Shelf life, period-after-opening (PAO) and batch codes answer three different questions: how long the sealed product stays within specification, how long it stays safe once the consumer opens it, and which production run a given unit came from. Only the third is genuinely a manufacturing record — the first two are conclusions drawn from your own stability and preservative data, and the legal responsibility for both sits with the brand owner whose name is on the pack, not with the factory that filled it. Before you approve artwork, ask your manufacturer in writing which number they are proposing, what data supports it, and how long they will retain the batch records and samples behind it.
Key takeaways
- Your factory proposes the shelf life; you own it. The date on the pack is a claim made by the brand named on the label, and it has to be supported by stability, preservative-efficacy and packaging-compatibility data on file — not by the factory’s habit of writing “36 months” on everything.
- Shelf life and PAO are not interchangeable. Under EU and UK rules a product that keeps for 30 months or less must carry a minimum durability date; one that keeps longer carries the open-jar PAO symbol instead. Printing both, or the wrong one, is a re-print.
- The batch code is the only thing that makes a problem containable. Without a code that maps to a filling date, a formula version and a raw-material lot, a single complaint becomes a whole-market question rather than a one-batch answer.
- Retention samples and batch records live at the factory by default. If your supply agreement does not say how long they are kept and that you can call for them, they can be discarded on the factory’s own schedule — usually right when you need them.
- Agree recall mechanics before you need them. Who notifies the authority, who holds the distribution list, who pays for uplift and replacement, and how fast the factory must respond are contract questions, not crisis questions.
What do shelf life, minimum durability and PAO actually mean?
Shelf life is the period during which an unopened product, stored normally, stays within the specification it was approved against — appearance, odour, colour, pH, viscosity, active content and microbiological quality. Minimum durability date is the regulatory expression of that period on the pack. Period-after-opening (PAO) is a separate figure: the number of months the product stays fit for use after the consumer first opens it, when preservation and pack design have to cope with repeated contamination. They are derived from overlapping data but they answer different questions, and a factory quoting one when you asked for the other is a common source of artwork rework.
A fourth term gets tangled in with these. “Expiry date” is drug language. In most cosmetic markets the correct phrase is a minimum durability date — the point after which the manufacturer no longer guarantees the specification, not a cliff after which the product becomes dangerous. Several ASEAN national guidelines do use expiry or manufacturing-date wording on cosmetic packs, which is why exporting the same artwork into a second region so often forces a change. If you are planning that step, the sequencing matters more than the wording; see our guide to expanding a private-label brand into the EU, UK and US.
| Term | What it actually means | Who sets it | Where it appears | The misunderstanding we see most |
|---|---|---|---|---|
| Shelf life | How long the sealed product stays within its approved specification under normal storage | Brand owner, on the basis of stability and preservative data generated for that formula in that pack | Specification sheet, safety file, purchase order | Treating it as a property of the formula alone — it is a property of the formula in a specific pack |
| Minimum durability date | The pack-facing expression of shelf life, as “best used before end of” plus a date | Brand owner; printed or coded by the filler | Outer pack and, in most cases, the immediate container | Assuming it is required on every product — in the EU and UK it is required only where durability is 30 months or less |
| Period after opening (PAO) | Months of safe use after first opening, shown by the open-jar symbol and a figure such as 12M | Brand owner, supported by preservative-efficacy testing and pack type | Printed as a symbol on the pack | Copying “12M” from a competitor. The number has to match your preservation data and your closure type |
| Batch / lot code | A unique reference identifying one production run | Manufacturer, to a scheme you have agreed | Coded on pack, plus every record behind it | Accepting a code you cannot decode. If only the factory can read it, you cannot investigate anything yourself |
| Retention sample | Units set aside from each batch and stored so the batch can be re-examined later | Manufacturer, for a retention period you should specify | Nowhere on the pack — it exists only if someone agreed to keep it | Assuming it exists. Retention is normal GMP practice but the duration is not standardised |
Who decides your product’s shelf life, and how is the date set?
Nobody issues you a shelf life. It is a conclusion you reach from evidence, and in a private-label project the evidence is generated by the manufacturer or a contract laboratory and interpreted for you. In practice four inputs feed the decision: real-time and accelerated stability data, preservative-efficacy (challenge) testing, packaging-compatibility results in the actual production pack, and a microbiological risk assessment of the formula type. Our walkthrough of how stability testing is run covers the first of those, and the wider pre-production test panel shows how they are sequenced before a first batch.
Accelerated stability — typically several weeks at elevated temperature, often around 40°C to 45°C, with freeze-thaw and light cycles alongside — is a screening tool. It tells you quickly whether a formula is going to separate, discolour or drift in pH. It is widely used in the industry as a rough proxy for two to three years of ambient shelf life, but that conversion is a rule of thumb rather than a validated equivalence, and no standard endorses it. A 36-month claim supported only by three months at 40°C is a claim your safety assessor may not accept and a claim you would struggle to defend. Real-time data at ambient conditions, running in parallel and reported as it accumulates, is what actually supports a long durability figure.
The PAO figure comes from a different place. It rests on preservative-efficacy testing against the criteria in ISO 11930, on whether the formula falls into the low-risk category described in ISO 29621, and heavily on the closure: an airless pump, a tube and an open jar of the same cream do not deserve the same number. This is one of the reasons the pack format you choose is a safety decision and not only a cost or aesthetic one. If you switch from a pump to a jar late in a project, the PAO you agreed earlier no longer follows automatically.
What this means commercially is that shelf life should be a line in the specification you sign off, with the supporting data referenced next to it. If the number arrives verbally, or appears for the first time on a proof of the artwork, it has not been set — it has been assumed.
What is a batch code, and what does it have to let you do?
A batch code is a unique reference for one production run, and its only real job is to let a specific unit in a consumer’s hand be connected back to everything that went into it. That means a code is adequate when it resolves, through the factory’s records, to the filling date, the bulk batch, the formula and specification version, the raw-material lots used, the packaging component lots, the release results and the quantity shipped to each customer. A code that resolves only to “a week in March” is a label element, not a traceability tool.
Codes come in several shapes. Some manufacturers use a plain sequential number; some encode the date, line and shift; some use Julian dating, where 24 156 reads as the 156th day of 2024. Any of these is fine. What is not fine is a scheme you cannot decode without emailing the factory. Ask for the key in writing and keep it with your specification, because the moment you actually need it — a customer photograph, a retailer query, a complaint — you will want to know within minutes whether two reports involve the same batch.
If you sell through retail or distribution, the code usually also has to travel in machine-readable form. The GS1 General Specifications define the application identifiers used for this on GS1-128 and DataMatrix codes, including (10) for batch or lot number and (17) for expiration date; distributors and larger retailers increasingly expect these on the case, and sometimes on the unit. Decide this before plates are cut, because it changes the artwork — our walkthrough of getting artwork print-ready covers where variable data has to be left clear for coding.
One practical detail that catches brands out repeatedly: where the code is applied. Inkjet on the crimp of a tube, laser on the base of a bottle, hot foil on a carton and a pre-printed label all behave differently. Codes applied to a component that the consumer discards — an outer carton, a shrink sleeve — are useless in a complaint six months later. Insist that the batch code and durability marking appear on the immediate container as well as any outer, and confirm the marking survives handling; the packaging and label requirements checklist lists the other elements that have to share that space.
Which markings does each market actually require?
The requirement differs by market, and the differences are the kind that force a second print run rather than a reformulation. The table below covers the four regions private-label brands ask about most. Treat it as a planning map and confirm the current position for your specific product against the primary sources listed at the end, because national guidance within ASEAN in particular varies.
| Market | Durability marking | PAO | Batch identification | Practical consequence for your artwork |
|---|---|---|---|---|
| European Union | Date of minimum durability required where durability is 30 months or less, in the “best used before end of” form | Required instead, using the open-jar symbol, where durability exceeds 30 months — except where the concept does not apply, such as single-use or sealed products with no risk of deterioration | Batch number, or a reference identifying the product, required | You must decide which of the two markings applies before artwork, and you cannot decide it without stability data |
| Great Britain | Same structure, carried into UK law by the Cosmetic Products Enforcement Regulations 2013 | Same open-jar approach | Batch number required | Same markings, but a UK Responsible Person address must fit alongside them |
| ASEAN member states | Labelling under the ASEAN Cosmetic Directive includes a manufacturing or expiry date; national guidance decides the exact form | Not the primary mechanism in most member states | Batch number required | Artwork built for the EU often needs a date field added rather than a symbol, so leave the space |
| United States | No FDA regulation requires an expiration date on a cosmetic; determining shelf life is the manufacturer’s responsibility. An expiration date, once printed, must be supported | Not mandated | Not federally mandated for cosmetics, though records under MoCRA and ordinary traceability practice make coding necessary | The trap is category: a sunscreen is an over-the-counter drug in the US and OTC drug products are subject to expiration-dating requirements |
Two things follow from that table. First, the same jar can legitimately carry different markings in different regions, so a single global artwork is often a false economy. Second, the US position is not permission to skip the work — FDA is explicit that determining shelf life is the manufacturer’s responsibility, and any date you do print becomes a claim you have to stand behind. If your artwork is still in progress, our tutorial on setting up a compliant cosmetic label sets out the rest of the mandatory elements.
What does traceability mean in practice, and what does your OEM owe you?
Traceability means that from any finished unit you can move backwards to every input and forwards to every customer who received that batch. In an OEM arrangement almost all of the underlying records sit with the factory, which is normal — but it means your ability to investigate anything depends entirely on what your agreement says you can call for, and how long those records survive. Cosmetics GMP under ISO 22716 covers documentation, batch records, retention samples and the handling of complaints and recalls; what it does not do is set the retention period for your particular product or give you an automatic right of access. That comes from your contract. Our overview of what GMP certification actually covers is worth reading alongside this if you are relying on a certificate as assurance.
| Record | Who normally holds it | What it lets you do | What to put in the supply agreement | The objection you should expect |
|---|---|---|---|---|
| Batch manufacturing record | Manufacturer | Reconstruct exactly how one run was made, including deviations | A right to inspect on request, and retention for shelf life plus a defined margin | “That is internal documentation” — agree a redacted summary format up front instead of arguing later |
| Certificate of analysis per batch | Manufacturer, issued to you | Show the batch met specification at release | Issued with every shipment, not on request; specification version referenced on the certificate | Certificates arriving weeks after the goods, or with no batch code on them |
| Raw material and packaging lot traceability | Manufacturer | Narrow an ingredient or component problem to the affected batches only | Obligation to maintain lot-level links and to disclose affected batches within a stated number of days | “We buy from several suppliers” — that is the reason to require it, not to waive it |
| Retention samples | Manufacturer | Re-test a disputed batch against the original article rather than argue from photographs | Quantity per batch, storage conditions and a retention period you name — shelf life plus twelve months is a common ask | Storage space. Expect a small cost line; it is cheaper than an unresolvable dispute |
| Distribution records | Shared — factory to you, you onwards | Know precisely who received which batch | Batch codes stated on every despatch document | Consolidated shipments with no batch breakdown, which makes a targeted withdrawal impossible |
| Stability and challenge test reports | Manufacturer or laboratory | Support the durability and PAO figures if they are questioned | Copies supplied to you, in your name where the laboratory allows | Reports referenced but never sent — ask for the document, not the conclusion |
Read that table as a negotiating list rather than a wish list. Every line is ordinary in a well-run factory, and the cost of agreeing them at contract stage is close to zero; the cost of asking for them mid-incident is a supplier who has no obligation to help. Our collection of real OEM contract clauses shows how these obligations are usually worded, and the note on reading a specification sheet and certificate of analysis covers what a useful certificate should contain. If you are still choosing between suppliers, the manufacturer directory is the right place to start a shortlist you can put these questions to.
What happens in a recall, and what should you have agreed first?
Two words get used loosely and mean different things. A withdrawal removes product from the supply chain before it reaches consumers; a recall retrieves product that has already reached them. Withdrawals are quiet and comparatively cheap. Recalls involve notifying an authority, communicating publicly, and reconciling what went out against what comes back — and in the EU that means alerting the market surveillance authority, while in the United States MoCRA gave FDA the power to order a mandatory recall where a product is likely to cause serious adverse consequences, in addition to the adverse-event records a responsible person must now keep.
The variable that decides how bad it gets is scope. If your batch coding and distribution records are good, a contaminated bulk lot is a defined number of units, a defined set of customers and a defined cost. If they are not, you are choosing between recalling everything and defending a decision not to. That is the whole commercial argument for taking codes and records seriously in a project where nothing has gone wrong yet, and it is why quality control practice at the factory is worth auditing before your first order rather than after your first complaint.
Six questions to put to a manufacturer before you place a first order.
- What shelf life are you proposing for this formula in this pack, and which stability, challenge and compatibility reports support it? Ask for the reports, not a number.
- What is your batch coding scheme, and can you give me the key so I can decode it myself?
- Where is the code applied, and does it appear on the immediate container as well as the outer?
- How many retention samples do you keep per batch, under what conditions, and for how long?
- If I report a suspected defect, how quickly will you confirm which batches and which customers are affected?
- In a withdrawal or recall, who notifies the authority, who bears the cost of uplift and replacement, and what is your response time commitment?
Red flags. A shelf life quoted before any testing has been done. A batch code you are told not to worry about. Retention samples described as unnecessary “because we have never had a problem”. Certificates of analysis that carry no batch code or no specification version. A refusal to put record-retention periods in writing. Any of these is survivable on its own; together they describe a supplier who has never had to answer for a batch, which is a different risk profile from one who has.
Frequently asked questions
Is a period-after-opening the same as a shelf life?
No. Shelf life describes the sealed product on a shelf; PAO describes the opened product in a bathroom, where it is exposed to fingers, water and air. A product can have a three-year shelf life and a six-month PAO, and the two figures rest on different evidence — stability data for the first, preservative-efficacy results and closure type for the second. Under EU and UK rules the two markings are alternatives rather than a pair: a durability date where the product keeps 30 months or less, the open-jar symbol where it keeps longer.
Can my manufacturer just tell me the shelf life?
They can propose one, and a good manufacturer’s proposal is informed. But the durability claim on the pack belongs to the brand named on the label, and it has to be supported by data held in your product file. Ask which reports the figure comes from and get copies. If the answer is that the formula is a standard base they have supplied for years, that is useful background but it is not evidence for your pack, your fragrance and your fill.
How long should retention samples be kept?
There is no single mandated period for cosmetics, which is exactly why it needs to be in your agreement rather than left to custom. Shelf life plus twelve months is a common commercial ask, because it keeps a physical reference available for the whole period a consumer might reasonably still be using the product and a little beyond. Specify quantity, storage conditions and who bears the cost, and confirm the factory will not discard samples on a change of ownership or contract termination.
What is the difference between a product withdrawal and a recall?
A withdrawal takes product out of the supply chain before consumers have it; a recall retrieves product already sold. Recalls carry authority notification, public communication and reconciliation obligations that withdrawals usually do not, and they are far more expensive. The practical implication is that speed matters: the faster your factory can tell you exactly which batches went where, the more likely a problem stays a withdrawal. Agree that response time in the contract, expressed in days.
Do I need an expiry date if I only sell in the United States?
FDA does not require expiration dating on cosmetics, and states plainly that determining shelf life is the manufacturer’s responsibility. That is not the same as it not mattering. Any date you print becomes a supportable claim, retailers and marketplaces frequently ask for one, a sunscreen sold in the US is regulated as an over-the-counter drug and subject to drug expiration-dating rules, and the moment you export the same stock to the EU, UK or an ASEAN market the marking becomes mandatory in some form. Set the shelf life properly even where the label does not force you to.
Sources and limitations
Regulatory positions here are drawn from primary sources. For the EU, the European Commission’s cosmetics legislation portal for Regulation (EC) No 1223/2009, including the labelling requirements for minimum durability, period after opening and batch number, and the CosIng database for ingredient status. For Great Britain, the Cosmetic Products Enforcement Regulations 2013. For ASEAN, the Health Sciences Authority of Singapore’s summary of the ASEAN Cosmetic Directive. For the United States, FDA’s pages on shelf life and expiration dating of cosmetics, the Cosmetics Labeling Guide, the Modernization of Cosmetics Regulation Act of 2022 and cosmetics compliance and enforcement. Standards referenced are ISO 22716 for cosmetics good manufacturing practice, ISO 11930 for evaluating antimicrobial protection and ISO 29621 for products considered low risk microbiologically. Machine-readable batch and date encoding follows the GS1 General Specifications. The safety file that carries the shelf-life reasoning in the EU and UK is described in our explainer on the cosmetic product safety report.
Limitations. The retention periods, response times and testing durations described here are ordinary commercial practice observed in private-label projects, not surveyed data or regulatory minimums, and they vary by product category, market and supplier. The market comparison is summarised at a level useful for planning artwork and contracts; national guidance within ASEAN differs between member states, and requirements change. We did not audit any manufacturer, laboratory or testing provider in preparing this article. Confirm the position for your own product against the primary sources linked above, or with a qualified safety assessor or regulatory adviser in your destination market, before approving artwork or signing a supply agreement. Last reviewed 25 August 2026.
This article is general information for brand owners and sourcing teams, not legal, regulatory or toxicological advice. Shelf-life, labelling and traceability obligations differ by product category, claim and jurisdiction and change over time — confirm your own product’s position with the relevant authority or a qualified adviser before placing it on any market.