1. Chemical Structure and Properties

Molecular Formula:

C₂H₇NO

Structural Formula:

HOCH₂CH₂NH₂ – A primary amine with both hydroxyl (-OH) and amino (-NH₂) functional groups.

Physical Properties:

• Appearance: Colorless to pale yellow viscous liquid with an ammonia-like odor.
• Boiling Point: 170°C
• Density: 1.01 g/cm³
• Viscosity: 24 mPa·s at 20°C
• Solubility: Fully miscible with water, ethanol, and polar solvents; hygroscopic.

Chemical Properties:

• Basicity: Weak base (pKa = 9.5), reacts with acids to form salts (e.g., MEA hydrochloride).
• Reactivity: Undergoes esterification, alkylation, and chelation; thermally stable up to 140°C.

2. Industrial Applications

Gas Treatment:

• Acid Gas Removal: Widely used in amine scrubbing to capture CO₂ and H₂S from natural gas and flue gas (e.g., Shell’s ADIP-X process).
• Efficiency: Achieves 90% CO₂ capture at 40–60°C with 30% MEA solution.

Personal Care:

• Surfactant Synthesis: Intermediate for cocamide MEA and lauramide MEA in shampoos and lotions.

Agrochemicals:

• Herbicide Production: Key component in glyphosate formulations (e.g., Monsanto’s Roundup®).

Pharmaceuticals:

• Drug Intermediate: Used in synthesizing antihistamines (e.g., diphenhydramine).

Textiles:

• pH Adjuster: Neutralizes acidic dyes in wool and silk processing.

3. Safety and Toxicology

Health Hazards:

• Skin/Eye Contact: Severe irritation and burns (rabbit skin LD50: 2,000 mg/kg).
• Inhalation (≥10 ppm): Respiratory tract irritation, pulmonary edema (LC50 rat, 4h: 2,000 ppm).
• Ingestion: Moderately toxic (oral LD50 rat: 2,000 mg/kg); causes gastrointestinal damage.

Acute Exposure:

• Chronic Effects: Potential liver/kidney toxicity and sensitization (allergic dermatitis).

Flammability:

• Combustible liquid (flash point: 93°C; autoignition temperature: 410°C).

Protection Measures:

• PPE: Nitrile gloves, goggles, and respirators for vapor control.
• First Aid: Flush affected areas with water for 15+ minutes; seek medical attention.

4. Environmental and Regulatory Compliance

Environmental Impact:

• Aquatic Toxicity: LC50 (fish, 96h): 1,000 mg/L; EC50 (daphnia): 800 mg/L.
• Biodegradability: Readily biodegradable (OECD 301B: >90% in 28 days).
• Atmospheric Fate: Reacts with hydroxyl radicals (half-life ~1 day).

Regulatory Frameworks:

• EU: CLP Regulation: Skin Corr. 1B (H314), Eye Dam. 1 (H318).
• USA: OSHA PEL: 3 ppm (8-hour TWA); EPA TRI reporting required.
• China: GB 13690-2009: Classified as Class 8.2 Corrosive Substance.

Transport:

UN Number: UN 2491; Hazard Class: 8 (Corrosive), Packing Group III.

5. Case Studies and Application Insights

Case 1: CO₂ Capture in Power Plants

Process: MEA-based scrubbing at Boundary Dam Power Station (Canada) captures 1 million tons of CO₂ annually.

Challenges: High energy demand for solvent regeneration (3–4 GJ/ton CO₂).

Case 2: Personal Care Formulations

Application: L’Oréal uses cocamide MEA in Garnier Fructis® shampoos for foam stabilization.

Performance: Enhances lather density by 30% vs. sulfate-free alternatives.

Comparative Analysis:

• Pros: MEA has higher CO₂ absorption capacity (0.5 mol CO₂/mol amine vs. 0.3 for DEA).
• Cons: MEA degrades faster under oxidative conditions, requiring frequent solvent replacement.