What is polyquaternium-10?
In our first post about conditioning ingredients, we will tell you about the benefits of polyquaternium-10 (PQ10). PQ10 is basically cellulose that has been reacted a couple different ways. Cellulose comes from plants, and it’s also the most abundant polymer found in nature! How about that? The precursor to polyquaternium-10 is hydroxyethyl cellulose (HEC). HEC is used in a wide variety of applications from paints, coatings, drugs, household products, and also cosmetics. It’s a thickener and it also helps binding materials together. In paints, it helps the paint coat the wall completely.
When HEC is quaternized to make polyquaternium-10, it has the added benefit of being attracted to damaged parts of the hair where you need it most. Damaged hair is hard to comb, so adding PQ-10 to those parts improves combability and feel of the hair to the touch. It’s basically a seeking missile that will destroy your bad hair day! For more information on frizzy hair, go back and read our early post on the topic here.
Is polyquaternium-10 safe?
There isn’t a CIR report I could find to link on this product, but it’s been very heavily studied for cosmetic use for several decades. There is a report that can be found here. It puts the conclusions on the page but there is a full report available with all the data in a link on the page (it’s not free). If you want the bottom line here’s the conclusion. PQ-10 was neither an irritant nor a human sensitizer when tested at 2.0%. Cosmetic products containing up to 1% PQ-10 were not human irritants, sensitizers, or photosensitizers. On the basis of the information presented, it is concluded that PQ-10 is safe as a cosmetic ingredient in the present practices of use.
You would almost never have a good reason to use PQ-10 above 1% in a formulation. I’ve never seen it used above that amount in all my years formulating. It would probably make the formula a bit too sticky and unpleasant at high levels like that. The data show it’s commpletely safe.