BUT HOW DO YOU ACTUALLY CHOOSE A PRESERVATIVE?
Now that you know whether you need a preservative and the criteria for choosing one, I think it’s time to actually talk about HOW to choose one. Let’s do a couple practice rounds!
Example 1: Sugar Scrub!
Let’s pretend we make a simple sugar scrub! Our ingredients are sugar, olive oil, and essential oil. Since there are no water based ingredients, it doesn’t intrinsically need a preservative, however because it will be in contact with water, the recipe we’re following suggests Phenonip. We check out our favorite supplier and see that they have several preservatives listed, but not the one our recipe originally called for (Phenonip), so we will have to substitute it for something else… here’s how we choose:
- First we look at SOLUBILITY: Our pretend sugar scrub recipe is oil based, so we choose an oil-soluble preservative.
- Next we check pH ACTIVITY: We don’t know the pH of our preservative, so we decide to choose one that has a wide range of pH activity
- Finally we consider TEMPERATURE: Because our sugar scrub is cold processed and doesn’t need to be heated, we don’t need to worry about the temperature!
- And don’t forget, we always want to choose a BROAD SPECTRUM preservative.
After checking the preservatives our supplier has available, we see that Optiphen and Germaben II are the only ones that meet our criteria. They are both oil soluble, with a wide range of pH compatibility, and are broad spectrum. After looking closer however, we notice that Germaben II is only soluble in formulations with 25% or less oil phase. Since the oil in our recipe represents more than 25%, we decide to go with Optiphen and calculate its usage based on the total weight of our sugar scrub.
Example 2: Lotion
Next we decide to make a lotion. The ingredients called for are Water, Avocado Oil, Glycerin, Emulsifying Wax, Stearic Acid, Vitamin E oil, Fragrance Oil, and Liquid Germall Plus. We know our formula will need a preservative because it contains water, however we are going to be selling our lotions in the EU and due to usage restrictions of Liquid Germall Plus, we decide to look for another preservative… here’s how we choose:
- First we look at SOLUBILITY: Our pretend lotion will have both an oil phase and a water phase. Since our water phase makes up 80% of our lotion, we decide to go with a water soluble preservative
- Next we check pH ACTIVITY: We tested the pH of our lotion and found that it has a pH 6
- Finally we consider TEMPERATURE: Our lotion has a cool-down phase–we can either use the heated phase or cool-down phase to add our preservative depending on which once we choose.
- And don’t forget, we always want to choose a BROAD SPECTRUM preservative.
After checking the preservatives our supplier has available, we narrow it down to NeoDefend, and Iscaguard PFA. Both are water soluble, broad spectrum, with a pH compatibility that lines up with our lotion’s pH. After looking closer however, we see that NeoDefend can cause the pH to drift down. We decide that we would prefer to not have to worry about that, and choose Iscaguard PFA as our preservative.
Example 3: Conditioner Bar
This time we decide to make a conditioner bar. The ingredients called for are Cocoa butter, BTMS50, Dimethicone, Essential Oil and Optiphen. We used all of our optiphen making sugar scrubs, and now we need a new preservative!
- First we look at SOLUBILITY: Our pretend conditioner bars will be completely oil based, so we need to choose an oil soluble preservative.
- Next we check pH ACTIVITY: We tested the pH of our conditioner bar and found that it has a pH 5
- Finally we consider TEMPERATURE: Our conditioner bar will need to be poured while it is still hot and fluid, so we will need a preservative that can withstand high temperatures
- And don’t forget, we always want to choose a BROAD SPECTRUM preservative.
We check our cosmetic supplier and, unfortunately, we don’t see any preservatives that we recognize. Rather than throw in the towel, we decide to use the INCI names of the preservatives our supplier has listed and look each one up online. We discover that one of the oil-soluble preservatives our supplier has listed, Phenoxyethanol (and)Ethylhexylglycerin, goes by the trade names Plantaserve E, and Euxyl PE 9010. We recognize those preservatives as ones suggested in the BFF Facebook Support Group. On further reading, we verify that it is oil soluble, works within our desired pH range, and can withstand high temperatures. We decide to go with this preservative for our conditioner bars.
This might seem overwhelming and exhausting to have to do over and over, which is why it’s more than likely that you’ll find two or three preservatives that you use on a regular basis and stick with them for the most part. I know it can be frustrating when you have a recipe or formulation that calls for a specific preservative that you can’t find in your country, let alone your regular suppliers!
It takes time to learn the many different properties of preservatives, and even then, the cosmetic industry is having a huge push at the moment for effective ingredients that are “free from” which means new preservatives come out all the time! While I don’t always agree with the free from movement, I can definitely see the value in providing more options for more people around the world!
As you continue to learn more about preservatives you will inevitability build your knowledge-base, but in the meantime, you can check out this new page we have added to our website. In it, we are slowly compiling an extensive list of preservatives and their components. We have read through hundreds of tech sheets, SDS sheets, manufacturer websites, and scientific journals to get solid, dependable information for you–straight from the horse’s mouth. Need to know if a preservative is oil soluble or has restrictions in your country? Check the chart and see! Don’t see your favorite preservative listed? Let us know and we’ll add it! Why? Cause we want you to be a happy maker, that’s why!
Happy Making!