Cosmetic and personal care products that are intended for storage at room temperature have two options for stability testing, realtime and accelerated testing. Many people are unaware that stability testing can be performed at an accelerated rate. Accelerated shelf life testing is based on the idea that a product that is exposed to extreme conditions will perish at a faster rate than a product stored and used under normal conditions. A general standard for accelerated testing, based on the Arrhenius Equation, is:
10 weeks at 45°C is equivalent to 1 year at ambient (~21°C) temperature.
The shelf life of a product is the recommended length of time that perishable items are considered suitable for sale, use, or consumption. Determining the shelf life of a cosmetic or personal care product is not easy especially due to the nature of use by consumers. When determining the shelf life of a product, you should ask yourself this question:
At what level of quality do I no longer want my product to be available to consumers?
This can be when one of the characteristics listed below changes significantly, or when the product is no longer just like new. Answering this question will help you determine how long your product will be suitable for consumers.
When testing a product for aesthetic and physical stability there are many characteristics to look for that will determine if the product is still of good quality over the designated use time. They are:
It is also important to test the product in the packaging it will be marketed in, as it will give the most accurate shelf life results.