Methacrylic acid (MAA) plays an active role in industries such as materials science, chemicals, textiles, and wastewater treatment. It’s an important industrial raw material—but also a corrosive acid that can pose risks to health and property if not handled or transported properly. This guide will help you understand its applications, dangers, and how to store it safely.

 

1. What is Methacrylic Acid (MAA)? Hazard Classification & Main Applications

Methacrylic Acid (MAA), HS Code: 2916 1310 002, is a colorless, transparent organic compound in liquid form with the chemical formula C₄​H₆O₂. It’s classified under UN No. 2531, Class 8 Corrosive Substances.

 

Physical Properties :

• Melting Point: 15–16°C (pure substance)
• Boiling Point: 161°C (standard pressure)
• Density: 1.015 g/cm³ (at 20°C)
• Solubility: Soluble in water, alcohols, ketones, esters, and other polar organic solvents
• Vapor Pressure: 0.67 kPa (at 20°C)
• Acidity (pKa): 4.66 (at 25°C) – classified as a weak acid

Chemical Properties :

• Carboxylic Acid Functionality: Reacts with bases to form methacrylate salts
• Double Bond Reactivity: Undergoes free radical polymerization to form PMA
• Volatility: Decomposes at high temperatures and releases irritating vapors

MAA has a pungent odor, forms explosive mixtures with air, and is moderately toxic—irritating to skin and mucous membranes. While it’s not classified as carcinogenic, proper handling is critical. Primary Applications of MAA :

(1) Polymer Monomer

MAA is used to synthesize Polymethacrylic acid (PMAA) via polymerization. PMAA is widely applied as a softener and coating in textile and leather industries due to its excellent stability and processability.

(2) Chemical Derivatives

MAA can be used to produce a wide range of derivatives including:

• Methyl Methacrylate (MMA)
• Methacrylic anhydride
• Methacryloyl chloride
• Methacrylamide
• Methacrolein
• Adhesives, synthetic rubber, etc.

Its high reactivity and versatility make it a key player in industrial manufacturing.

 

Further Reading : What is MMA? Hazard Classification & Uses

 

(3) Ion-Exchange Resins

MAA can be copolymerized with divinylbenzene to produce ion-exchange resins used in water purification, capable of adsorbing cations like Na⁺, K⁺, Mg²⁺, and Ca²⁺—essential in wastewater treatment.

 

2. What Kind of Chemical is MAA? Understanding Its Hazards

When exposed to reactive substances, MAA may cause exothermic reactions and splashing, releasing harmful vapors and gases. It is moderately toxic and can cause irritation to the eyes, skin, and respiratory system. Immediate medical attention is required upon exposure.

Potential Hazards:

• Skin contact : Causes irritation or burns
• Ingestion : Leads to gastrointestinal discomfort, vomiting, dizziness, drowsiness
• Eye contact : Causes burns

 

3. How to Store MAA Properly: Key Safety Precautions

(1) Store in a Cool, Well-Ventilated Place

Keep MAA in a shaded, ventilated area. Maintain temperature above its melting point (16°C) but below 55°C (Self-Accelerating Polymerization Temperature, SAPT). Avoid direct sunlight. MAA can react violently with oxidizers, peroxides, nitrates, acids, alkalis, halogens, azides, metals, ketones, ethers, etc.—store separately to reduce risk.

 

(2) Seal Packaging

MAA is highly prone to polymerization when exposed to air—especially in the absence of polymerization inhibitors. This reaction can lead to a rapid buildup of pressure inside the container, significantly increasing the risk of explosion. Additionally, as a volatile liquid, MAA can easily evaporate and disperse into the air, posing serious health risks if inhaled. To ensure safe storage and handling, MAA should always be packaged with an appropriate stabilizer and sealed airtight to prevent both unwanted reactions and vapor leakage.

(3) Label as Hazardous Material

Label MAA containers clearly to inform handlers of its properties and emergency procedures. In case of an incident during transport, hazard labels help responders act quickly and correctly.

 

Further Reading : What are Dangerous Goods? A Quick Guide to Hazard Classification and Transport Regulations

 

(4) Wear Protective Gear

Operators must wear corrosion-resistant gloves, protective clothing, and gas masks. Proper training is essential due to the chemical’s corrosive nature.

(5) Avoid Spark-Producing Tools

MAA can explode upon contact with flames, heat, or static electricity. Use plastic tools instead of metal ones and ensure no fire sources are present in the environment.

(6) Install Emergency Equipment

Equip storage areas with emergency handling systems. Place MSDS (Material Safety Data Sheet) and emergency instructions in accessible, visible locations for quick response during accidents.

 

Further Reading : How to Understand the MSDS (Material Safety Data Sheet) and Key Details to Watch For

 

Published Date : January 3, 2025