1. Chemical Structure and Properties

Active Component:

Monomethylamine (MMA)

Molecular Formula:

CH₅N

Structural Formula:

CH₃NH₂ (primary aliphatic amine).

Solvent:

Methanol (MeOH), Molecular Formula: CH₃OH.

Solution Properties:

• Concentration: 30% w/w MMA in methanol.
• Physical State: Clear, colorless liquid with a pungent ammonia-like odor.
• Boiling Point: ~64–65°C (methanol dominates volatility).
• Density: ~0.85 g/cm³ at 20°C.
• pH: Strongly alkaline (pH ~12.5 due to MMA).
• Solubility: Fully miscible with water and polar organic solvents.

2. Industrial Applications

Pharmaceutical Synthesis:

• Key reagent in antibiotic production (e.g., cephalosporins) and antidepressants (e.g., fluoxetine intermediates).

Agrochemical Manufacturing:

• Intermediate for glyphosate herbicides and neonicotinoid insecticides (e.g., imidacloprid).

Organic Chemistry:

• Alkylation Agent: Used in quaternary ammonium salt synthesis for surfactants.
• Catalyst: Accelerates esterification and transesterification reactions.

Electronics:

• Etching and cleaning agent in semiconductor fabrication (e.g., gallium nitride processing).

3. Safety and Toxicology

Hazards of MMA:

• Inhalation: Irritates respiratory tract (LC50 rat, 4h: 2,500 ppm).
• Skin Contact: Corrosive; causes burns (rabbit skin LD50: 400 mg/kg).
• Eye Exposure: Severe damage, including blindness.

Acute Toxicity:

• Chronic Effects: Potential neurotoxicity and kidney damage.

Hazards of Methanol:

• Toxicity: Metabolizes to formic acid, causing metabolic acidosis, blindness, or death (oral LD50 rat: 5,600 mg/kg).
• Flammability: Highly flammable (flash point: 11°C).

Combined Risks:

• Vapor Exposure: Simultaneous inhalation of MMA and methanol vapors amplifies respiratory and CNS effects.
• Fire Hazard: Flammable liquid with explosive vapor-air mixtures.

Protection Measures:

• PPE: Acid-resistant gloves (e.g., Viton®), chemical goggles, and NIOSH-approved respirators.
• Engineering Controls: Explosion-proof ventilation, grounded containers to prevent static sparks.

4. Environmental and Regulatory Compliance

Environmental Impact:

• MMA: Moderately toxic to aquatic life (LC50 fish: 120 mg/L; EC50 daphnia: 85 mg/L).
• Methanol: Rapidly biodegradable but toxic to aquatic organisms (LC50 fish: 1,000 mg/L).
• Atmospheric Fate: MMA reacts with hydroxyl radicals (half-life ~2 days); methanol contributes to ozone formation.

Regulatory Frameworks:

• GB 13690-2009: Classified as Class 3.2 Flammable Liquid and Class 8.2 Corrosive Substance.
• OSHA PEL: 10 ppm (MMA), 200 ppm (methanol).
• EPA CERCLA: Reportable Quantity (RQ) = 100 lbs for MMA.
• CLP Regulation: Classified as Flammable Liquid (Cat. 2), Acute Tox. 2 (H330), and Skin Corr. 1B (H314).
• REACH: Requires SDS with handling and disposal protocols.

EU:
USA:
China:

Transportation:

UN Number: UN 1230 (Methanol solution, flammable).
Hazard Class: 3 (Flammable Liquid), Packing Group II.

5. Case Studies and Application Insights

Case 1: Glyphosate Herbicide Production

Process: MMA in methanol reacts with phosphorus trichloride to synthesize methylphosphonic acid, a glyphosate precursor.

Efficiency: 30% MMA/MeOH achieves 92% yield at 70°C (Bayer’s optimized batch process).

Case 2: Semiconductor Wafer Cleaning

Application: TSMC uses MMA/MeOH solutions to remove organic residues from silicon wafers.

Advantage: Lower residue vs. pure methanol, with 20% faster processing.

Comparison with Alternatives:

• Pros: Higher solubility for non-polar reagents; faster reaction kinetics.
• Cons: Increased flammability and methanol toxicity.