Are you ready to make your own body and skin care items? Great! Making your own bath and beauty products is rewarding and fun, but you need to make sure that you're being safe with your craft - and that involves using preservatives. Read on to learn about the basics of using preservatives: what they are, when to use them and how to test your product. We're going to get a little scientific, but stick with me!
1. What Is a Preservative?
Preservatives are ingredients you add to your skin care formulas to prevent the growth of bacteria, yeast and fungi. Some preservatives, like Germall Plus, Otiphen, or Phenonip are broad spectrum, which means they protect against all three. Preservatives can also be limited, like potassium sorbate or natural botanicals. These can be used alone or combined with other preservatives to achieve broad spectrum protection.
2. Which Products Need Preservatives?
Basically, any time you formulate a product with water, you will need a preservative.
Bacteria, yeast and mould need water to survive, and while we can try to mix things in a sterile environment, eventually contaminates will get in. Generally, you can expect a water-based product to last three to five days with refrigeration before going bad. So if you are making beauty products to sell or give away as gifts, it's best to be on the safe side and always use a preservative!
The toner and moisturizer above are both made with water and will need a preservative. Solid bar soap is an exception. Soap is also made with water but it doesn't need a preservative because the pH level is too high to allow for bacterial growth.
The oil perfume and solid perfume products above do not need a preservative because neither contains any water.
Note: While you don't need a preservative for anything that doesn't contain water, you may want to add one if your end product is likely to come in contact with water — like a sugar scrub.
3. What Kind of Preservative Should I Use?
Choosing a preservative is a personal choice, and fortunately there are many options available.
Parabens are preservatives and widely used in mainstream beauty products and can be added to the oil phase of formulation. Phenonip is a common oil-soluble, broad-spectrum, paraben-based preservative. If you want to preserve an oil-based sugar scrub that might come in contact with water, phenonip is a good choice. You can add this to the oil phase of your lotions.
Note: I can't ignore that parabens have gotten a bad rap with allegations that they are unsafe. The fact remains that parabens haven't been proven to be unsafe and are very widely tested, but since there are so many alternatives, it's easy to avoid them. The great thing about making your own products is that you can choose for yourself!
Germall Plus and Otiphen Plus are both broad spectrum alternatives that do not contain parabens and are water soluble.
Germall Plus is very easy to work with and is added during the cool-down phase of lotion making. It's made with propylene glycol, diazolidinyl urea, and iodopropynyl butylcarbamate. Overall, Germall Plus is a formaldehyde releaser, but you can use it at a very low rate (0.1 per cent to 0.5 per cent of your formula) and still achieve broad spectrum protection.
Otiphen Plus is made of phenoxyethanol, caprylyl glycol and sorbic acid and is my preservative of choice. Add this to the heated water phase when making lotion. It's paraben-free and not a formaldehyde donor but requires a slightly higher usage rate (0.75 per cent to 1.5 per cent of your formula) and can sometimes cause an unstable emulsion. Working with Otiphen Plus can require more experimentation, but that’s half the fun, right?
Organic acids like sorbic acid and potassium sorbate can also provide preservative protection. These are not broad spectrum and are most effective in preventing fungal growth. You will usually see these combined with other products or as ph adjusters.
What if you want to be all-natural and use a preservative that that contains no chemicals at all? This is possible, but you will need to add the preservative at a much higher rate to be effective. Leudical Liquid, PhytoCide Elderberry OS, Willow Bark Extract and a few other botanicals could possibly be used as broad spectrum natural preservatives. Usage rates range from four to eight per cent, however you need to properly test for effectiveness before going down this route.
4. Is an Antioxidant a Preservative?
The short answer is no.
Antioxidants like tocopherol (vitamin E), grapefruit seed extract or rosemary oil extract can help to extend the shelf-life of oil-based products by preventing rancidity, but they do not inhibit the growth of bacteria, yeast or mould like a true preservative would. Your best bet is to include an anti-oxidant but also use a true preservative for the best protection against contaminates.
Still with me? Great! So let’s say you’ve been formulating for a while and you're ready to take the next step in your journey to beauty-product making professionalism. This means testing. Testing allows you to make sure that the preservative you choose is doing its job. The easiest way to do this is with a check-it kit at home. You can get a check it kit here. Other testing alternatives are available, like sending samples off to a lab - but that’s a whole different post!
Now you’ve learned the basics about using preservatives when making your own skin care products. I hope this information was helpful! Remember, preservatives are necessary for any product containing water. While you may want to keep your products as natural as possible, nothing is more unsafe than a contaminated product. Experiment, test and have fun, but above all be safe.