| PAO Symbol | Open jar icon with a number (e.g., "12M") = months safe after opening |
| Mascara lifespan | 3 months after opening (General cosmetic industry guidance) |
| Powder products lifespan | 18–24 months after opening |
| Sunscreen shelf life | At least 3 years (FDA requirement for labeled SPF efficacy) (U.S. Food and Drug Administration) |
| Liquid foundation lifespan | 6–12 months after opening |
| Lipstick lifespan | 12–18 months after opening |
What That Little Open-Jar Symbol Actually Means
If you've ever flipped a foundation bottle over and spotted a tiny open jar with a number inside it, you've found the Period After Opening (PAO) date. This symbol — part of international cosmetic labeling standards — tells you how many months a product remains safe and effective after you first open it. A jar marked "12M" means you should use it within 12 months of opening, not within 12 months of purchase.
PAO dates are different from a "best before" or "use by" date, which counts from manufacture and appears on some sealed products like sunscreen or acne treatments. Both matter, but for most everyday makeup, the PAO is the one to watch.
Understanding these labels pairs well with reading ingredient lists more broadly — see our guide on decoding skincare ingredient labels for more label literacy tools.
| PAO Symbol | Open jar icon with a number (e.g., "12M") = months safe after opening |
| Mascara lifespan | 3 months after opening (General cosmetic industry guidance) |
| Powder products lifespan | 18–24 months after opening |
| Sunscreen shelf life | At least 3 years (FDA requirement for labeled SPF efficacy) (U.S. Food and Drug Administration) |
| Liquid foundation lifespan | 6–12 months after opening |
| Lipstick lifespan | 12–18 months after opening |
When Common Makeup Products Go Bad
Not all makeup ages at the same rate. Products that contact moist environments or areas near your eyes carry the highest contamination risk and the shortest lifespans.
Period After Opening (PAO)
A standardized cosmetic label symbol — depicted as an open jar — indicating how many months a product is considered safe and effective after it has been opened for the first time.
Best Before / Use By Date
An expiration date counted from the date of manufacture, not from when you open the product. Common on sunscreens and medicated cosmetics.
Oxidation
A chemical process where exposure to air degrades certain ingredients — such as vitamin C or oils — reducing their effectiveness and sometimes changing their color or smell.
Microbial contamination
The introduction of bacteria, mold, or other microorganisms into a product, typically through repeated use, unclean applicators, or moist storage conditions.
- Mascara and liquid eyeliner: Replace every 3 months. The tube is a warm, dark, damp environment — ideal for bacteria. Pumping the wand introduces more air and speeds up degradation.
- Liquid and cream foundation: Typically lasts 6–12 months after opening. Watch for changes in smell, texture, or color separation as early warning signs.
- Concealer: Similar to foundation — 6–12 months for liquid formulas, up to 24 months for pencil or stick formats kept clean.
- Powder products (blush, bronzer, eyeshadow): Often safe for 18–24 months because their low moisture content limits microbial growth. Clean your brushes regularly to avoid transferring skin oils back into the pan.
- Lipstick and lip gloss: Lipstick typically lasts 12–18 months; glosses with wand applicators, closer to 6–12 months due to the same tube-contamination risk as mascara.
- Sunscreen (SPF products): The FDA requires sunscreens to remain effective for at least 3 years, but check the expiration date — expired SPF products may not protect as labeled.
If you're building a lean kit where products actually get used up on time, our article on minimalist everyday makeup offers a practical starting point.
How to Tell If Something Has Gone Bad
PAO dates are a guideline, not a guarantee. Storage conditions, application habits, and formula type all affect how long a product lasts. Trust your senses alongside the label.
Signs a product has turned:
- A rancid, sour, or noticeably different smell
- Changes in texture — a foundation that has separated or a mascara that has dried and clumped
- Visible mold or discoloration
- Skin irritation or breakouts that weren't an issue before
Products containing active ingredients — like vitamin C serums or retinol — can also oxidize or lose potency before they visually appear spoiled. Yellowing in a vitamin C product, for example, is a common indicator of degradation. For more on how these actives behave, see how skincare ingredients work and degrade.
Fragrance changes are another early clue — and worth paying attention to even for products that aren't expired. Our piece on fragrance in beauty products explains why scent ingredients in cosmetics deserve a closer look.
Practical Habits That Extend Product Life
Buying smart means making products last — within reason. A few simple habits protect your investment without requiring extra spending.
- Write the opening date on the bottom of new products with a marker. Don't rely on memory.
- Keep products away from heat and humidity. A bathroom shelf above a hot shower isn't ideal — a cool, dry drawer or cabinet works better.
- Use clean applicators. Double-dipping dirty fingers into cream products introduces bacteria that shorten product life and can irritate skin.
- Close lids tightly. Air exposure oxidizes formulas and dries out products faster.
These habits matter especially when you're working with a budget — and stretching every dollar wisely is absolutely possible. Our guide on building a beauty routine on a tight budget covers how to prioritize spending without sacrificing results.
This article is for general informational purposes only. If you experience persistent skin irritation or adverse reactions from a cosmetic product, consult a qualified dermatologist or healthcare professional.