to-mouth respiration. If breathing has ceased apply artificial respiration using oxygen and a suitable mechanical device such as a bag and a mask.
   Skin
Get medical aid immediately. Immediately flush skin with plenty of soap and water for at least 15 minutes while removing contaminated clothing and shoes. Wash clothing before reuse. Discard contaminated clothing in a manner which limits further exposure. Destroy contaminated shoes.
   Eyes
Immediately flush eyes with plenty of water for at least 15 minutes, occasionally lifting the upper and lower eyelids. Get medical aid immediately. Do NOT allow victim to rub or keep eyes closed. Extensive irrigation is required (at least 30 minutes).

Transport.
UN number
1813
Response guide
Hazard class
8
Packing Group
II
 
USCG CHRIS Code
CPS
 
HS Code
2815 20 10
 
Std. Transport #
4932053
 
IMO Chemical Code
17
IMO Pollution Category
C
IMO Hazard code
S/P