So you want to make DIY skincare products.

If so, you have lots of company. The main question here is how to preserve them. This is even more important if you are thinking about making skincare products using natural ingredients and botanicals. Even DIYers should have a basic knowledge of how to preserve their products if they want them to remain safe and effective over time.

Why Is Preservation Important?

The ingredients themselves may have been contaminated by the supplier during extraction or transport.

You might inadvertently contaminate the product depending on where and how you create it (airborne particles, non-sterile utensils or containers, etc.)

The product may be improperly stored (high heat, improper container, exposure to sunlight, etc.)

The product may contain ingredients that require preservation like botanicals, clays and hydrosols, and there is none (more on this below

The product may have the right pH level for optimal growth (e.g. between 3 and 8)

Which Contaminants Do Preservatives Work On?

There are three main contaminants – bacteria, yeast, and mold. The most common contaminants are:

• Staph aureus – bacterium
• E. coli – bacterium
• Pseudomonas Euruginosa – bacterium
• Candida albicans (yeast)
• Aspergillus niger (mold)

These organisms have the potential to cause serious problems – even more so if you are making DIY cosmetics which go near the eyes. Regardless of where they go, who wants to spread these little guys on the skin?!

While there are some chemical compounds that protect against all three – like bleach – these are not candidates for skincare products. What usually happens is that manufacturers use a combination of preservatives that, when combined, effectively prevent bacteria, yeast and mold from growing in a formulation. Basically, wherever you have water, you have the potential to have one or more of these contaminants in your finished product. These organisms love water. Therefore, oil-in-water or water-in-oil emulsions MUST be preserved. Even if your product is refrigerated, the shelf life will be relatively short. You could get around this by using small containers (1 oz or smaller). However, if your product was already contaminated due to the situations mentioned above, these organisms can multiply in a relatively short period of time. Keep in mind that our skin hosts bacteria, so every time you dip your finger into the product, you are introducing contaminants. Why not be on the safe side?

Which Preservatives Are Effective Against Bacteria, Yeast, and Mold?

This requires that you do a little homework. There are many alternatives available to DIY crafters, and it’s important to review the details of each and to know the amounts that must be used. You may be asking if essential oils can be used as preservatives. The short answer is “No”. Essential oils are very potent plant extracts, and as such are difficult to standardize. They can also cause irritation in higher quantities, which you would probably need in order for them to work as preservatives. Thus, an essential oil combination that is effective against all three contaminants may be too overwhelming to be used in a skincare formulation. You will find a list of common preservatives in a link in the References.

How To Prevent Contamination With DIY Skincare Products

• Make your product oil-based or anhydrous – without water. Organisms cannot grow in an oil-based medium. The balms are all-purpose, super-moisturizing formulas containing antioxidants like Vitamin E and Rosemary oil, but no synthetic preservatives. Check out our body balms
• Don’t introduce water into your product – whether it is oil-based or not. With oil-based products, once you introduce water, if they are not preserved, then organisms will grow. This is especially true for products like sugar scrubs. Although many are oil-based, if you use them in the shower and get water into them, they have become
  contaminated.
• Use tubes or airless containers for your products. This is becoming more popular among major skincare retailers for their water-based products, and for good reason. Products in tubes and airless containers are not exposed to dirty fingers or outside contamination. This allows them to last longer with less rancidity.
• Adjust the pH of your product. One of the reasons why bar and liquid soap do not need preservatives is that their pH is generally 10 or above – not a friendly growth environment. The same goes for a pH below 4. It’s important to know what pH your final product is so that you can choose the right broad-spectrum preservative.
• Use high-sugar, high-salt or glycerin in your products. Most bacteria and yeast need water to grow, and sugar and salt draw water out of product it’s in. Glycerin works similarly, but must be in too high a concentration (70%) to provide a pleasant feel. However, its moisturizing properties make it a popular ingredient in skincare products.

Making your own skincare products can be instructional and fun. If done properly and with the right preservatives, you can craft something that you can be proud of, while ensuring safety. So whatever the reason for DIY skincare – whether it’s to avoid problematic chemicals like parabens, formaldehyde releasing preservatives, or fragrance, make sure that you do your homework and use techniques that will keep your product contaminant-free.

References:
Making Skincare website article on preservatives and resources
Scientific American article on salt and sugar preservation
Natural News article on parabens