Why the expiry date on a cosmetic is the output of laboratory evidence rather than a number a brand chooses, and what Malaysian, EU and US labelling rules actually require.
Disclosure: This article is published by ORIZI Group and may refer to our own manufacturing experience, services and capabilities. External factual claims are supported by cited sources.
Key takeaways
- An expiry date is a conclusion drawn from three data sets: stability, packaging compatibility and preservative efficacy.
- Accelerated testing estimates a shelf life in weeks; real-time testing under normal storage confirms it.
- Malaysia (NPRA) requires a manufacturing date or an expiry date, and makes the expiry date mandatory when minimum durability is under 30 months.
- The open-jar PAO symbol (“12M”) is required in the EU for products lasting more than 30 months; it is optional in Malaysia.
- Changing the formula, pack material or closure can reopen the testing.
What this guide covers
This guide covers cosmetics notified in Malaysia under the ASEAN Cosmetic Directive and regulated by the National Pharmaceutical Regulatory Agency (NPRA): skincare, hair, body, fragrance and colour cosmetics. Medicines, supplements and medical devices follow their own rules.
Shelf life (minimum durability) is the period during which an unopened cosmetic, stored as directed, keeps its original function and stays safe. Stability testing measures how appearance, odour, pH, viscosity and active content change over time and temperature. A challenge test is a preservative efficacy test in which the product is deliberately contaminated to prove the preservative system controls microorganisms. PAO (period after opening) is the number of months a product stays safe to use once opened.
What decides how long a cosmetic lasts?
A cosmetic fails in four ways, and a shelf-life study watches all four. The US Food and Drug Administration lists the everyday causes: microorganisms from fingers and applicators, preservatives breaking down, emulsions separating, products drying out, and colour and texture changes from heat, sunlight and air (FDA: shelf life and expiration dating of cosmetics).
| Failure type | What you see | Usual cause |
|---|---|---|
| Physical | Separation, thinning, grittiness, sweating sticks | Emulsifier or thickener system drifting with heat and time |
| Chemical | Colour shift, rancid odour, pH drift, active loss | Oxidation, light, ingredient interactions |
| Microbiological | Mould, gas, odour, slime; often invisible at first | Preservative system too weak for in-use contamination |
| Packaging | Weight loss, leaking pumps, cracked or stained plastic | Volatile loss through the pack wall, migration, incompatible materials |
Which stability tests set a cosmetic’s expiry date?
Accelerated stability testing is a predictive study that stores samples at raised temperatures, typically for about 90 days, to estimate an expiry date that real-time data must later confirm. Brazil’s health regulator ANVISA publishes one of the few regulator-issued stability guides for cosmetics (ANVISA Cosmetic Products Stability Guide); the international reference is ISO/TR 18811:2018, which describes the approach without fixing conditions (ISO/TR 18811:2018 via BSI).
| Study | Question it answers | Typical conditions (ANVISA guide) |
|---|---|---|
| Accelerated stability | How fast will this formula change? | Ovens at 37, 40, 45 or 50 °C (±2 °C), 5 °C, and −5 or −10 °C; usually 90 days, checked at day 0, 1, 7, 15, 30, 60 and 90 |
| Freeze-thaw cycling | Will it survive transport and seasonal swings? | Alternating 24-hour periods, e.g. 45 °C and −5 °C for 12 days (6 cycles) |
| Light exposure | Will colour, odour or actives degrade? | Sunlight through glass or xenon lamps |
| Real-time (shelf) study | Does the estimate hold under normal storage? | Room temperature, checked up to the claimed expiry date |
| Packaging compatibility | Does the formula behave in the final pack? | Final pack tested alongside neutral glass |
The accelerated result remains an estimate: heat speeds some changes, such as oxidation, far more than others, and can cause failures, such as a wax base melting, that never happen on a shelf. That is why the real-time study keeps running after launch.
How does packaging compatibility change shelf life?
Packaging compatibility testing checks that the formula and its container do not change each other over the shelf life. The same cream can pass in glass and fail in a thin plastic tube, so the test uses the pack the customer will buy.
- Weight loss: water and volatiles can escape through some plastics.
- Migration: preservatives and fragrance can move into a plastic wall, leaving less in the product.
- Material stress: some oils and fragrances craze or stain plastics; some formulas corrode metal tubes and cans.
- Function: pumps, droppers and airless systems must still dispense at the end of the shelf life.
Pack choice is also part of preservation: an airless pump exposes the formula far less than an open jar, which is why our container and packaging team is involved before the stability study starts.
What does a preservative efficacy (challenge) test prove?
A challenge test proves that the preservative system can control contamination introduced during use. ISO 11930:2019 is the recognised method for cosmetics: the product is inoculated with bacteria, a yeast and a mould, and surviving counts are measured at set intervals up to 28 days against defined reduction criteria (ISO 11930:2019 via BSI). Products such as anhydrous oils and high-alcohol perfumes can be microbiologically low-risk by design, and ISO 29621 sets out how to document that assessment rather than assume it (ISO 29621:2017 via BSI).
NPRA’s safety-assessment guideline names stability studies “to evaluate shelf life, preservative effectiveness (challenge test), compatibility of the product and the packaging” as safety measures (NPRA Annex I Part 6). Its microbial limit is a total viable aerobic count of no more than 1,000 cfu/g (500 cfu/g for products for children under three, the eye area and mucous membranes), with named pathogens absent in 0.1 g (NPRA Annex I Part 14). Lightly preserved formulas are where this matters most, as explained in why a clean and natural brief becomes a preservation problem first.
How should the expiry date and PAO appear on the label?
| Market | What the label must show | Source |
|---|---|---|
| Malaysia (ASEAN framework) | Manufacturing date or expiry date (month/year), preceded by “expiry date” or “best before”. Expiry date mandatory when minimum durability is less than 30 months. No PAO requirement. | NPRA Annex I Part 7 |
| European Union | Date of minimum durability (hourglass symbol or “best used before the end of”) unless durability exceeds 30 months; then the PAO open-jar symbol, except where durability after opening is not relevant. | Regulation (EC) No 1223/2009, Article 19(1)(c), Annex VII (European Commission) |
| United States | No law requires an expiration date on a cosmetic; the manufacturer determines shelf life. Drugs and cosmetic-drug products must carry one. | FDA |
The PAO symbol is an open jar with a number and the letter M, such as 6M or 12M: the months of safe use after first opening. EU law prescribes the symbol but not a test method, so the number is set from the challenge-test result, how much the pack exposes the product and how it is used. For the documents importers ask for, see cosmetic export documents explained.
How long does stability work take before a launch?
- Formula screening (days to weeks): short, harsh tests on lab batches remove unstable candidates.
- Accelerated study (about 90 days): the chosen formula in neutral glass and the final pack.
- Challenge test (28 days of sampling plus laboratory lead time): on the final formula in the final pack.
- Expiry estimate and PIF: NPRA’s Product Information File guideline expects a Product Stability Summary Report, “the stability testing data and report or stability assessment to support the expiry date” (NPRA Annex I Part 13).
- Real-time confirmation: room-temperature samples are checked until the claimed expiry date.
ORIZI perspective: what changes reopen the data
Based on ORIZI Group’s manufacturing experience, expiry dates go wrong more often in the project plan than in the laboratory. A formula is approved, the stability study starts, and then the fragrance, bottle supplier or pump changes, so part of the data no longer describes the product being filled. ANVISA’s guide notes the same trigger: accelerated testing can be repeated whenever ingredients, process or the packaging in contact with the product change significantly. We use this matrix at the brief stage so changes happen before the clock starts.
| What changes | What it reopens |
|---|---|
| Any formula ingredient, including fragrance | Stability study; challenge test if preservation could be affected |
| Pack material or pack supplier | Compatibility and stability in the new pack |
| Closure type (jar to airless, cap to dropper) | Challenge-test relevance and the PAO you can claim |
| Fill size, same material | Usually a compatibility and weight-loss check |
| New export market | Date format, storage statement and documents for that market |
For scope: Dr Orizi (M) Sdn. Bhd., ORIZI Group’s cosmetics factory, operates under NPRA cosmetic GMP (since 2024) and ISO 22716 (since 2022). Routine quality checks run in our own QC lab; challenge tests and stability and packaging-compatibility studies run at ISO/IEC 17025-accredited laboratories. The limit we hold to: the date on the label follows the data, and a real-time result can shorten a planned shelf life. How NPRA GMP and ISO 22716 relate is covered in GMP by NPRA vs ISO 22716.
Risks, limitations and common mistakes
- Testing only in glass. Glass is the reference, not the product.
- Treating accelerated data as final. It is an estimate until real-time data confirms it.
- Changing the fragrance late. Fragrance affects colour, odour, viscosity and sometimes preservation.
- Borrowing a PAO. A sister product’s 12M with a different pack or preservative system is not evidence.
- Forgetting drug-category rules. Sun-protection products are cosmetic-drug products in the US (FDA: is it a cosmetic, a drug, or both?) and need an expiry date; any formula change means retesting, as in why changing a sunscreen formula means testing the SPF again.
FAQ
How long are skincare products good for unopened?
An unopened skincare product is good until the expiry date printed on it. In Malaysia an expiry date is mandatory when durability is under 30 months, so a product showing only a manufacturing date is expected to last at least 30 months from that date when stored as directed.
Can shampoo and other hair care products expire?
Yes. Shampoos and conditioners are water-based and preserved, so they can separate, thin, change odour or lose preservative strength. Their shelf life is set by the same stability and challenge testing as skincare.
Does perfume have an expiry date?
Perfume changes with time even though high-alcohol perfume is microbiologically low-risk: fragrance materials oxidise, so colour and scent drift with heat and light. Where tested durability exceeds 30 months, a Malaysian label may show a manufacturing date instead of an expiry date.
What does 12M on a cosmetic mean?
12M is the period-after-opening (PAO) symbol: use the product within 12 months of first opening. It is required in the EU for products lasting more than 30 months and optional in Malaysia.
Do I need stability data before NPRA notification?
The stability summary is part of the Product Information File that the cosmetic notification holder must keep and make available to NPRA, so the data or a documented stability assessment should support the expiry date before sale. ORIZI’s regulatory affairs team supports PIF preparation.
Sources & references
- NPRA Annex I Part 7 — Cosmetic Labeling Requirements — date rules, 30-month threshold
- NPRA Annex I Part 13 — Product Information File — stability summary report
- NPRA Annex I Part 6 — Safety Assessment — stability, challenge and compatibility studies
- NPRA Annex I Part 14 — Microbiological Test Limits — microbial limits
- ANVISA, Cosmetic Products Stability Guide — test conditions and packaging compatibility
- ISO/TR 18811:2018 (BSI listing) — stability testing guidance
- ISO 11930:2019 (BSI listing) — challenge test
- ISO 29621:2017 (BSI listing) — low-risk products
- European Commission — cosmetics legislation — Regulation (EC) No 1223/2009, Article 19 and Annex VII
- US FDA — Shelf Life and Expiration Dating of Cosmetics — US position; causes of deterioration
- US FDA — Is It a Cosmetic, a Drug, or Both? — cosmetic-drug products
Update history: October 2026 — first published.
Planning a new formula or a pack change? See what can be tested on our product testing page, or send a short project brief and we will map the stability, compatibility and challenge-test plan for your product and market.
