Part 10: Shelf Life
As mentioned previously, the most significant challenge in formulating your own cosmetics involves the limited shelf life of handcrafted cosmetics. Unless you add a preservative, your cosmetics will not have the same shelf life as their commercial counterparts. Most of us tend to keep and use our cosmetics until they run out instead of properly disposing of them after a few months. Even heavily preserved commercial cosmetics can become breeding grounds for bacteria because the cosmetics come into contact with our skin. Eye shadow and blusher brushes touch the powders, then gloss over our skin and carry bacteria and oils back to the powdered cosmetic the next time the brush contacts the powders. Mascara brushes touch our lashes and then go directly back into their tubes carrying the oils and bacteria from our lashes directly into the liquid mascara. When you create your own cosmetics, the shelf life is much more limited, but you can keep track of the date that you made them. Because they're less expensive to make, you can replenish your personal cosmetic apothecary with fresh new cosmetics.
To help extend the shelf life of your products, keep your makeup applicators clean. Regularly wash them with gentle shampoo, thoroughly rinse them and allow to dry. Clearly label your products and include the date that you made them. Consider also making note of the date that you first begin using the product, especially if time passes in between. A good rule of thumb is to limit use of your cosmetics that you make based on these recipes to 1-2 months. This guide does not include any water based cosmetic recipes. Should you begin to make any cosmetic recipes that include water or hydrosols, they will have risk of growing mold and harboring more bacteria. Their shelf life will be shorter if left unpreserved.
If you choose to include preservatives (as you surely will need to if you ever intend to sell your creations), you will need to research the array of preservatives that are available, and learn which preservatives are most effective for each cosmetic application. Preservative types and usage rates are complex subjects, and most preservatives are not completely natural. For more information, visit FNWL's Library article entitled Using Preservatives to Extend the Shelf Life of Your Products.