What is Period After Opening?

Cosmetic’s Period After Opening (PAO) refers to the period of time that a product remains suitable for use after the primary container has been opened. It is two distinct concepts from the "Expiration Date" of the product. Expiration date refers to the shelf life of the product in its "unopened" container under the storage conditions indicated on the product label. The concept of PAO appeared in 2003/15/EC and is applicable to cosmetics with a shelf life of 30 months or greater. However, different regions or countries have different requirements for PAO. For example, there is no PAO label requirement for cosmetics sold within the United States. However, one should expect the FDA to ask for supporting evidence of the PAO during an inspection.

The PAO symbol is a graphic symbol that depicts an open cosmetic pot and is used together with a written month or year. No matter what your makeup is, you'll likely take some precautions to not oxidize the formula or texture. For example: always close pots and bottles after use; avoid exposing product to sunlight; keep away from heat sources, etc.

For customers who want to determine the PAO of their products, they may be confused about how to conduct the experiment. Indeed, there is currently no officially recognized or universally accepted protocol for determining PAOs. So, in order to make the data accurate and not questionable by consumers and regulators, you need to develop a more rigorous protocol. A simple protocol would be to open and reclose product containers, just as a consumer would upon the first usage, and then place the reclosed containers into a controlled-environment stability chamber. Periodic assessments would be performed until the product is no longer deemed “suitable” for use. A more rigorous approach might include periodic assessments of the “very same” product container over time, since the repeated opening, closing and removal of the product from its container would more closely mimic consumer usage.

Experiments that may provide supporting data for PAO include:

• Microbial Challenge Test
• Preservative Test
• Stability Test
• Packaging Test
• Texture Measurement
• Experience with Similar Formulations and Products
• Consumer Habits and Practices

Creative BioMart's cosmetic stability testing is GMP compliant. We provide customers with customized services to test raw materials, new formulations, finished products and new packaging. We use advanced and upgraded equipment to collect specific temperature and humidity conditions to simulate transportation, storage and use conditions. According to different product types and different needs of customers, additional chemical tests can also be used to detect the levels of certain active ingredients, such as sunscreens and vitamins. Our cosmetic stability research can provide customers with high-quality stability, compatibility, and storage solutions.
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