Information about the period of time during which the cosmetic is suitable for use after first opening under appropriate conditions. It is often accompanied by the symbol of an open jar and the designation of the months, for example 12M. It should not be confused with the date of minimum durability.
How to read the open jar symbol
PAO refers to the period of use of the cosmetic after first opening under appropriate conditions. The notation 12M next to the jar symbol means twelve months, not the number of the calendar month. It's a good idea to note the day you started using it. The EU labeling of cosmetics distinguishes between the date of minimum durability and information after opening; the scope of the obligation depends on the characteristics of the product. PAO does not replace storage instructions or reactions to any visible change in odor, color or consistency.
PAO should not be confused with the date of purchase: a product purchased previously, but properly stored and unopened, has a different history of use than the bottle opened. After opening, the cleanliness of the dispenser and closing the packaging are also important. The term does not justify the use of a cosmetic with clearly changed features.
Meaning and application
The post-opening designation is only relevant to when use was started. If the manufacturer uses them, write the opening date on the packaging or in a note. Check other markings and storage conditions at the same time.
In practice
Don't assume that all products have identical policies. Read the actual symbol and instructions of your own cosmetic. When opening several similar-looking products, keep separate dates rather than treating the entire set as one common bottle.
Do not consider a disturbing change in scent, form or packaging as safe just because the recorded period has not yet passed. PAO does not exempt you from assessing the condition of the product. Do not add water to prolong the convenient use of the leftovers.