An issue that causes headaches in our work is the preservation of our products. In social media, there is such an argument about preservatives and people have been divided into 2 camps: the side of the professional formulators calls for the necessity of preservation and the other side a movement that talks about “natural” products without having the basic knowledge of chemistry. What is natural and what is not, is a big topic of discussion. For example, what is the meaning of a velvet handmade cream if it is not safe to use?
The addition of a preservative to our products is NECESSARY and I write it with huge capital letters because it prevents the microbial growth (microbes, bacteria, mold, yeast) and prolongs the products’ shelf life keeping them free from contamination. To be more precise, they stop the growth of pathogenic microorganisms as long as they are in the form of spores, destroying their cell membranes. Thus the product creates a clearly hostile environment that prevents the incubation of microbes. An infected product is at least dangerous as it can cause many skin issues, from dermatitis to staphylococcus and tetanus.
The preservative is primarily used in products containing water such as floral waters, hydrosols, aloe vera, glycerine, etc. or in products that come into contact with water, such as scrubs which may be anhydrous but they are used in the bathroom, in humidity and we touch them usually with wet hands.
In the case of scrubs: usually their composition is consisted of sugar, salt & oils or butters. The common sense says to use an oil-soluble preservative. However, we do not protect the product this way, as the preservative is locked only in the oil composition, which means that when the scrub comes in contact with wet hands, the oil-soluble preservative can not in any case protect the product from the mold which will start growing immediately. So what do we do? In this case we use a water-soluble preservative which we combined with the oils using an emulsifier.
Vitamin E and extracts from rosemary or grapefruit are antioxidants and not preservatives. They prevent the oxidation of oils and butters by slowing down the rancidity process. They do not in any way protect against bacteria, fungi, yeast and mold.
The refrigerator is neither a preservative nor an antioxidant, as a product placed in the refrigerator without the addition of a preservative can only be stored for 5 days, just like our food. Would you eat something from the refrigerator if you knew it's been there for over a week? the answer is one: NO. So how can you apply something on you that you would not otherwise eat?
We just started a long journey into the world of preservation. In a next article, we will further analyse how preservatives exactly work.