1. Chemical Structure and Properties

Molecular Formula: C₆H₁₄O₃
      Structural Formula:
      HO-CH₂CH₂-O-CH₂CH₂-O-CH₂CH₃
      A glycol ether composed of two ethylene oxide units linked to an ethyl ether group, terminated with a hydroxyl group.

Physical Properties:
     Appearance: Clear, colorless liquid with a mild, slightly sweet odor.
     Boiling Point: 202°C; Density: 0.99–1.01 g/cm³; Vapor Pressure: 0.1 mmHg at 25°C.
     Solubility: Fully miscible with water, alcohols, and most organic solvents (e.g., acetone, ethyl acetate).

Chemical Properties:
     Hydrolysis Stability: Stable under neutral conditions; hydrolyzes in strong acids/bases to ethylene glycol and ethanol.
     Thermal Stability: Decomposes above 250°C, releasing aldehydes and ethylene oxide.
     Flammability: Combustible (flash point: 85°C).

2. Industrial Applications

Coatings & Inks:
     Coalescing Agent: Enhances film formation in waterborne paints, latex adhesives, and printing inks.
     Solvent: Dissolves resins and plasticizers in industrial coatings.

Cleaning Products:
     Industrial Degreaser: Removes oils, greases, and waxes in automotive and aerospace applications.

Personal Care:
     Humectant & Stabilizer: Used in cosmetics (e.g., lotions, creams) for moisture retention and texture enhancement.

Chemical Synthesis:
     Intermediate: Produces surfactants, plasticizers, and specialty esters.

3. Safety and Toxicology

Health Hazards:
     Acute Exposure:
     Skin Contact: Mild irritation (rabbit skin LD₅₀: >2,000 mg/kg); prolonged exposure may cause defatting.
     Inhalation: Irritates respiratory tract (TLV-TWA: 10 ppm); dizziness at high concentrations.
     Ingestion: Moderately toxic (oral LD₅₀ rat: 3,500 mg/kg); metabolic acidosis in severe cases.

Chronic Effects:
     Reproductive Toxicity: Potential embryotoxicity in animal studies (EU CLP: Repr. 1B).
     Organ Toxicity: Linked to kidney damage in prolonged occupational exposure.

Protection Measures:
     PPE: Nitrile gloves, vapor respirators, and explosion-proof ventilation.
     Storage: Store in sealed containers away from oxidizers and heat sources.

4. Environmental and Regulatory Compliance

Environmental Impact:
     Biodegradability: Moderate (OECD 301F: 50–70% in 28 days).
     Aquatic Toxicity: LC₅₀ (fish, 96h): 100–200 mg/L; EC₅₀ (daphnia): 50–100 mg/L.
     Bioaccumulation: Low (log Kow: -0.5).

Regulatory Frameworks:
     EU:
     REACH: Restricted in cosmetics (Annex XVII); CLP classified as Repr. 1B (H360D).
     USA:
     EPA: Regulated under TSCA; permissible exposure limit (PEL): 10 ppm (OSHA).
     China:
     GB 13690-2009: Classified as Hazardous Chemical (Class 6.1).

Waste Management:
     Incinerate with VOC abatement; landfill disposal prohibited due to groundwater risk.

5. Case Studies and Application Insights

Case 1: Sustainable Waterborne Paints (AkzoNobel, 2023):
     Challenge: Reduce VOC emissions in architectural paints.
     Solution: Replaced 20% of ethylene glycol derivatives with diethylene glycol monoethyl ether.
     Result: Achieved 30% lower VOC emissions (ASTM D6886) while maintaining drying time (ASTM D5895).

Case 2: Green Aerospace Cleaning (Boeing, 2022):
     Process: Adopted diethylene glycol monoethyl ether in aircraft engine degreasing.
     Impact: Reduced solvent waste by 50% and met Boeing D6-17487P safety standards.

Comparative Analysis:
     DEGEE vs. EGBE:
     Pros: Lower bioaccumulation potential; better water solubility.
     Cons: Higher reproductive toxicity and regulatory restrictions.
     DEGEE vs. PGME:
     Pros: Superior solvency for polar resins; lower flammability.
     Cons: PGME offers faster evaporation and lower chronic toxicity.

Specifications:
Diethylene glycol monoethyl ether is a primary alcohol that is ethanol substituted by a 2-ethoxyethoxy group at position 2. It has a role as a protic solvent. It is a diether, a primary alcohol, a hydroxypolyether and a glycol ether. It is functionally related to a diethylene glycol.