Minimum Durability Dates on EU Cosmetic Labels

Two symbols on an EU cosmetic label look similar and get confused constantly: the little hourglass and the open jar with a number inside. They answer different questions, and mixing them up is one of the more common labeling mistakes we see from brands moving into the EU market.

The hourglass is a date, not a duration

Under Regulation (EC) No 1223/2009, a product has to carry a minimum durability date if its shelf life, kept under proper conditions, is 30 months or less. This is the "best used by" concept: an actual date or a clear reference to where the date is printed (like "see cap" or "see base of tube"). The hourglass symbol is the shorthand for this, and it's paired with a specific day/month or month/year depending on how precise the claim is.

If a product's stability supports more than 30 months unopened, you don't need this date at all. That's why you'll see it on lip balms and some liquid foundations but not on, say, a bar of soap with a long, well-documented shelf life.

PAO answers a different question

The Period After Opening symbol, the open jar with "12M" or "6M" inside, tells the user how long the product stays safe and effective once it's been opened and exposed to air, fingers, and daylight. This is required when the product is stable for more than 30 months unopened, precisely because the durability date doesn't apply and consumers still need guidance.

Products that are used once and thrown away, like single-use sheet masks or sachets, generally don't need a PAO mark, since there's no "after opening" period to speak of.

Where the numbers actually come from

Neither symbol is a guess. Both trace back to stability testing that's part of the Cosmetic Product Safety Report, and both are referenced in the Product Information File that the Responsible Person has to maintain. Typical stability work includes:

• Real-time storage studies at room temperature over the claimed period
• Accelerated aging, often at elevated temperature and humidity, to model degradation faster than real time
• Microbiological challenge testing (a preservative efficacy test) to confirm the formula resists contamination through repeated use
• Compatibility checks between the formula and its packaging, since some actives degrade faster in clear glass or certain plastics than others

A safety assessor reviews this data before signing off on the CPSR, and that same data is what justifies whichever symbol, or combination, ends up on the pack.

A quick side-by-side

Symbol	What it means	When it's required	Backed by
Hourglass with date	Minimum durability date, "use by"	Shelf life of 30 months or less	Real-time and accelerated stability data
Open jar (PAO)	Months safe to use after opening	Shelf life over 30 months	Stability plus preservative challenge testing
Neither	N/A	Single-use, non-reusable packaging	Rationale documented in the PIF

Common mistakes worth avoiding

A few patterns show up again and again in EU-bound labels:

1. Putting a PAO jar on a product that actually needs a durability date instead, because someone assumed PAO is the default.
2. Guessing a PAO period (12M is common as a default) without stability data to support it. Regulators and safety assessors expect a documented basis, not a round number picked for convenience.
3. Forgetting that reformulating a product, even a small preservative swap, can change the PAO or durability figure. The number belongs to that specific formula, not the product name.
4. Not updating the CPNP notification and PIF when the durability period changes after a reformulation.

If you're building this for the first time

If you're a smaller brand without an in-house regulatory team, the honest starting point is getting real stability and preservative efficacy testing done by a lab, then having a qualified safety assessor translate that into the correct symbol and figure for your label. This isn't something to eyeball from a competitor's product, since their formula, packaging, and testing are not yours.

Cosmetic Comply is built around the notification side of this process rather than lab testing itself, matching ingredients to INCI and CAS and screening them, but it's worth knowing where shelf life fits in the bigger EU compliance picture before your product ships. Getting the symbol right the first time saves you a relabel later, which is a cost every small brand would rather skip.