Structure, Solubility & Key Technical Notes EGMEA structure (condensed formula): CH₃OCH₂CH₂OOCCH₃ - the methoxyethyl ether chain (–OCH₂CH₂OCH₃) provides H-bond acceptor character and polar solubility, while the acetate group (–OOCCH₃) contributes ester solvency and a mild, pleasant odor.  |  Why does EGMEA have higher density than similar esters? The two oxygen-containing functional groups (ether + ester) both contribute electron-withdrawing character that tightens molecular packing, raising density to 1.005–1.010 g/cm³ - notable for a five-carbon solvent where most simple esters (ethyl acetate, butyl acetate) have densities below 0.9 g/cm³.  |  Acidity specification significance: The ≤0.1% acidity limit controls residual acetic acid from incomplete esterification or hydrolysis - critical in photoresist applications (trace acid disrupts base-catalyzed development chemistry) and in NC lacquers (acid attacks pigment dispersants, causing viscosity drift).  |  Water miscibility: EGMEA is partially miscible with water; fully miscible with most organic solvents including alcohols, ketones, aromatic hydrocarbons, and other glycol ether solvents.

Specification Item	Standard / Value	Test Method / Significance
Appearance	Colorless transparent liquid	Visual inspection; no haze, precipitate, or color
Purity (GC)	≥ 99.0%	GC area normalization; every batch
Water Content	≤ 0.1%	Karl Fischer titration; affects hydrolysis stability
Acidity (as AcOH)	≤ 0.1%	Potentiometric titration; critical for photoresist & NC
Density (d20)	1.005–1.010 g/cm³	Digital density meter
Boiling Point	143.0–145.0 °C	(1013 hPa); GC head-space confirmation
Flash Point	~49 °C (closed cup)	Class 3 Flammable Liquid; UN 3271, PG III for transport
Refractive Index	1.399–1.403 (n20/D)	Refractometer; identity and purity confirmation
Color (Pt-Co)	≤ 10	Colorimeter; critical for clear coating and electronics
Packaging	200 kg iron drum  /  1000 kg IBC tank	DG Class 3 export packaging; UN-approved containers

The most established application of EGMEA is as a primary high-solvency solvent in nitrocellulose (NC) lacquer systems. Nitrocellulose's complex hydrogen-bonding network demands solvents with a specific solubility parameter window - EGMEA's combined ether-ester functionality places it squarely in the optimal range for dissolving NC at high concentrations, outperforming simple ketone or aromatic solvents of similar boiling point.

In NC furniture lacquers and automotive refinish primers, EGMEA controls the critical drying rate: its boiling point of 143–145°C is substantially higher than ethyl acetate (77°C) or MEK (80°C), extending the flow-and-leveling window after spray application so the wet film self-levels and releases trapped air before surface gelation - delivering smoother, higher-gloss surfaces with fewer visible application defects on complex furniture profiles.

In markets outside the EU - particularly Asia, the Middle East, and Latin America - where NC coatings remain the dominant technology for furniture, leather, and aircraft finishing, EGMEA continues to be widely used under locally applicable occupational and environmental regulations. Sinolook supplies to these markets with full local-regulation documentation support.

EGMEA has an established track record as a casting solvent for novolak-based positive photoresists used in i-line (365 nm) and g-line (436 nm) semiconductor lithography. It dissolves both the novolak resin binder and diazonaphthoquinone (DNQ) photoactive compound in a homogeneous solution for spin-coating at precise, uniform film thicknesses on silicon wafers.

For advanced node manufacturing (below 130 nm) using deep UV (248 nm KrF / 193 nm ArF) or EUV lithography with chemically amplified resists (CARs), PGMEA has displaced EGMEA as the industry standard photoresist solvent, owing to PGMEA's absence of Repr. 1B classification and superior CAR polymer compatibility. However, for legacy device manufacturing, photomask production, MEMS applications, and specialty optical coatings using older process nodes, EGMEA's long-established process compatibility remains an asset in controlled environments.

In the printing ink industry, EGMEA's combination of strong solvency for polyurethane, vinyl, and acrylic ink binder systems and its slower evaporation rate make it a technically effective retarder and co-solvent. In gravure inks for paper, film, and foil substrates, adding EGMEA prevents premature solvent flash-off in the ink train, maintaining viscosity consistency across the print run and reducing plate-out. In screen printing inks, it prevents mesh-blocking during production stoppages.

The strictly controlled acidity specification (≤0.1% as acetic acid) is particularly valuable in ink formulations using base-sensitive pigments: excess acidity can shift pH in the ink vehicle, causing pigment flocculation, viscosity drift, and color shift in aged inks - especially in inks with tight rheological specifications. EGMEA's low acidity ensures formulation stability over production and storage time.

EGMEA's high solvency for rosin-based and no-clean flux residues, combined with its compatibility with common PCB substrate materials (FR4, polyimide), makes it an effective precision cleaning solvent for PCB assemblies and semiconductor packaging. Its lower evaporation rate vs IPA or acetone allows longer dwell time on complex surface geometries, improving flux residue removal efficiency. For optical component cleaning, the low color (≤10 Pt-Co) and low acidity specifications ensure no surface staining or corrosion of coated optical surfaces.

In industrial adhesives - contact cements, pressure-sensitive adhesive coatings, and reactive polyurethane systems - EGMEA serves as a high-solvency co-solvent that controls application viscosity, improves substrate wetting on non-porous surfaces (metal, glass, dense plastic), and provides an extended open-time window for assembly operations where parts must be positioned before bonding under press or nip.

As an organic synthesis solvent, EGMEA's relatively high boiling point for a five-carbon ester, good thermal stability, and compatibility with a wide range of nucleophiles and catalytic systems make it useful as a reaction medium in pharmaceutical API synthesis, agrochemical manufacturing, and specialty fine chemical processes requiring an ester-based polar solvent at elevated temperature reflux conditions.

Property	EGMEA CAS 110-49-6	EGEA CAS 111-15-9	PGMEA (PMA) CAS 108-65-6
Full Name	EG Monomethyl Ether Ac.	EG Monoethyl Ether Ac.	Propylene Glycol ME Ac.
Mol. Formula	C₅H₁₀O₃	C₆H₁₂O₃	C₆H₁₂O₃
Mol. Weight (g/mol)	118.13	132.16	132.16
Boiling Point (°C)	143–145	156–157	146–148
Flash Point (°C)	~49	~56	~47
Density (g/cm³)	1.005–1.010	0.974–0.978	0.964–0.968
EU CLP Repr. Class.	Repr. 1B ⚠	Repr. 1B ⚠	Not classified ✓
US HAP Status	Not listed	Not listed	Not listed
Semiconductor Use	Legacy / i-line & g-line	Limited	Primary modern standard ✓
Key Market / Use	NC coatings, legacy electronics, inks (Asia/ME/LatAm)	Coatings, printing inks (transitioning)	Advanced semicon., modern coatings, electronics (global)

Recommendation: For new product development and reformulation in EU markets or any application where Repr. 1B classification is a concern, PGMEA is the preferred regulatory choice - it delivers a comparable boiling point (~147°C), similar evaporation profile, excellent resin solvency, and no Repr. 1B classification. Sinolook supplies PGMEA and provides comparative technical data and formulation transition support. Request EGMEA→PGMEA transition package →

Sinolook documentation commitment: Every EGMEA shipment includes EU CLP-compliant SDS (with full Repr. 1B hazard elements), REACH compliance letter, Annex XVII restriction status confirmation, TSCA inventory confirmation, and DG transport documentation (UN 3271, Class 3, PG III). Application-specific regulatory guidance and PGMEA substitution technical support available on request.

⚠️ REPRODUCTIVE HAZARD: EGMEA is classified Repr. 1B (H360D). Pregnant workers and workers planning pregnancy must not be exposed to EGMEA. Skin and inhalation absorption both contribute to systemic exposure - chemical-resistant gloves (nitrile or butyl rubber) and local exhaust ventilation are mandatory, not optional, in occupational handling.

Q: Why is EGMEA classified as Repr. 1B, and what does this mean in practice?

EGMEA is classified as a reproductive toxicant (Repr. 1B, H360D) under EU CLP because it is metabolically converted - via alcohol dehydrogenase and aldehyde dehydrogenase - to methoxyacetic acid, the ultimate toxic species responsible for testicular atrophy and fetal developmental toxicity observed in animal studies with EGME and its esters. Repr. 1B means "presumed to cause developmental effects in humans based on substantial animal evidence." In practice: (1) EU products containing EGMEA above cut-off concentrations require Repr. 1B hazard labeling; (2) EGMEA is restricted in consumer product concentration under REACH Annex XVII Entry 70; (3) employers must implement stringent occupational exposure controls, including exclusion of pregnant workers. Full details at ECHA's substance page for CAS 110-49-6.

Q: What is the recommended regulatory substitute for EGMEA?

PGMEA (Propylene Glycol Monomethyl Ether Acetate, CAS 108-65-6) is the most widely adopted regulatory substitute for EGMEA across coatings, semiconductor photoresists, printing inks, and electronics cleaning. PGMEA offers a comparable boiling point (~147°C), similar evaporation profile, excellent solvency for modern polymer binder systems, full compatibility with chemically amplified photoresist formulations, and - critically - no Repr. 1B classification under EU CLP. Sinolook supplies PGMEA and provides technical data packages, qualification samples (0.5–5 kg), and formulation transition guidance for customers moving from EGMEA to PGMEA. Contact our technical team for transition support.

Q: Why does the acidity specification matter - and what causes EGMEA to become acidic?

Acidity (≤0.1% as acetic acid) controls residual acetic acid from incomplete esterification during production, or from hydrolysis during storage (EGMEA + H₂O → EGME + AcOH, catalyzed by moisture and trace acid/base). Excess acidity causes: (1) in NC lacquers - attacks pigment dispersants and resin modifiers, causing viscosity drift and color change in aged formulations; (2) in photoresist applications - trace acid interferes with base-catalyzed development chemistry, causing CD uniformity failures at advanced nodes; (3) in adhesives - corrodes metal substrates, affecting bond strength. Sinolook monitors acidity on every production batch and recommends retesting any EGMEA stock held longer than 6 months before critical use.

Q: Is EGMEA permitted for industrial use in the EU despite its Repr. 1B classification?

Yes - EGMEA may be used in industrial and professional occupational settings in the EU where exposure is controlled through engineering measures (local exhaust ventilation), occupational exposure limits (OELs), and appropriate PPE, in compliance with applicable national legislation implementing EU Directive 98/24/EC on chemical agents at work. The REACH Annex XVII Entry 70 restriction applies to consumer products - products intended for the general public - above specified concentration limits, not to professional industrial use. For exact OEL data, consult the GESTIS substance database (entry for CAS 110-49-6) and applicable national authority guidance.

Q: What is EGMEA's UN number and transport classification for international shipping?

EGMEA is classified as a Class 3 Flammable Liquid for international transport with flash point ~49°C. Transport details: UN 3271 (Ethers, n.o.s.) or UN 1289 (depending on classification authority), Hazard Class 3, Packing Group III, proper shipping name "Ethers, n.o.s. (2-methoxyethyl acetate)." Sinolook prepares full DG export documentation for all shipments from Chinese ports (Shanghai, Tianjin, Qingdao, Guangzhou, Ningbo) including DG declaration, CLP-compliant SDS, and IMDG-compliant packing certificate. Incoterms available: EXW, FOB, CFR, CIF, DAP, DDP. Standard lead time 7–14 business days; expedited processing available.

Related products & regulatory substitutes: PGMEA (Propylene Glycol Monomethyl Ether Acetate)  ·  EGEA (Ethylene Glycol Monoethyl Ether Acetate)  ·  EGME (Ethylene Glycol Monomethyl Ether)  ·  Propylene Glycol Monoethyl Ether Acetate  ·  Butyl Cellosolve Acetate  ·  Diethylene Glycol Monomethyl Ether