Distinguish the dates and symbols
Ireland’s HPRA describes the open-jar PAO symbol as the period after opening during which a cosmetic is considered fit for use. Under the EU framework, products with durability greater than 30 months generally use PAO labeling where relevant. U.S. cosmetic rules do not generally require printed expiry dates.
Read your own product’s label rather than assuming the same format applies everywhere. A batch code identifies a batch; it is not automatically a date you can decode reliably yourself. If the label is unclear, ask the manufacturer with the full code and product details.
Sources: Health Products Regulatory Authority, Ireland · U.S. Food and Drug Administration
Record the opening date when it happens
A PAO clock starts when the product is opened, not when an online order arrives. Add the opening date immediately: a note on the container, a phone record, or a shelf entry all work. If you also keep the purchase date, label it clearly so the two are not confused months later.
For example, a product opened on 26 October 2026 with a 6M symbol reaches its six-month review point on 26 April 2027. Keep the printed expiry information alongside it and follow any earlier applicable limit. A calculated reminder is an organizational aid, not proof that a product remains safe until that day.
- Exact product name and variant.
- Purchase date, when known.
- Opening date, recorded separately.
- Printed expiry or minimum-durability date and PAO wording.
- A photograph of the label and any storage instructions.
Include storage and condition in your review
FDA guidance explains that heat, air, moisture, and contamination can affect cosmetics. Keep containers and applicators clean, avoid sharing makeup, and do not add water to restore a dried product. Store items as directed rather than leaving them in a hot car or direct sunlight.
If a product changes noticeably in smell, color, or texture, stop using it and check the manufacturer’s advice. Do not use a normal appearance as a test that overrides an expired date. A shelf app cannot see contamination inside a container or reconstruct how it has been stored.
Sources: U.S. Food and Drug Administration
Handle an unknown date honestly
If you do not know when a product was opened, mark the date unknown. Do not enter today’s date just to remove a warning, and do not treat the purchase receipt as evidence of first opening. For an uncertain old product, contact the manufacturer or replace it rather than inventing a precise remaining lifespan.
Use the uncertainty to improve the next cycle. Open one replacement at a time and put the opening record where you will actually find it. A small sticker on the bottle can be more reliable than an elaborate inventory that you forget to update.
Treat sunscreen expiry separately
In the United States, sunscreen is regulated as a drug. The FDA advises against using it past its expiry date. If it has no date, consider it expired three years after purchase; discard it if you do not know its age. An open-jar estimate should not replace that guidance.
Keep a sunscreen’s printed date easy to see and review it before travel. Do not rely on an expired bottle for a day outdoors because it still smells normal. Replace it and plan sun protection using clothing and shade as well as correctly applied sunscreen.
Sources: U.S. Food and Drug Administration
Frequently asked questions
What does 12M on an open jar mean?
It indicates a twelve-month period after opening under the product’s intended conditions of use. Keep the opening date and follow the other label instructions too.
Does an unopened cosmetic last forever?
No. Shelf life depends on the formula, storage, and manufacturer’s assessment. Follow printed information and ask the manufacturer when it is unclear.
Can I use a product past its date if it smells normal?
A normal smell does not prove safety or effectiveness. Follow applicable expiry and use-period instructions rather than relying on a sensory check.
What if my sunscreen has no expiry date?
FDA guidance treats undated sunscreen as expired three years after purchase. Discard it when you do not know how old it is.
Sources & further reading
Published by Omnivatis with AI assistance. This guide has not been reviewed by a clinician. The linked references support the educational information; they do not endorse SkinCare AI.
- Shelf Life and Expiration Dating of Cosmetics — U.S. Food and Drug Administration
- Cosmetic products labelling — Health Products Regulatory Authority, Ireland
- Sunscreen: How to Help Protect Your Skin from the Sun — U.S. Food and Drug Administration
SkinCare AI provides general skincare wellness guidance only. Skin scan results are not a medical diagnosis and the app does not treat or prevent any condition. If you have a skin concern, consult a dermatologist or another qualified professional.