Cosmetic Preservatives Guide
Cosmetic preservatives are an important part of homemade bath and body care products. They help prevent mold and bacteria growth, which extends the shelf life of products and makes them safe to use.
They’re recommended for products made with water or products that may get water splashed in during use. This post offers a cosmetic preservative guide for different products like soap, lotion, and more. Keep in mind these are general rules and may be different based on your preference, how the product will be used, and whether you’re selling the product or it is meant for personal use. It’s a good place to start.
One factor to consider in homemade skin and hair care, and bath and body care products is the potential for mold growth. That can happen with any water–based recipe if it’s not handled properly. Before making lotion, you’ll need to sanitize all your tools in boiling distilled water. That includes spoons, bottles, and bowls—anything that will come in contact with the ingredients. Then, wipe the tools dry with a clean towel.
You’ll need to add a preservative at 0.5–1.5% of the total weight of the lotion. There are synthetic preservatives commercially available, but I prefer to use organic ones. Sea salt, Vitamin E, glucose (sugar), or essential oils (like black pepper or bay leaf) that contain the phytochemical compounds linalool and eugenol are good options.
Cold Process and Melt & Pour Soap
Preservative: No
You never have to worry about adding a preservative to cold process or melt and pour. They have a pH level of 9–10, which doesn’t allow mold or bacteria to grow. Just another reason to love handmade soaps.
Liquid Soap
Preservative: Optional
Amount: 0.5–1% of the total weight
Like bar soap, liquid soap has a pH level that doesn’t allow mold to grow. However, it does require distilled water for dilution. You can add a preservative to be extra careful or if you plan to sell it.
Lotions & Creams
Preservative: Yes
Amount: 1% of the total weight
Lotion always needs a preservative because it’s made with water. Without one, the shelf life will only be a few weeks. Check out our posts for a homemade rose body cream and a homemade babchi seed oil face cream.
Facial masks
Preservative: Yes
Amount: 1% of the total weight
Facial masks always need a preservative because they’re meant to hydrate the skin so they’re made with water. Without one, the shelf life will only be a few weeks. Check out our posts for a rosehip and lavender facial mask and a rose hyaluronic gel facial mask.
Body Butters
Preservative: No
This is a simple mixture of butter and oil. Because there’s no water and it will likely be applied to dry skin, don’t worry about a preservative. As always, you can add one if you plan to sell it. Check out our post for a homemade whipped rose body butter.
Scrubs and Bath Salts
Preservative: Optional
Amount: 1% of the total weight
While most scrubs and bath salts aren’t made with water, they are usually stored in the shower and can get water splashed in during use. We recommend a preservative for that reason. You can skip it if the recipe is for personal use and stored in a cool, dry area in between uses.
Bath Bombs
Preservative: No
Bath bombs don’t contain water so they don’t need a preservative. When choosing witch hazel to wet them, make sure it contains alcohol or already has a preservative.
Healing & First Aid Balms
Preservative: No
Like body butter, balms don’t contain water and they’re usually applied to dry skin. You don’t need to worry about a preservative. That goes for both body balms and lip balms.
Room Sprays, Linen Sprays, and Perfumes
Preservative: Yes
Amount: 1% of the total weight
If your recipe contains water, it will need a preservative. If not, check the ingredient list and make sure whatever you’re adding has one. That means you don’t need to add another one. The same goes for recipes that are oil based.
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Sources:
Preservatives Quick Guide
https://www.brambleberry.com/ingredient-information/additives/art0029-preservatives-quick-guide.html