Sodium Hydroxide vs Potassium Hydroxide (KOH)
Comprehensive comparison of Sodium Hydroxide and Potassium Hydroxide (KOH) including physical properties, applications, safety considerations, and pricing. Alliance Chemical supplies both chemicals in various grades and concentrations.
Quick Comparison Summary
Sodium Hydroxide
- CAS:
- 1310-73-2
- Formula:
- NaOH (25% solution in H₂O)
- Available:
- 25%
Physical & Chemical Properties Comparison
| Property | Sodium Hydroxide | Potassium Hydroxide (KOH) | Key Difference |
|---|---|---|---|
| Boiling Point | 105°C | 1327°C | Potassium Hydroxide (KOH) boils 1222°C higher |
| Flash Point ⚠️ | N/A | N/A | Data not available for direct comparison |
| Density | 1.271 g/cm³ | 2.044 g/cm³ | Potassium Hydroxide (KOH) is denser |
| Water Solubility | Miscible with water | 121 g/100 mL (0°C); 178 g/100 mL (25°C) | Sodium Hydroxide is more soluble |
| pH | > 12 | > 14 (1 M solution) | Sodium Hydroxide is more acidic |
| Molecular Weight | 40.00 g/mol | 56.11 g/mol | Potassium Hydroxide (KOH) is heavier molecule |
| Melting Point | N/A | 360 °C | Data not available for direct comparison |
| Vapor Pressure | N/A | N/A | Data not available for direct comparison |
| Auto-ignition Temp ⚠️ | N/A | N/A | Data not available for direct comparison |
| Vapor Density | N/A | N/A | Data not available for direct comparison |
| Appearance | Clear, colorless liquid | White or slightly yellow solid, typically available as flakes, pellets, sticks, or powder | |
| Odor | Odorless | Odorless | Similar odor |
Data sourced from PubChem (NIH), OSHA Technical Guidelines, and Alliance Chemical laboratory analysis. Last verified April 2026.
Applications & Use Cases
Sodium Hydroxide Best For:
- pH adjustment
- Chemical synthesis
- Cleaning agent
- Soap and detergent manufacturing
- Pulp and paper processing
Potassium Hydroxide (KOH) Best For:
- Soap and detergent production
- Electrolyte in alkaline batteries
- pH adjustment in wastewater treatment
- Chemical manufacturing
- Biodiesel production
Choosing Between Them
The right choice depends on your specific application, required purity, and handling capabilities. Contact our team for guidance on which chemical best fits your needs.
Safety & Handling Comparison
Storage Requirements
Always store in original containers in a cool, well-ventilated area per NFPA 30 guidelines. Refer to each product's SDS for specific storage temperature ranges and incompatible materials.
PPE Requirements
At minimum: chemical-resistant gloves, safety goggles, and adequate ventilation per OSHA 29 CFR 1910.132-138. Check each SDS below for chemical-specific PPE requirements.
Fire Hazard
Consult SDS for specific fire hazard information.
Safety Data Sheets (SDS)
Which Chemical Should You Choose?
Decision Snapshot
| Decision Factor | Better Fit | Why |
|---|---|---|
| Evaporation Profile | Sodium Hydroxide | Lower boiling point supports faster flash-off. |
| Fire Safety Margin | Check SDS | Flash-point data is incomplete for one or both products. |
| Application Breadth | Tie | Compares distinct listed use cases to avoid generic recommendations. |
| Purity Flexibility | Standard grades | Based on availability of 99%+ concentration options in current product metadata. |
Choose Sodium Hydroxide if:
- You specifically need support for ph adjustment applications.
- You specifically need support for chemical synthesis applications.
- You want a faster-evaporating solvent for quick-dry production steps.
Choose Potassium Hydroxide (KOH) if:
- You specifically need support for soap and detergent production applications.
- You specifically need support for electrolyte in alkaline batteries applications.
- You need a higher-boiling solvent that stays in-process longer.
Commercial & Fulfillment Snapshot
Built for purchasing teams that need predictable dispatch, compliant documentation, and freight flexibility from parcel to full truckload.
| Procurement Advantage | Sodium Hydroxide | Potassium Hydroxide (KOH) |
|---|---|---|
| Grade & Concentration Coverage | 25% with industrial/lab procurement support. | multiple concentration options by application with industrial/lab procurement support. |
| Packaging Depth | small packs through bulk freight quantities for parcel, pallet, and truckload planning. | small packs through bulk freight quantities for parcel, pallet, and truckload planning. |
| Dispatch SLA | Order by 1 PM CT (Mon-Thu) or noon CT Friday for same-business-day outbound from Taylor, TX. | Order by 1 PM CT (Mon-Thu) or noon CT Friday for same-business-day outbound from Taylor, TX. |
| Freight Optionality | UPS Ground for small packs plus LTL/FTL lanes through ABF, SEFL, Saia, XPO, and partner carriers. | UPS Ground for small packs plus LTL/FTL lanes through ABF, SEFL, Saia, XPO, and partner carriers. |
| Compliance Readiness | SDS ready now; COA/TDS support available pre-PO and post-order. | SDS ready now; COA/TDS support available pre-PO and post-order. |
| Bulk Procurement CTA | Request bulk quote or call (512) 365-6838. | Request bulk quote or call (512) 365-6838. |
Need Help Deciding? Our technical team can help you choose the right chemical for your specific application. Email sales@alliancechemical.com for expert guidance.
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Alliance Chemical supplies both Sodium Hydroxide and Potassium Hydroxide (KOH) in various grades and package sizes.