GLDA (47 % liquid)
Binds hard-water minerals, for less soap scum.
Opens the calculator’s starter recipe, 1000 g of oils, with this additive at the dose it fills in, ready to change.
What it is
GLDA, tetrasodium glutamate diacetate, is a chelating agent sold as a liquid with at least 47.4 % of it dissolved in water. Its maker says it is very stable in alkali and allowed in soaps under the COSMOS standard.
Nouryon primary source, Nourish Us Naturals supplier or guide
How much
- 0.25–0.5 % of the batch, range 0.1–1 in cosmetics generally filled in Nourish Us Naturals supplier or guide
- up to 0.28 % of the batch in rinse-off products, the highest reported use: not a recommendation CIR primary source
The calculator fills in 0.25 % of the batch: 3.6 g for the 1000 g of oils in its starter recipe.
When and how
- Usually: in the water, before the lye.
- Also used: into the lye solution, into the oils.
Nouryon primary source
What it does to the recipe
- 52 % is water, taken off the recipe’s water.
Nouryon primary source
Worth knowing
- COSMOS, the organic and natural cosmetics standard, allows it in soap. Nouryon primary source
- No soap source gives a dose: the one here is for cosmetics in general.
Spoons and drops
- 1 tsp ≈ 6.9 g
- 1 tbsp ≈ 20.7 g
- 1 cup ≈ 331 g
Nouryon primary source
INCI name
Tetrasodium Glutamate Diacetate
- CAS number
- 51981-21-6
- EC number
- 257-573-7
- As weighed
- Tetrasodium Glutamate Diacetate 47.4 %, Aqua 52.6 %
Guides that discuss it
Sources
Nouryon, Dissolvine GL brochure (2022): GL-47-S, GLDA at least 47.4 %, about 1400 kg/m³ at 20 °C; "GLDA is extremely stable especially under alkaline conditions"; "GLDA is an authorized chelating agent for use in soaps (COSMOS".
Nourish Us Naturals, tetrasodium glutamate diacetate: "0.1%-1% (typical use is 0.25%-0.5%)".
Cosmetic Ingredient Review, amino acid diacetates (2021): GLDA up to 0.28 % in bath soaps and detergents.
The highest concentration reported to CIR in industry surveys: what has been used, not a recommendation.