Sodium Benzoate (NaC6H5CO2) is used as a preservative worldwide. It is generally Recognized As Safe (GRAS) throughout the world.
The active part of the salt is benzoic acid, an organic acid (C6H5COOH) which is the actual preservative. The salt itself does not show any preservative activity. Sodium Benzoate is transformed into the free benzoic acid by lowering the pH of the solution. This can be done by adding any acid such as ascorbic acid (vitamin C) or citric acid (found in citrus fruits mostly).
Fruits and vegetables contain Benzoic acid. Plums and prunes have a relatively high content of Benzoic Acid (around 0.1%).
In the body, Benzoic acid is the result of the _-oxidation of fatty acids with odd numbers of carbons. Small amounts may also be formed in the large intestine from phenylalanine or tyrosine. Benzoic Acid reacts with glycine (an amino acid) and is excreted as hippuric acid (a constituent of urine in horses) in the human body.
There is at this time only a suspicion that benzoic acid is transformed into benzene with the presence of ascorbic acid, mineral ions and in certain condition such as in the presence of light and heat. The experiments have been only conducted on soft drinks and are not yet conclusive.
Benzene is an organic chemical compound composed of what is called an aromatic ring: C6H6. It is considered to be carcinogenic. These are some of the products which contain benzene groups (rings):
Benzyl Penecillin: C16H18N2O4S
Paracetamol also called Acetaminophen also called Tylenol: C8H9NO2
Phenols: C6H5OH. Many essential oils are phenols (ex: Eugenol, Thymol), some are hormones (ex: Estradiol).
Sodium benzoate is at the present time considered Low Hazard (0) by EWG’s Skin Deep Cosmetics database. Oblige by Nature, one of Naprodis’ brands is considered low hazard (0-1) by EWG’s Skin Deep Cosmetics database. Other alternative is to use Potassium Benzoate, but this has also been reported as being transformed into benzene, just the same as sodium benzoate. This doesn’t solve the problem. Another is to use Potassium Sorbate (the salt of sorbic acid), but this compound has been considered a mild hazard (3) by EWG’s Skin Deep Cosmetics database. Regarding Grapefruit Seed Extract (GSE), Naprodis has been using it when it was manufactured by Biochem. Back then Naprodis was able to purchase the food quality. Now that the manufacturer has sold its manufacture to another company, the new company is no longer manufacturing the food quality and only manufactures the topical GSE. This has raised a red flag at Naprodis since this product has always been considered by Europeans as containing parabens in glycols, triclosan or benzethonium chloride solutions. Naprodis has abandoned the use of GSE since 2009. We are still looking to replace Sodium Benzoate in our products, however, we have not yet been able to replace it in all of our products since there is no alternative other than using alcohol which is not a good choice when it comes to skin products. We have totally removed Sodium Benzoate and other preservatives in our Phybiosis products (Aromune, Bronerome, Sinerome and Kinderome). These products are now preserved only by the presence of essential oils. Until we do find a satisfactory alternative, we believe that Sodium Benzoate is still the least toxic preservative to be incorporated in skin care products.