Home Cosmetic Science Talk Formulating Color and makeup PAO and Expiration Date

  • PAO and Expiration Date

    Posted by maka on March 10, 2023 at 10:32 am

    Hi Everyone!,

    I hope that someone can enlighten me on this…

    As per uncle Google;

    In cases where the shelf life exceeds 30 months an expiration date
    is not required to be placed on the packing, however a period after
    opening (PAO) is

    My question is; how do I determine the shelf life of makeup? is it by running stability of unopened product over 30 months? If it passes then there is no need for an expiration date (just PAO) and if it fails I need it + I also need PAO? Also, how do I determine PAO? What kind of testing do I need? Is it the same type of testing as for the expiration but using previously opened pieces? or maybe is there a set PAO for certain type of products i.e. 12m for lip glosses?

    Thank you!

    anah replied 1 month, 1 week ago 3 Members · 3 Replies
  • 3 Replies
  • Perry44

    March 10, 2023 at 10:48 am

    Unfortunately, some questions do not have good answers. This is more of a legal / regulatory question than a formulation question.

    The quick answer is yes, stability testing.

    But PAO is pretty much a fairy tale since no one knows how long the product has been around before it was opened. What if the user buys a product, forgets it for 5 years, then tries to use the product? That certainly will have a different expiration point than a product opened 2 weeks after it was made.

    • anah

      January 16, 2024 at 2:16 am

      I have some additional questions.
      lets say a product, PAO date: 6mos, manufactured date: june 2020, expire june 2023. If it’s opened on july 2020, then ideally, it “should” be used by january 2021?

      if it’s opened on june 2023, or past that date, then it is no longer safe to use? should the products be discarded since the testing dictates a june 2023 date? then, how long after opening and using the product is it safe to be used? after the expiration date, the effect of the product and the preservation system is no longer valid, to that date exactly?

      since there’s no way to perform challenge/stability testing once it reaches the consumer’s home, then the PAO is neglible, and wouldn’t the product only be “good” by the expiration date?

  • maka

    March 15, 2023 at 1:08 pm

    Thanks, Perry.

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