Can GLDA.Na4 be added to shampoo?

Yes, GLDA·Na₄ (Tetrasodium Glutamate Diacetate) can be safely added to shampoo formulations, offering eco-friendly chelation and multiple functional benefits. Here’s why and how to use it effectively:

1. Benefits in Shampoo

Hard Water Protection:

Chelates Ca²⁺/Mg²⁺ ions (up to 250 mg CaCO₃/g), preventing metal-induced dullness and improving lather stability in hard water.

Gentle Scalp Care:

Biodegradable and non-irritating (unlike EDTA), suitable for sensitive scalps.

Preservative Boost:

Binds metal ions that promote microbial growth, extending shelf life without harsh preservatives.

Hair Color Protection:

Reduces metal-catalyzed oxidation, helping maintain vibrant color-treated hair.

2. Recommended Usage

Dosage: 0.1–0.5% (typically replaces EDTA or citrates).

pH Compatibility: Stable in shampoo pH range (4.5–7.0).

Synergistic Pairings:

With cocamidopropyl betaine (enhances foam stability).

With natural preservatives (e.g., benzyl alcohol + salicylic acid).

3. Safety & Regulations

Biodegradability: >90% (OECD 301B), compliant with EU Ecolabel and COSMOS Organic.

Non-Toxic: Rinse-off product risk is negligible (no skin accumulation).

4. How to Formulate

Example Shampoo Recipe (with GLDA·Na₄):

text

- Water (to 100%)

- Sodium Lauryl Sulfate (SLS) / SLES (10–15%)

- Cocamidopropyl Betaine (3–5%)

- GLDA·Na₄ (0.3%)

- Panthenol (0.5%)

- Fragrance & Preservative (q.s.)

- Citric Acid (adjust pH to 5.5)

5. Comparison to Alternatives

Chelator GLDA·Na₄ EDTA Citric Acid

Eco-Friendliness High (readily biodegradable) Low (persistent) High

Hard Water Performance Excellent Excellent Weak

pH Stability 2–12 2–12 2–8

Scalp Safety Non-irritating May irritate Safe

Conclusion:

GLDA·Na₄ is an ideal EDTA alternative for shampoos, combining performance, sustainability, and mildness. Perfect for "clean beauty" or hard-water-focused formulations.