1. Chemical Structure and Properties
Molecular Formula: C₄H₈O₂
Structural Formula:
CH₃COOCH₂CH₃
A simple ester formed by the reaction of acetic acid and ethanol.
Physical Properties:
Appearance: Clear, colorless liquid with a fruity, sweet odor.
Boiling Point: 77°C; Density: 0.90 g/cm³; Vapor Pressure: 73 mmHg at 20°C.
Solubility: Miscible with most organic solvents (e.g., ethanol, ether); slightly soluble in water (3% w/w at 20°C).
Chemical Properties:
Hydrolysis: Reacts with water under acidic or alkaline conditions to regenerate acetic acid and ethanol.
Flammability: Highly flammable (flash point: -4°C; autoignition temperature: 427°C).
Polarity: Moderately polar (log P: 0.7), balancing solvency for both polar and non-polar compounds.
2. Industrial Applications
Paints & Coatings:
Universal Solvent: Key component in nitrocellulose lacquers, acrylics, and epoxy resin formulations for fast drying and low toxicity.
Pharmaceuticals:
Extraction Medium: Isolates APIs (e.g., penicillin) and serves as a reaction solvent in tablet coating.
Food & Fragrance:
Flavoring Agent: Used in artificial fruit flavors (e.g., pear, pineapple) and perfumes due to its pleasant odor.
Electronics:
Cleaning Agent: Removes flux residues from printed circuit boards (PCBs) without damaging components.
3. Safety and Toxicology
Health Hazards:
Acute Exposure:
Inhalation (≥400 ppm): Dizziness, respiratory irritation (TLV-TWA: 400 ppm).
Skin Contact: Mild irritation; prolonged exposure causes defatting and dermatitis.
Ingestion: Low toxicity (oral LD₅₀ rat: 5,600 mg/kg).
Chronic Effects:
Neurotoxicity: Limited evidence of CNS effects; not classified as a carcinogen (IARC Group 3).
Protection Measures:
PPE: Nitrile gloves, vapor respirators, and adequate ventilation.
Storage: Fireproof containers in cool, well-ventilated areas away from ignition sources.
4. Environmental and Regulatory Compliance
Environmental Impact:
Biodegradability: Rapid aerobic degradation (OECD 301F: >90% in 28 days).
VOC Emissions: Classified as a volatile organic compound (VOC) under EPA regulations; contributes to ozone formation.
Regulatory Frameworks:
EU:
CLP Regulation: Labeled Flammable Liquid (Category 2), Eye Irrit. 2 (H319).
REACH: Registered with no current restrictions.
USA:
OSHA PEL: 400 ppm (8-hour TWA); EPA: VOC limits enforced under Clean Air Act.
China:
GB 13690-2009: Classified as Hazardous Chemical (Class 3.2).
Waste Management:
Incineration with energy recovery; wastewater treatment via activated sludge.
5. Case Studies and Application Insights
Case 1: Eco-Friendly Coatings (Sherwin-Williams, 2022):
Application: Replaced toluene with ethyl acetate in waterborne wood coatings.
Result: Achieved 30% lower VOC emissions while maintaining drying speed and gloss.
Case 2: Pharmaceutical Tablet Coating (Pfizer, 2021):
Process: Used ethyl acetate as a solvent for enteric coatings on acid-sensitive APIs.
Efficiency: Reduced solvent recovery costs by 20% compared to acetone-based systems.
Comparative Analysis:
Ethyl Acetate vs. Acetone:
Pros: Lower toxicity, pleasant odor, and slower evaporation rate.
Cons: Higher cost and flammability risk compared to acetone.