Let’s stir up some magic in the lab with today’s hot topic:

Chelators in cosmetic formulations and whether you actually need one in your O/W lotion.

After publishing our first article on chelating agents in cosmetics, we received a thoughtful email from one of our readers. On top of replying privately, I thought it would be absolutely great to share the question here because I am certain many formulators are asking themselves the very same thing.

Here is the full question we received: 

“Hello I read your article on chelators and especially noted this one paragraph: ‘Clean-positioned brands typically choose sodium phytate or GLDA for example’.. I make what I think is O/W lotion formulations with botanicals and I use BTMS 50 and Cetyl Alcohol and Optiphen Plus for preservative. I also noted this paragraph: ‘Cationic conditioners, W/O emulsions, some clays, polymers, carbomers, etc usually won’t require a chelator at all’. so do I need to use a chelator? Thank you so much” K.T. 

This is an excellent question because it touches on formulation chemistry, preservative efficacy, polymer stability, clean beauty positioning and regulatory understanding all at once. So let’s unpack it properly.

What Do Chelators Actually Do in Cosmetic Formulation?

Before deciding whether you need a chelator in your lotion, we must go back to fundamentals.

Chelating agents such as Disodium EDTA, Tetrasodium EDTA, Sodium Phytate and Tetrasodium Glutamate Diacetate bind polyvalent metal ions such as calcium, magnesium, iron and copper.

These metal ions matter because they can:

• Catalyse oxidation of oils and botanicals
• Reduce preservative efficacy
• Interact with anionic polymers
• Cause colour instability
• Destabilise emulsions in certain systems

Chelators work by binding those metal ions so they are no longer chemically active in the aqueous phase. They are not preservatives. They are not antioxidants. They are metal ion management tools.

Understanding this changes everything, because if there is no relevant metal ion risk, there is no problem to solve.

Cationic Systems and Chelators: A Compatibility Question

Chelating agents such as EDTA, GLDA and Sodium Phytate are anionic molecules. Cationic surfactants like Behentrimonium Methosulfate are positively charged.

When anionic and cationic species meet in a formula, ionic interactions occur. In some cases, they can form complexes. In others, they can reduce performance of the conditioning agent. In cationic conditioners, chelators are often unnecessary because:

• The system is less sensitive to metal ion interference than anionic surfactant systems.
• The lamellar structure formed by fatty alcohol and quaternary surfactant is not highly destabilised by trace calcium in the way anionic gels are.

So the statement from our previous article that cationic conditioners usually do not require a chelator still holds. But this is not a universal rule. It is context dependent.

Chelators and Carbomers: Clearing Up the Confusion

In our previous discussion, we also addressed a common myth: that chelators destabilise carbomer systems because they introduce sodium ions and collapse the gel.

Let’s clarify this properly.

Carbomers are crosslinked polyacrylic acid polymers. Once neutralised, they become negatively charged and swell in water.

They are sensitive to electrolytes, particularly divalent cations like calcium and magnesium. These ions can screen charges, reduce repulsion and decrease viscosity.

Chelators at 0.05 to 0.1 percent do introduce a small amount of sodium. However, sodium is monovalent and far less disruptive than calcium or magnesium.

Gel collapse usually occurs in high electrolyte systems such as magnesium chloride lotions, sea mineral gels or high salt hair styling products. In those systems, every additional ionic contribution matters.

In a standard cosmetic gel, low level chelators rarely cause irreversible thinning on their own.

Clays and Cation Exchange Capacity

Another part of the discussion involved clays such as bentonite or kaolin. Clays possess cation exchange capacity, meaning they can adsorb certain metal ions at their surface. They can bind some cations, but they do not selectively inactivate iron or copper in the same way a chelating agent does. They also do not prevent redox catalysis in the aqueous phase. But the risk is considerably decreased. Especially if your clay formula is mostly anhydrous or low water, the metal mobility is reduced and a chelator may be unnecessary.

Do Clean Beauty Brands Need Chelators?

Our reader specifically mentioned clean positioned brands choosing sodium phytate or GLDA. Sodium phytate and GLDA are often selected because they are biodegradable and more compatible with natural marketing positioning.

From a formulation perspective, they function similarly to EDTA by binding metal ions. The decision is not about clean versus synthetic. It is about metal management.

If you do not have a metal ion problem, adding any chelator for marketing reasons alone does not make your formula more stable.

If you do have a metal driven oxidation risk, choosing a biodegradable chelator can absolutely align performance and brand positioning.

So, Does This Reader Need a Chelator?

Now let us answer the original question directly.

If you are making an O/W lotion with BTMS 50, cetyl alcohol and botanicals, preserved with Optiphen Plus, and you are using purified/deionised water and quality extracts, a chelator is not necessarily needed.

• Your system is cationic
• You are not relying on carbomer viscosity
• Your preservative system is not heavily metal sensitive

To be extra sure and rely on practice rather than theory, you can test stability with and without a chelator. There is nothing better than to learn through experience rather than simply follow what you’ve been taught!

Formulation is not about adding ingredients because they appear on trend. It is about solving real chemical risks.

Let me leave you with my final thoughts on Chelators in Cosmetic Formulation

Chelating agents are powerful but highly misunderstood tools in cosmetic chemistry. They are targeted solutions for metal ion management in aqueous cosmetic systems.

When used intentionally and at appropriate levels, they improve oxidative stability, support preservative performance and enhance long term product quality.

When used blindly, they add complexity without solving anything.

As formulators and brand owners, our responsibility is not to follow ingredient trends. It is to understand the chemistry behind every percentage point in our formula.

If you are developing advanced emulsions, scaling production or preparing for regulatory review, and you want your formulation strategy reviewed from both a technical and compliance perspective, you can explore our formulation services here.

Here’s to formulas that work and brands that thrive!

From my lab to yours,

Rose