Cosmetic manufacturing facilities must meet specific requirements to ensure that products are safe and effective and to maintain consumer confidence and comply with regulations. What are these requirements?
June 27, 2023
If you are already clear about what a stability study is (and if you are not clear about it you can see the entry in our Blog), surely the question arises as to whether it is necessary to put the PAO or if the expiration is enough. Or maybe you are wondering what exactly is the PAO.
Understanding the difference between these two concepts is not so simple. To do so, it is necessary to think about the entire life cycle of a cosmetic.
Both concepts are part of the stability section of the Information Dossier and are obtained in the development phase, when we are testing and proving our product.
On the one hand, we have the Expiry Date. This is the time during which the product complies with the specifications. That is, the time during which it remains correct and we can use it as if it had just left the factory. It is essentially the time during which the manufacturer can ensure that it is safe to use. After this time, the manufacturer cannot ensure that its physical, chemical or microbiological characteristics are not altered and therefore that the product continues to maintain its safety and functionality.
R1223/2009 states that if the expiration date is more than 30 months from the date of manufacture, it is not necessary to indicate this on the product labeling. This is so because on the one hand it is assumed that cosmetic products have a turnover greater than this period and on the other hand that if the product remains stable for 30 months it is because it is very stable and is little affected by environmental alterations and degradation factors.
Therefore, it is only mandatory to include the expiration date for those products in which the expiration date is less than 30 months. For products with a best-before date of more than 30 months, the inclusion of the expiration date is voluntary.
In any case, either because we are obliged to do so or because we do so voluntarily, the expiration date must be indicated preceded by the legend "best before the end of ..." or by the hourglass symbol:
Considering that the legend has to be included in all languages appearing on the label, the symbol is usually the most advantageous option.
PAO stands for Period After Opening. As its name indicates, it is the time that a product maintains its specifications once the package has been opened (and is therefore in use).
We are therefore also talking about a concept related to stability and as such, it is closely related to the scale of degradation of a product in the same way as the "Use by" date. However, in this case it is much more directly influenced by its first use or first interaction with the consumer (and the inevitable risk of microbial contamination therein) and contact with the environment.
Therefore, to determine the ODP, in addition to the stability study, other additional data are required, such as the size of the package, the possibility of contact between the consumer and the unused product, the microbiological quality of origin, the results of the Challenge Test, among others.
The ODP can be determined experimentally, in what we call an in-use stability study, or theoretically by considering the impact of each of the elements mentioned above and the sensitivity of the target population and the application site.
Single-use products (single doses) are exempted from the ODP marking requirement, since it is assumed that once opened they are used in their entirety, and those that are not in contact with the exterior, for example, aerosols or other devices that prevent the remaining product from coming into contact with the user or the environment. Products that are not expected to deteriorate over time in a way that would make them unsafe, such as alcoholic or anhydrous products, would also be exempted.
However, as in the case of the Expiration Date, its inclusion may be voluntary.
The ODP will always be less than the expiration date, and is indicated using the following symbol:
The number of months that the product can be safely used after opening is indicated inside the jar followed by the capital letter M.
As we have seen, both concepts are related, but they are not the same. The best-before date will mark the period that our product can be on the shelf in a store, or in our warehouse waiting to be sold. The EOP marks the time that the consumer can safely use the product from the time he buys it and starts to use it.
In addition, a cosmetic can carry one of them, both or neither; let's look at an example of each:
We hope we have helped to make everything much clearer now!
Find out more about Celia Campos, Technical Director and co-founder at MuttuLab, author of this article.
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