Products Description
Methanesulfonic Acid (MSA), CAS No. 75-75-2, is a strong, non-oxidizing organic acid commonly available in 70% aqueous solution and 99% anhydrous grades. It is typically a colorless, clear liquid with low volatility and little to no odor. MSA is highly soluble in water, alcohols, and ethers, but insoluble in alkanes, benzene, toluene, and other non-polar solvents. It exhibits excellent thermal stability, remaining stable in boiling water and hot alkaline conditions. However, it is highly corrosive to metals, including iron, copper, and lead. Due to its strong acidity and chemical properties, MSA is widely used in industrial applications. It is classified as UN3265, Class 8 (Corrosive), Packing Group II.
Chemical Properties
| Melting point | 17-19 °C (lit.) |
| Boiling point | 167 °C/10 mmHg (lit.) |
| density | 1.475-1.485 g/mL at 20 °C 1.481 g/mL at 25 °C (lit.) |
| vapor density | 3.3 (vs air) |
| vapor pressure | 1 mm Hg ( 20 °C) |
| refractive index | n20/D 1.429(lit.) |
| Fp | >230 °F |
| storage temp. | 2-8°C |
| solubility | water: soluble1,000 g/L at 20°C |
| pka | -2.6(at 25℃) |
| form | Solution |
| color | brown |
| Specific Gravity | 1.48 (18/4℃) |
| Water Solubility | Miscible with water. Slightly miscible with benzene and toluene. Immiscible with paraffins. |
| λmax | λ: 240-320 nm Amax: <0.4 |
| Sensitive | Light Sensitive & Hygroscopic |
| Merck | 14,5954 |
| BRN | 1446024 |
| Stability: | Stable. Moisture sensitive. Incompatible with amines, bases, water, common metals. Releases a substantial amount of heat when diluted with water (add acid to water with care if diluting). |
| InChIKey | AFVFQIVMOAPDHO-UHFFFAOYSA-N |
| CAS DataBase Reference | 75-75-2(CAS DataBase Reference) |
| NIST Chemistry Reference | CH3SO3H(75-75-2) |
| EPA Substance Registry System | Methanesulfonic acid (75-75-2) |
Safety Information
| Hazard Codes | C |
| Risk Statements | 34-22-21/22-35 |
| Safety Statements | 26-36-45-1/2-36/37/39 |
| RIDADR | UN 3265 8/PG 2 |
| WGK Germany | 1 |
| RTECS | PB1140000 |
| TSCA | Yes |
| HazardClass | 8 |
| PackingGroup | III |
| HS Code | 29041000 |
| Hazardous Substances Data | 75-75-2(Hazardous Substances Data) |
| Toxicity | LD50 orally in Rabbit: 649 mg/kg LD50 dermal Rabbit 200 - 2000 mg/kg |
Product Application
Methanesulfonic Acid (MSA) is widely used as an efficient acid catalyst in esterification, alkylation, polymerization, and the synthesis of fine chemicals and active pharmaceutical ingredients (APIs). In the electronics industry, it serves as an important electrolyte in tin, tin-lead, and copper electroplating processes, providing excellent conductivity and supporting uniform metal deposition. MSA is also applied in industrial descaling, rust removal, and metal surface cleaning due to its strong acidity and high solubility. Additionally, it is used in oilfield acidizing treatments, battery electrolyte formulations, and as a solvent or curing accelerator in coatings and resin systems, making it a versatile chemical for various industrial and specialty applications.
