What is PAO and how to determine shelflife

Article 19.c

The date until which the cosmetic product, stored under appropriate conditions, will continue to fulfil its initial function and, in particular, will remain in conformity with Article 3 (‘date of minimum durability’). The date itself or details of where it appears on the packaging shall be preceded by the symbol shown in point 3 of Annex VII or the words: ‘best used before the end of’. Indication of the date of minimum durability shall not be mandatory for cosmetic products with a minimum durability of more than 30 months. For such products, there shall be an indication of the period of time after opening for which the product is safe and can be used without any harm to the consumer.

Period after opening (PAO) OR best before date?

If stability is guaranteed for 30 months or more, a PAO symbol can be used. If stability is guaranteed for a period shorter than 30 months, a hourglass symbol with the date is used. This is called the best before date. Stability of a product is tested through a stability test.

Exemptions for a expiry date

Expiry date is not required for single-use products and products presented in containers that do not allow a contact between the product and the external environment (e.g. a pressurized container).

PAO duration

After understanding when a PAO can be utilized, the next step is to decide the number of months that can be indicated in the symbol. There is no strict regulation on how to approach this, but there is a method by the French Authorities (ANSES, prior called AFSSAPS) to determine the PAO duration. We call this the AFSSAPS method.

AFFSAPS parameters

The AFSSAPS method uses the following 5 parameters:

A. Formulation
B. Packaging
C. Estimated period of use
D. Application zone
E. Target population

For each parameter there are different levels 1 to 4, 1 to 2 for a risk considered low, and from 3 to 4 for a risk estimated to be significant.

For instance, packaging with an airtight pump would be assigned a low risk level of 1, while a jar with a large opening would be classified as a level 4 risk. This is because an airtight pump has very little chance of external contaminants entering the product, whereas with a large jar, there is a higher likelihood of contact with our hands. Another example is the target population; level 1 are healthy adults, while a significant risk level 4 are the target groups babies and elderly.

How to calculate the theoretical PAO

Each metric is assigned a score ranging from 1 to 4. The theoretical risk which estimates the theoretical PAO is the product of 5 factors:

Theoretical risk = A x B x C x D x E

The results are expressed as follows:
Theoretical risk ≥ 1 and ≤ 8 ⇔ PAO ≤18 months
Theoretical risk > 8 and ≤ 48 ⇔ PAO ≤ 6 months
Theoretical risk > 48 ⇔ PAO not applicable (review product design)

This gives you an indication of the PAO duration. It is up to the evaluator to justify any
choice, parameters, specifications and tests to be implemented to validate the theoretical PAO.