Skincare expert Jessica Maxcy of Eight Saints Skincare is urging people to check the small open-jar symbol on sunscreen bottles before using them this summer. The symbol, known as the Period After Opening (PAO), indicates how many months a product remains effective after first being opened.
Understanding the PAO Symbol
The PAO symbol resembles a small open jar with a number followed by an 'M', which stands for months. Common markings include 6M, 12M, or 24M. Maxcy explains: "Before using last summer's sunscreen, find the open-jar symbol. It tells you how long the product should be kept after opening." The countdown begins when the product is first opened, not when it was purchased.
Why It Matters for Sunscreen
Using sunscreen past its PAO date may result in reduced UV protection. Maxcy warns: "Once a sunscreen is well beyond its recommended period after opening, it may become ineffective. That's why checking the PAO symbol is so important, as it helps you avoid relying on SPF that no longer provides the protection you expect."
Other Signs of Deterioration
In addition to the PAO date, consumers should watch for changes in texture or smell. If sunscreen becomes runny, lumpy, grainy, or difficult to spread, it may have degraded. Maxcy advises: "A good sunscreen should feel smooth and consistent every time you use it. If it smells unusual, has separated or doesn't look the way it originally did, I'd replace it rather than rely on it."
Proper Storage Tips
Sunscreen should be stored in a cool, dark place. Avoid leaving it in hot cars, on sunny windowsills, or inside beach bags, as repeated heat exposure can degrade the formula. Maxcy recommends replacing any doubtful sunscreen rather than trying to revive it with moisturiser or water, stating: "It's a small expense compared with spending time outdoors using SPF that may no longer perform as intended."
