Question: What does active mean in our surfactants?

Ruth wrote to ask me this question: What does it mean, when a ingredient says it is 25% or 30% or etc. active? Do you use them differently? Depending on the active %?

Great question, Ruth!


We see this mostly with surfactants in that the ingredient contains 25% of the active ingredient - something like cocamidopropyl betaine or sodium cocoyl isethionate (SCI) - with the rest being filler, such as water, preservative, glycerin, and so on. In theory, we use those ingredients differently. For instance, if the maximum safe usage level of a surfactant (let's call it foamy A) is 20%, and it's 40% active, then we'd use a maximum 50% of foamy A in a product. If another company makes their own version of foamy A at 80% active, we'd use 25% in a product to get to that maximum amount.

Let's stop and do the math for a second...If you need 20% active ingredient, and your bottle contains 40% active ingredient, then using 50% of the whole ingredient in your product will give you 20%. If you need 20% active ingredient, and your bottle contains 80% active ingredient, using 25% of the whole ingredient in your product will give you 20%. 

It's hard to say if the active will have a difference on the product or not. If you're using something like 25% cocamidopropyl betaine versus 30% cocamidopropyl betaine at 10% in your product (meaning you have 2.5% cocamidopropyl betaine in one product, 3% in the other), it might not be immediately noticeable, but using something like 40% active surfactant versus 25% active surfactant at 20% will be, so it's difficult to offer an across the board kind of statement about it.

Also heck what makes up the non-active percentage in the product. Is it water, alcohol, preservative, various humectants, and so on? In the case of powdered surfactants, does it contain extra fatty acids, extra fatty alcohols, or other emollients that bother someone with oily hair or skin? These things might have an impact on your product as well!