Dear Valerie: I’m using 0.25% disodium EDTA in a moisturizer but find it’s not really dissolving in the water phase. Should I be using it in the oil phase? 

—Chelatin’ Heart

Dear Chelatin’:

As a hair color chemist, I use a bit of EDTA (although the tetrasodium variety) in my work. It takes forever to dissolve if using the granules, but it eventually will dissolve. Be patient and toss it into your batch immediately after the water. This gives it the most amount of time. A little heat also helps, so you can try warming your water phase just a little, if your other ingredients don’t require cold addition.

If you still have dissolution issues, consider buying a pre-dissolved blend to add to your batch in liquid form.

Lastly, I recommend reducing the amount of EDTA; unless you need a significant amount of chelation (like in hair color, where metals pose a threat to consumers). I find this use level overkill. EDTA is thought to resist biodegradation in the environment, so don’t use more than necessary. Use less than 0.1% or choose a more environmentally friendly chelating agent.

Valerie George

askvalerie@icloud.com

Valerie George is a cosmetic chemist, science communicator, educator, leader, and avid proponent of transparency in the beauty industry. She works on the latest research in hair color and hair care at her company, Simply Formulas, and is the co-host of The Beauty Brains podcast. You can find her on Instagram at @cosmetic_chemist or showcasing her favorite ingredients to small brands and home formulators at simply-ingredients.com