Is 2-Methoxyethanol Soluble in Water?
Yes. 2-Methoxyethanol, also known as ethylene glycol monomethyl ether or methyl cellosolve, is completely miscible with water: it mixes in all proportions to give clear, homogeneous solutions that do not separate on standing. The molecule, CH3-O-CH2-CH2-OH, joins a short ether group to a terminal hydroxyl group, which gives it balanced polarity, so the same liquid also dissolves many resins, oils and organic intermediates.
Chemical and Physical Properties
The table below lists the values normally quoted on a technical data sheet for industrial-grade material.
| Parameter | Typical value |
|---|---|
| CAS number | 109-86-4 |
| Molecular formula | C3H8O2 |
| Molar mass | 76.09 g/mol |
| Appearance | Colourless liquid with a mild, ether-like odour |
| Boiling point | 124 to 125 °C at standard pressure |
| Density at 20 °C | About 0.965 g/cm³ |
| Flash point | About 39 °C closed cup |
| Water solubility | Fully miscible in all proportions |
| Solvent miscibility | Alcohols, ethers, acetone and most common organic solvents |
| Harmonised System code | 2909.44 |
| Transport classification | UN 1188, Class 3 flammable liquid |
Why Water Solubility Matters in Industry
Because the material dissolves in water as well as in organic media, formulators use it above all as a coupling solvent. In water-based paints and coatings it helps the resin dissolve evenly and the film form smoothly, and it prevents the phase separation that can occur when a solvent-borne resin first meets water. Printing inks and dye preparations use the same property to keep pigment dispersions stable and to control drying. Industrial cleaners for electronics and metal parts rely on its ability to carry both aqueous detergents and oily soil in one phase, and it is also used as a fuel de-icer additive and as a process solvent for lacquers and resins.
Safety and Regulatory Considerations
2-Methoxyethanol is classified as a reproductive toxicant in several chemical-control systems, and its use in consumer cosmetics is restricted or prohibited in many markets, so it is intended for industrial use under controlled conditions. It is also a flammable liquid whose vapour can form explosive mixtures with air, and it can be absorbed through the skin. Handling therefore requires local exhaust ventilation, closed transfer where practical, chemical-resistant gloves, eye protection and a strict ban on open flames, hot surfaces and ungrounded equipment.
Storage and Handling Guidance
Keep 2-methoxyethanol in tightly closed, clearly labelled containers in a cool, dry and well-ventilated area away from ignition sources and incompatible materials such as strong oxidisers. Bond and ground containers and equipment during transfer to prevent static discharge, keep only the amount needed for the task in the work area, and use local exhaust ventilation wherever vapour may accumulate. Read the product label and safety data sheet before use, and route waste liquid and contaminated packaging through a licensed hazardous-waste channel instead of pouring them into drains.
Frequently Asked Questions
Q: Is 2-methoxyethanol soluble in water?
Yes. It is fully miscible with water in all proportions and forms clear, homogeneous mixtures.
Q: What is the CAS number of 2-methoxyethanol?
The CAS registry number is 109-86-4 and the molecular formula is C3H8O2.
Q: What is 2-methoxyethanol used for?
As a coupling solvent in water-based coatings, printing inks and dyes, a solvent in industrial cleaners for electronics and metal parts, and a fuel de-icer additive.
Q: Is 2-methoxyethanol flammable?
Yes. It has a closed-cup flash point of about 39 °C, so it is a flammable liquid that must be kept away from ignition sources and hot surfaces.
Q: Is 2-methoxyethanol safe in cosmetics?
No. It is classified as a reproductive toxicant and is restricted or banned in cosmetics in many jurisdictions, so it is supplied for industrial use only.
Q: How should 2-methoxyethanol be stored?
In sealed, labelled containers in a cool, dry, well-ventilated area away from ignition sources and oxidisers, with bonding and grounding during transfer to prevent static discharge.