MGDA 3A 40: A Versatile Chelating Agent for Modern Industry

What is MGDA 3A 40?

MGDA 3A 40 refers to a 40% aqueous solution of Methylglycine N,N-diacetic acid (MGDA) in its trisodium salt form. Also known as Trisodium MGDA or Trisodium salt of methylglycine diacetic acid, it is a powerful, biodegradable chelating agent. MGDA is part of a new generation of environmentally friendly chelators, designed to replace older compounds like EDTA, NTA, and phosphates in various formulations.

The « 3A » typically refers to methylglycine diacetic acid, where “3A” alludes to its three acetic acid groups, and “40” indicates a 40% concentration in water.

Chemical Properties

• Chemical formula (trisodium salt): C₇H₇NO₆Na₃

• Molar mass: ~271.1 g/mol (trisodium salt)

• Appearance: Clear to slightly yellow liquid (in solution form)

• Solubility: Fully water-soluble

• pH (of 40% solution): Typically 10–11

Applications of MGDA 3A 40

Due to its strong chelating power and excellent biodegradability, MGDA 3A 40 finds uses across various industries:

1. Detergents and Cleaners

• Used in automatic dishwashing detergents (ADW) and laundry detergents.

• Prevents scale and soap scum by binding calcium and magnesium ions.

• Enhances cleaning efficiency, especially in hard water.

2. Cosmetics and Personal Care

• Acts as a stabilizer and improves the performance of active ingredients.

• Common in shampoos, cleansers, and skin care products.

3. Industrial Cleaning

• Ideal for metal cleaning, bottle washing, and surface cleaning applications.

• Functions as a sequestering agent to improve the effectiveness of alkaline cleaners.

4. Water Treatment

• Used in boiler water, cooling towers, and reverse osmosis systems to control scaling and corrosion.

5. Textile and Paper Industry

• Serves as a complexing agent in bleaching, dyeing, and finishing processes.

6. Agriculture

• Helps chelate micronutrients (like iron, zinc, manganese), improving their bioavailability in fertilizers.

Benefits of MGDA 3A 40

• Eco-friendly: Rapidly biodegradable under OECD 301 guidelines (>60% in 28 days).

• Highly effective: Comparable or superior to EDTA and NTA in binding metal ions like Ca²⁺, Mg²⁺, Fe³⁺.

• Safe profile: Low toxicity and not classified as a carcinogen or mutagen.

• Stable across pH range: Works in both acidic and alkaline environments.

• Compatible with many formulations: Doesn’t interfere with surfactants or enzymes.

How is MGDA 3A 40 Made?

1. Starting Material: Methylglycine (also known as sarcosine): Sarcosine is a naturally occurring amino acid derivative.

2. Reaction with Chloroacetic Acid: Sarcosine is reacted with chloroacetic acid in the presence of a base. This step introduces the acetic acid groups needed for chelation.

3. Neutralization: The resulting acid form (MGDA) is neutralized with sodium hydroxide to form the trisodium salt.

4. Dilution: Finally, the trisodium MGDA is diluted with water to achieve a 40% concentration, creating the MGDA 3A 40 solution.

This process is designed to be clean and efficient, with a focus on minimizing byproducts and environmental impact.