What it is
Tetrasodium glutamate diacetate is a salt derived from glutamic acid that sequesters metal ions such as iron, copper, and calcium in a formulation. By binding these ions, it helps prevent the discoloration, rancidity, and breakdown of sensitive ingredients and supports preservative performance. It is frequently chosen as a readily biodegradable alternative to older chelating agents like EDTA.
Safety & warnings
Tetrasodium glutamate diacetate is used at low levels and is generally well tolerated, with a low expectation of irritation or sensitization in the concentrations found in skin-care products. It is not considered comedogenic. As with most chelators, it functions as a minor processing aid rather than an active.
Origin & sourcing
It is produced synthetically, with the glutamic acid portion typically sourced from fermentation of plant-based feedstocks, then converted to the tetrasodium diacetate salt.
Questions everyone asks
What does tetrasodium glutamate diacetate do in sunscreen?
It binds trace metal ions in the formula, which helps keep the product stable and supports the preservative system so the sunscreen stays consistent over its shelf life.
Is it a more eco-friendly alternative to EDTA?
It is often selected because it is readily biodegradable and serves a similar chelating role to EDTA, though both are used at small amounts.