Tetrasodium EDTA is recommended for alkaline products, like most handcrafted soap (and can also be used in creams and lotions). EDTA works synergistically with your preservative to improve preservative efficacy. In soaps, it can counteract the defoaming action of hardness ions, reducing soap scum and improving lather.
Recommended Usage Rate: 0.1% for Preservative Efficacy
INCI: Tetrasodium EDTA