CAS 623-53-0  ·  UN 1993  ·  C₄H₈O₃  ·  MW 104.10 g/mol

Ethyl Methyl Carbonate (EMC) — U.S. Supplier

Battery-grade and industrial-grade ethyl methyl carbonate for the U.S. market. An asymmetric linear carbonate with a -55°C melting point — the key co-solvent for low-temperature lithium-ion EV battery performance. COA, SDS, and full traceability with every order.

EMC MEC Methyl ethyl carbonate Carbonic acid ethyl methyl ester Ethyl methyl ester of carbonic acid CAS 623-53-0
623-53-0
CAS Number
104.10
Mol. Weight (g/mol)
107–109°C
Boiling Point
18°C
Flash Point (Class 3)
1.007 g/mL
Density @ 20°C
-55°C
Melting Point

Available Grades of Ethyl Methyl Carbonate

Industrial and battery-grade tiers — each ships with a lot-specific certificate of analysis.

Grade 1
Industrial / Technical Grade
Industrial solvent · Chemical intermediate · Coatings
Assay (GC)≥99.5%
Moisture (KF)≤500 ppm
Acidity≤0.01%
Color (APHA)≤10
Methanol≤0.05%
Non-volatile residue≤0.02%
Grade 2 — High Demand
Battery / Electronic Grade
Li-ion battery electrolytes · Low-temperature EV · Energy storage
Assay (GC)≥99.99% (4N)
Moisture (KF)≤30 ppm
Acidity≤10 ppm
Total metals≤1 ppm each
Methanol≤0.002%
Non-volatile residue≤5 ppm

Physical & Chemical Properties

Identification
Chemical NameEthyl Methyl Carbonate
AbbreviationEMC (also MEC)
CAS Number623-53-0
Molecular FormulaC₄H₈O₃
Molecular Weight104.10 g/mol
EINECS Number210-939-5
UN NumberUN 1993
Transport ClassClass 3, Packing Group II
TSCA StatusListed on TSCA inventory
Physical Properties
AppearanceColorless clear liquid
Boiling Point107–109°C (225–228°F)
Melting Point-55°C (-67°F)
Flash Point18°C (64°F, closed cup)
Density @ 20°C1.007–1.013 g/mL
Viscosity @ 25°C0.65 mPa·s
Refractive Index (n20/D)1.3772
Vapor Pressure @ 20°C~18 hPa
Water Solubility~13% (partially miscible)
OdorMild, slightly fruity

What Is Ethyl Methyl Carbonate Used For?

EMC's combination of very low melting point, low viscosity, and intermediate boiling point makes it a uniquely effective co-solvent for wide-temperature-range lithium-ion battery electrolytes.

Lithium-Ion Battery Electrolytes — Low-Temperature Performance

Ethyl methyl carbonate is a critical co-solvent in lithium-ion battery electrolyte formulations, particularly for applications requiring reliable performance at low temperatures. Its melting point of -55°C (-67°F) — the lowest of the common carbonate solvents — keeps electrolyte solutions liquid and ionically conductive in cold environments where DMC-heavy formulations might lose performance. EV batteries must deliver usable range and peak power down to -20°C or below for cold-climate operation; EMC is a primary tool for meeting these temperature requirements. Standard battery electrolyte formulations include EC/DMC/EMC or EC/EMC blends with LiPF₆, balanced to optimize ionic conductivity, viscosity, electrochemical stability, and temperature range. Battery-grade EMC (≥99.99%, moisture ≤30 ppm, metals ≤1 ppm) is required to protect LiPF₆ stability and cell cycle life.

Asymmetric Carbonate — Unique Solvation Properties

Unlike symmetric linear carbonates (DMC has two methyl groups; DEC has two ethyl groups), EMC is an asymmetric carbonate with one methyl and one ethyl ester group. This asymmetry gives EMC intermediate and partially distinct solvation characteristics compared to DMC and DEC. In electrolyte blend design, EMC provides a different solvation shell geometry around Li⁺ ions, which can affect ion-pairing behavior, SEI chemistry, and electrode compatibility. The combination of EC + EMC has become a preferred baseline electrolyte system in many high-performance Li-ion applications precisely because of EMC's balanced property profile — low viscosity, low melting point, and moderate boiling point.

Energy Storage & Grid Stationary Applications

Beyond EV applications, EMC is used in lithium-ion battery packs for grid-scale energy storage systems (ESS) where wide operating temperature ranges are required. Utility-scale storage facilities may face ambient temperatures from -20°C to +50°C across seasons; EMC-based electrolytes maintain performance across this range better than formulations relying solely on DMC or DEC.

Industrial Solvent Applications

In industrial-grade form, EMC functions as a solvent with properties intermediate between DMC and DEC — moderate evaporation rate, good resin solvency, and low toxicity profile. Applications include coatings, adhesives, and as a chemical intermediate in carbonate ester synthesis. Its low flash point (18°C) requires proper flammable-liquid handling procedures, but its low toxicity and absence of carcinogenic or reproductive toxicity classifications make it operationally favorable over legacy halogenated solvents.

Key differentiator — melting point -55°C: No other common carbonate solvent remains fully liquid at -55°C. This property makes EMC a non-negotiable component in electrolyte formulations targeting EV performance in cold climates. As cold-weather EV range becomes a critical consumer specification, demand for battery-grade EMC continues to grow alongside overall lithium-ion battery production volume.

EMC Packaging Options

From R&D samples to bulk quantities. Contact us for pricing, MOQ, and lead times.

🧪
Sample / R&D
Evaluation quantities
🪣
5-Gallon Pail
~19 liters
🛢️
55-Gallon Drum
208 L steel drum
📦
IBC / Tote
275–330 gallon
🚛
Bulk Tanker
TL / LTL quantities

Documents Available for EMC

All documentation available on request via the quote form below.

📄
Safety Data Sheet (SDS)
GHS-formatted · UN 1993 · Class 3 PG II
📋
Certificate of Analysis (COA)
Lot-specific · All QC parameters
📊
Technical Data Sheet (TDS)
Physical and chemical properties
TSCA Compliance
CAS 623-53-0 on TSCA inventory

Regulatory Status

TSCA ListedCAS 623-53-0 on TSCA inventory
GHS Class 3 CompliantUN 1993 · Flammable liquid PG II
Not a CMR CompoundNo carcinogen/mutagen/reprotoxic classification
U.S. Import CompliantFull chain-of-custody documentation

Frequently Asked Questions — Ethyl Methyl Carbonate

What is ethyl methyl carbonate (EMC)?

Ethyl methyl carbonate (CAS 623-53-0) is a colorless flammable asymmetric linear carbonate with formula C₄H₈O₃ and MW 104.10 g/mol. It has a melting point of -55°C, boiling point of 107–109°C, and flash point of 18°C. EMC is a critical co-solvent in lithium-ion battery electrolytes, valued for its low-temperature performance. It is also known as methyl ethyl carbonate (MEC).

Why is EMC critical for cold-weather EV performance?

EMC's -55°C melting point is the lowest of all common carbonate solvents, keeping electrolyte formulations liquid and conductive at sub-zero temperatures. EV batteries must deliver acceptable range and power at -20°C or below — EMC-based electrolytes maintain ionic conductivity at temperatures where DMC-only formulations underperform. This makes EMC a key component in electrolyte design for cold-climate EV applications.

Is EMC the same as MEC?

Yes. Ethyl methyl carbonate (EMC) and methyl ethyl carbonate (MEC) are different names for the same compound: CAS 623-53-0, C₄H₈O₃. EMC is the more common abbreviation in battery industry literature.

What is the difference between EMC and DMC?

DMC (dimethyl carbonate) is a symmetric carbonate with two methyl groups, lower boiling point (90.6°C), and melting point of 2–4°C. EMC (ethyl methyl carbonate) is asymmetric (one methyl + one ethyl group), boiling point 107–109°C, and melting point -55°C. EMC's lower freezing point makes it superior for cold-temperature electrolyte applications; DMC offers lower viscosity and faster evaporation for coating applications.

What purity is required for battery-grade EMC?

Battery-grade EMC requires: assay ≥99.99% (4N, GC), moisture ≤30 ppm (Karl Fischer), acidity ≤10 ppm, total metals ≤1 ppm each, methanol ≤0.002%. These specifications protect LiPF₆ stability and prevent electrolyte decomposition reactions that degrade cell capacity and cycle life.

What are the transport requirements for EMC?

EMC is classified as UN 1993 (Flammable liquid, n.o.s.), Hazard Class 3, Packing Group II. Flash point is 18°C (64°F). Shipments require flammable-liquid compliant packaging, proper placarding, and shipping documentation. CARMELSOLV™ ships throughout the continental United States.

Is EMC TSCA listed?

Yes. CAS 623-53-0 is listed on the U.S. EPA TSCA Chemical Substance Inventory and is fully compliant for commercial import and distribution in the United States.

Request a Quote — Ethyl Methyl Carbonate

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