"I only use natural products; I won't use any products with preservatives on my skin!"
Wow, I wish I had a dime for every time I've heard that statement, which usually turns out to be false. The bottom line: most consumers do not have the patience or the education to use all natural, preservative-free products for daily skincare.
Truly preservative-free products have very short shelf lives, particularly if those products contain water. These items must be purchased in small quantities; carefully stored (ideally under refrigeration); and require fresh, sterile applicators with each use to avoid bacterial or fungal contamination (Yes, even clean fingers have enough bacteria to contaminate a freshly made, preservative-free face cream). Be honest. Do you have the time or patience to use these products in a manner that will allow them to remain relatively uncontaminated?
The answer for most consumers is an unequivocal "NO". Most personal care products need to have shelf life of approximately two years duration. If you read the ingredient list on virtually all natural cosmetics at the neighborhood health food store, they will undoubtedly contain artificial preservatives. There's simply no way around the issue.
There are manufacturers who skirt the issue by claiming they have invented a proprietary natural preservative for their product line. These "preservatives" often contain ingredients such as naturally derived vitamin E, rosemary extract, neem oil or undisclosed essential oil blends. They may extend product shelf life by two or three months, but are not true preservatives. For instance, rosemary extract and vitamin E are both antioxidants. Their presence will delay oxidation of a lotion or cream, but will not prevent spoilage due to bacterial or fungal contamination.
It is possible for certain essential oil blends to have a preservative effect, but in order to do so, the blends would need to be used in such massive quantities that product aroma would be significantly altered and the oils would interfere with the action of other product ingredients, not to mention product texture.
Grapefruit seed extract has been highly touted as a natural preservative, but research has shown that it is adulterated with a chemical agent which actually provides the desired effect. As respected herbalist and aromatherapist Mindy Green has stated, "Grapefruit seed extract is a complete scam."
Aromaceuticals serves the preservative-free market by producing truly natural, vegetable oil-based personal care products, but these are sold in small containers and have a shelf life of six to nine months. Yes, I use them on my own skin. Yes, I've had to throw out batches of oxidized product. And yes, as someone with a paraben allergy, I sometimes resort to using other companies' products, provided they contain minimal artificial preservatives.
In the end, it all comes down to some very personal choices. Take a little extra time to create your own, one-time-use kitchen cosmetics such as masques and oil-based serums. Keep a bottle of hydrolat in the refrigerator to mist over your face as a daily toner or aftershave. Read ingredient labels carefully, and choose products containing minimal artificial preservatives. Buy from companies with good reputations and whom you trust. This is a subject where it's impossible to fully walk your talk, but with a little care and planning, you can come to a compromise that suits your lifestyle.