How to Check Cosmetic Expiry Dates and Why It Matters

We often pay close attention to the “best by” dates on our food, but many of us overlook the expiration dates in our makeup bags. Using beauty products past their prime isn’t just a matter of poor performance; it can pose genuine risks to your skin and health. Understanding how to identify expired products and knowing when to toss them is a crucial part of any beauty routine.

The Dangers of Expired Beauty Products

Hanging onto that vintage lipstick or years-old mascara might seem harmless, but old cosmetics can become breeding grounds for bacteria.

• Health Hazards: Once preservatives break down, products can harbor bacteria and fungi. This is particularly dangerous for items used near mucous membranes, such as the eyes and lips, potentially leading to sties, pink eye, or cold sores.
• Reduced Effectiveness: Active ingredients, particularly in skincare and sunscreens, degrade over time. An expired SPF will not protect you from UV rays, and an old anti-aging serum likely won’t deliver results.
• Chemical Changes: As formulas oxidize, their chemical structure changes. This can lead to skin irritation, rashes, or contact dermatitis.

How to Decode Expiration Dates

Unlike food, cosmetics don’t always have a clear-cut date stamped on the bottom. Here are the three main ways to determine if a product is still safe to use:

1. The “Period After Opening” (PAO) Symbol This is the most common indicator on beauty packaging. Look for a small icon resembling an open jar with a number and the letter ‘M’ inside (e.g., 6M, 12M). This tells you how many months the product remains stable and safe after you have broken the seal.

2. Hard Expiration Dates Products regulated as drugs (like acne treatments containing salicylic acid or benzoyl peroxide, and all sunscreens) are required by law in many regions to carry a specific expiration date (e.g., EXP 10/2025). If you pass this date, the active ingredients are no longer guaranteed to work.

3. Batch Codes If you can’t find a date or a PAO symbol, look for a batch code printed or stamped on the container. This series of letters and numbers identifies when the product was manufactured. You can enter this code into various online “cosmetic calculators” to determine the production date and estimated shelf life.

General Shelf Life Guidelines

If you’ve lost the packaging or the print has rubbed off, follow these general rules of thumb for common beauty items:

• Mascara & Liquid Eyeliner: 3 to 6 months. (These have the shortest lifespan due to the risk of eye infection.)
• Liquids & Creams (Foundation, Concealer): 12 to 18 months.
• Lip Products: 1 year for glosses and liquids; up to 2 years for traditional bullet lipsticks.
• Powders (Blush, Bronzer, Eyeshadow): 2 to 3 years. (Powders lack the water content that bacteria need to grow, so they last longer.)
• Skincare: 6 to 12 months. (Note: “Clean” or natural beauty products often have fewer preservatives and may expire faster.)

The Sensory Test: Signs It’s Time to Toss

Even if a product hasn’t hit its technical expiration date, you should discard it immediately if you notice:

• Separation: If a cream or liquid has separated into layers that won’t mix back together.
• Odor: A rancid, sour, or “crayons” smell indicates the oils have gone bad.
• Texture Changes: Mascara that is dry and flaky, or lotions that have become lumpy.
• Color Shifts: Oxidation can cause foundations to turn orange or skincare products to darken.

Best Practices for Storage and Hygiene

To ensure your products last as long as possible, proper storage is key.

• Keep it Cool: Heat and humidity accelerate the breakdown of ingredients. Avoid storing makeup on window sills or in steamy bathrooms if possible. A cool, dark drawer is best.
• Seal it Tight: Oxygen is the enemy of cosmetic longevity. Always screw caps on tightly to prevent drying out and oxidation.
• Stop the Spread: Avoid touching products with dirty fingers. Wash your hands before application, and clean your makeup brushes and sponges weekly to prevent introducing bacteria into your products.

Conclusion

Auditing your makeup bag might feel wasteful, but it is an investment in your skin’s health. By learning to read PAO symbols, tracking when you open new items, and recognizing the physical signs of spoilage, you ensure that your beauty routine remains safe and effective. When in doubt, throw it out—your skin will thank you.