Dear Valerie: I often see isopropyl alcohol on the ingredient lists of conditioners and I was wondering if you could help me understand its function and how much I would need to add. —IPA Insights

Dear IPA:
I am not aware of isopropyl alcohol (IPA) intentionally being added to conditioner bases. Generally, you add a solvent (like IPA) when you need to dissolve another ingredient into your system. If you are reading an ingredient list for a conditioner and see IPA, it’s likely a sub-ingredient of another ingredient.

For example, if a plant was extracted in IPA as the solvent, and is carried in the solvent, one might need to include IPA on the ingredient list—and likewise if the extract is in glycerin, glycerin would be included on the ingredient list.

On a conditioner ingredient list, however, IPA is unlikely to be from a plant extract. The most common reason for its inclusion is due to the conditioner containing behentrimonium chloride (BTMC). Some grades of BTMC use isopropyl alcohol as a solvent, and therefore, the INCI list requires listing IPA. It’s usually only present in the 80 or 85% active versions of BTMC. Therefore, when I see both BTMC and IPA on an ingredient list, I know the formulator probably used this percent active grade of BTMC.

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Valerie George
[email protected]
 
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