Sodium Benzoate is the INCI name of sodium benzoate, a salt of benzoic acid. The compound is known for its preservative uses in various industries. In a cosmetic, it is an element of protection of the recipe itself against undesirable growth of microorganisms, and not a declaration of skin treatment.
Characteristics and context
The effectiveness of the preservative system depends, among other things, on the pH, composition of the preparation and the packaging used. Sodium benzoate may work with other components of such a system. The INCI list shows its name, but usually not the exact concentration. It should not be identified with benzene or with a whole group of substances with similar-sounding names. The presence of a preservative allows for a better understanding of the product's technology, but does not independently determine shelf life after opening.
Meaning and application
Preserving a recipe is a microbiological issue. The product may have a pleasant smell and still require appropriate protection against contamination. Contact with water, dosing method and how the user handles the packaging are important. Sodium benzoate does not act in isolation from these conditions: its role depends, among other things, on the chemical environment of the formulation. Therefore, the presence of one ingredient should not be treated as an independent proof of the durability of the entire cosmetic.
In practice
Substances that limit the oxidation of fats have a different task than the preservative system against the growth of microorganisms. These functions can coexist, but they are not interchangeable. The expiry date and indication of the period after opening should be read from the specific packaging, instead of deriving them from the INCI name. It is also worth keeping the exact spelling of Sodium Benzoate: the similarity of the sound of different chemical names does not mean the same structure, function or method of use.