When to add a chelating agent?

Formulating

When to add a chelating agent?

Posted by beautysci on August 10, 2015 at 3:19 am

When should a chelating agent be added to a formula? I understand why it should always be added to such formulas as face/body cleansers, shampoo, conditioner. But sometimes I see a chelating agent in liquid foundations, but not always. So I am not sure in what cases it should be added.

Thank you.

Chemist77 replied 9 years, 6 months ago 6 Members · 10 Replies
10 Replies

MarkBroussard

Professional Chemist / Formulator
August 10, 2015 at 1:08 pm

I generally always add a chelating agent. Depending on the chelant you use, the chelant will also provide some preservative boosting effects.
Bobzchemist

Member
August 10, 2015 at 6:12 pm

Maybe a better question might be - Why do some formulators feel that they do not need a chelating agent in their formula?

One answer, two question:

1) Answer - If your water supply is very good and free from minerals, you might not think you need a chelating agent

2) Questions - What do chelating agents do? What ingredients are in a liquid foundation (that are not in most other products) that might make a formulator not want to use a chelating agent?
OldPerry

Professional Chemist / Formulator
August 13, 2015 at 3:06 pm

@Bobzchemist - one answer could be that they are trying to formulate natural and the easiest chelating agents to use EDTA are not allowed.

But I agree with everything said thus far.

If your question was when to add it to a formula (as in when in the batch process is it added) we always added it as one of the first ingredients. Generally, powders should be added first to give them adequate time to go into solution.
Bobzchemist

Member
August 13, 2015 at 7:09 pm

@Perry - the answer I was trying to guide @beautysci towards is that some of the colorants that would typically be used in a liquid foundation will complex with any/every chelating agent and render it ineffective. Also, the chelant/colorant combination may increase the instability of the product.
beautysci

Member
August 13, 2015 at 7:52 pm

@Bobzchemist, what if you are using all treated pigments in the formula?
Bobzchemist

Member
August 14, 2015 at 3:56 pm

Sadly, most treated pigments aren’t treated thoroughly. At best, they form a mesh-like structure around each of the the pigment particles.

So, since chelants are used to remove metals, they will complex with any of the iron oxides in the liquid foundation, treated or not.
Chemist77

Member
August 14, 2015 at 4:53 pm

@Bobzchemist someone in one of tbe previous posts mentioned sodium phytate as a chelant, do you think this too will interfere with pigments??
Bobzchemist

Member
August 14, 2015 at 5:07 pm

All chelating agents are specifically used to complex with metals - that’s what makes them chelating agents.

https://en.wikipedia.org/wiki/Chelation

And, it’s more that the pigments interfere with the chelating agents, rather than the other way around.
NVaughn

Member
August 26, 2015 at 7:45 am

Realize Beauty very recently did a piece on chelating agents. She is a big fan of sodium phytate. I don’t recall her mentioning anything about pigments but she did point out cost of the ingredient. You might try adding a question on her post.
Chemist77

Member
August 26, 2015 at 10:06 am

Thanks @NVaughn