Tetrasodium ethylenediaminetetraacetate, (phew!) or commonly abbreviated to tetrasodium EDTA, is a common ingredient in skincare products.Â You might have seen this in Â your shower gel, soap bar or shampoo. Ever wondered what it does? Here’s what I learned about it today.
At first I assumed it was some kind of preservative. I was mistaken–it’s actually a chelating agent. What it does is to ‘soften’ hard water, i.e. water that has a lot of metal ions, particularly calcium and magnesium, in it. Soap cannot lather in hard water, so you can see why tetrasodium EDTA is an important ingredient in soaps and bath gels.
We don’t encounter this problem in Malaysia, but in quite a number of countries such as the UK, it’s a fairly common issue to deal with. I remember when I was traveling in Bali with my family about 2 years ago, and we tried showering there with my soaps as usual. The water was hard (I didn’t know that). And the shower experience was awful. My soap wouldn’t lather and there was this icky, scummy feeling left on my skin when I was done. My hair was in a right mess. It took me a while to figure out what the matter was.
So please note that my soap may not lather very well in places where the water is hard, or has a high level of metal ions in it. :p I never thought much of this chemical as a soap additive, but now I appreciate why it is an important component in mass-produced bath products.
Well, now you know what tetrasodium EDTA is! If you found this post useful, please share it with your friends and family.
If you’d like to understand this chemical better, here are some links that I personally found quite helpful: