Caustic Potash (Potassium Hydroxide)
High purity strong base used in soap production, fertilizer industry, chemical manufacturing and industrial applications
Overview
Caustic Potash (Potassium Hydroxide, CAS No: 1310-58-3) is a strong basic chemical widely used in various industrial applications. It appears as a white, hygroscopic solid and has high solubility in water.
Potassium hydroxide can be considered as the potassium equivalent of sodium hydroxide (caustic soda) but shows different properties in some applications. Its chemical formula is KOH and its molecular weight is 56.11 g/mol. It is a versatile chemical used in many industrial, chemical and agricultural applications.
Applications
Caustic Potash has a wide range of industrial and commercial applications:
Soap Production
Used in saponification of fats to produce liquid and soft soaps. Potassium soaps are softer than sodium soaps.
Fertilizer Industry
Used in production of potassium-containing fertilizers and as soil pH regulator. Provides a source of potassium, an important nutrient for plants.
Chemical Production
Used as raw material in production of potassium carbonate, potassium phosphates and other potassium salts.
Petroleum Refining
Used in petroleum refining to remove acidic impurities. Also acts as catalyst in processing of some petroleum products.
Battery Production
Used as electrolyte in alkaline batteries. Potassium hydroxide solutions show high conductivity.
Other Applications
Used in paint production, textile processing, food processing (as pH regulator), cleaning products and chemical cleaning applications.
Technical Specifications
| Property | Value | Unit | Test Method |
|---|---|---|---|
| Chemical Formula | KOH | - | - |
| CAS Number | 1310-58-3 | - | - |
| EC Number | 215-181-3 | - | - |
| Molecular Weight | 56.11 | g/mol | - |
| Appearance | White pellets/solid | - | Visual |
| Odor | Odorless | - | - |
| Density (25°C) | 2.04 | g/cm³ | ASTM D4052 |
| Melting Point | 360-406 | °C | ASTM D1015 |
| Boiling Point | 1327 | °C | ASTM D2887 |
| Water Solubility (20°C) | 1210 | g/L | ASTM E1148 |
| pH Value (0.1M sol.) | 13.5 | - | ASTM E70 |
| Purity | ≥90% | % | ASTM E291 |
| Carbonate (K₂CO₃) | ≤2.0% | % | Titration |
| Chloride (Cl) | ≤0.01% | % | ASTM E291 |
| Sulfate (SO₄) | ≤0.002% | % | ASTM D516 |
| Heavy Metals (Pb) | ≤10 | ppm | ASTM E1613 |
Safety Information
Hazard Symbols and Statements
Corrosive Irritant Health Hazard Environmental Hazard
Personal Protective Equipment (PPE)
- Chemical-resistant gloves (nitrile or neoprene)
- Face shield or goggles
- Acid-base resistant apron
- Dust mask or respirator (when working in powder form)
- Protective footwear
Storage Conditions
- Store in a cool, dry and well-ventilated place
- Protect from air moisture and carbon dioxide
- Keep in tightly closed containers
- Keep away from acids and water reactive materials
- Storage temperature: Room temperature (15-30°C)
Fire Fighting
- Suitable extinguishers: Dry chemical, CO₂, dry sand
- Do not use water (risk of exothermic reaction)
- Toxic gases (potassium oxide fumes) may be released in case of fire
- Fire fighting personnel should use full protective equipment
Handling and Storage
Handling
- Ensure containers are tightly closed
- Avoid exposure to acids and moisture
- Take measures to prevent tipping during transport
- Have neutralizing material (weak acid) available in case of spillage
- Provide adequate ventilation in transport vehicles
Storage
- Store in polyethylene, stainless steel or nickel containers
- Do not allow contact with metals such as aluminum, tin, zinc and lead
- Keep appropriate signs in storage areas
- Have acid neutralizing material available in storage areas
- Provide secondary containment for large quantities stored
Measures in Case of Spillage
- Evacuate exposed personnel from the area
- Use appropriate personal protective equipment
- Clean without raising dust into the air
- Neutralize with weak acid (such as vinegar)
- Wash spilled area with plenty of water (after neutralization)
- Comply with local regulations for waste disposal
Regulatory Information
GHS Classification
- Skin Corrosive/Category 1A
- Serious Eye Damage/Category 1
- Acute Toxicity (Oral)/Category 4
- Acute Hazard to Aquatic Environment/Category 1
Important Regulations
- REACH: Registered
- CLP: Compliant
- OSHA: Hazardous Material Standard (29 CFR 1910.1200)
- EPA: On TSCA List
Industrial Standards
- ASTM E291: Standard Test Methods for Industrial Chemicals
- ISO 979: Potassium Hydroxide Technical Grade - Properties
- USP-NF: Grade available meeting pharmaceutical quality standards
Environmental Information
Environmental Impact
Potassium hydroxide may cause harmful effects in aquatic environments by creating high pH. It neutralizes in soil and potassium ions can be absorbed by plants. In high concentrations it may damage soil microorganisms.
Biological Degradation
- Water: Dissociates rapidly into ions, not biodegradable
- Soil: Neutralizes and releases potassium ions
- Air: May react with moisture forming potassium carbonate
Waste Management
- Classified as hazardous waste
- Can be disposed of by neutralizing with weak acids (such as vinegar)
- Should not be discharged directly to sewer or surface waters
- Should be sent to licensed hazardous waste disposal facilities
- Dispose of in accordance with local regulations
Frequently Asked Questions
What is the difference between caustic potash and sodium hydroxide?
Caustic potash (KOH) and sodium hydroxide (NaOH) are strong alkalis but have different applications. KOH is more expensive but produces softer soaps and is more soluble in alcohol. NaOH is more common and economical, preferred for solid soaps.
What should I do if caustic potash comes into contact with skin?
Wash immediately with plenty of water for at least 15 minutes. Remove contaminated clothing. If irritation or burn continues, seek medical help. Do not use acid (such as vinegar) to neutralize, use only water.
How should caustic potash be stored?
It should be protected from air moisture and CO₂, stored in tightly closed containers. Plastic (polyethylene or polypropylene) or stainless steel containers are suitable. Aluminum, tin or zinc containers should not be used.
Can caustic potash be used in foods?
Yes, food grade potassium hydroxide (E525) is used in some food processing applications (such as cocoa processing, olive preparation) as pH regulator. However, industrial grade KOH that is not food grade should not be used in foods.
What to do if caustic potash is inhaled?
Move affected person to fresh air. If breathing is difficult, administer oxygen and seek immediate medical help. In case of dust inhalation, keep person calm and avoid movement.