Key Takeaways

• The period-after-opening (PAO) symbol is a small open jar printed with a number of months or years, and it comes from EU cosmetics law.

• In the EU, it’s required on products with a minimum durability of more than 30 months, while shorter-lived products carry a “best used before the end of” date instead.

• The US has no matching rule: FDA says no US law or regulation requires cosmetics to have set shelf lives or expiration dates.

• FDA describes how cosmetics break down over time, including emulsions that separate and changes in color, texture, or smell.

How the Period-After-Opening Symbol Works

The symbol is an outline of a jar with its lid lifted, defined in Annex VII of EU Regulation (EC) No 1223/2009. Next to it sits a period in months or years. Article 19 of the regulation says that period is “the period of time after opening for which the product is safe and can be used without any harm to the consumer.”

So the countdown starts on the day you first open the product, not the day you buy it. A jar marked with 12 months is meant to be used within a year of opening.

EU and US Rules Are Not the Same

The PAO symbol is an EU requirement, and it covers one group of products. Under Article 19, a product has to show a date of minimum durability, preceded by a symbol or the words “best used before the end of.” That date isn’t mandatory when a product’s minimum durability is more than 30 months, and those longer-lasting products carry the PAO symbol instead, unless durability after opening isn’t relevant to the product.

The US works differently. FDA’s page on shelf life and expiration dating says there are no US laws or regulations requiring cosmetics to have specific shelf lives or expiration dates on their labels, and it treats working out shelf life as part of the manufacturer’s responsibility. The exception is products that are also drugs, such as moisturizers with SPF labeling, which must be tested for stability and carry expiration dates. If you see the open jar on a product in a US store, it isn’t there because of a US rule.

What Shortens a Product’s Life Once Opened

FDA lists several reasons cosmetics break down over time. Dipping fingers into a jar adds bacteria and fungi, and preservatives can break down. Emulsions, which are mixtures of water and oil, can separate. A humid bathroom may make it easier for microbes to grow, and temperature changes, sunlight, and air can change a product’s color and texture and may affect its smell.

Eye-area products tend to have shorter shelf lives, according to FDA, and it notes that manufacturers usually recommend discarding mascara two to four months after purchase. Keeping fewer jars open at once can make those windows easier to stick to. A settled skincare routine order shows what you actually reach for, and a simple skincare routine keeps the shelf short.

Frequently Asked Questions

Is It Safe to Use Skincare Past Its PAO Date?

The PAO number is the window the label covers. FDA notes that preservatives can break down over time, so once that window has passed, replacing the product is the cautious choice, especially if it looks, feels, or smells different.

Does Unopened Skincare Expire Too?

In the EU, a product expected to last 30 months or less has to carry a “best used before the end of” date, opened or not. Storage counts as well: FDA advises keeping cosmetics out of heat, such as a hot car, because heat can make preservatives break down.

Does Sharing Products Change How Long They Last?

It can. FDA advises against sharing makeup, and it says testers at cosmetic counters are even more likely to become contaminated than the same products at home.