If you’ve just found a bottle of sunscreen that you had purchased in anticipation of Y2K then it’s probably not great idea to use it. After all, while sunscreen can keep for a while, a quarter of a century is a little or maybe a lot too long. The effectiveness of sunscreen will at some point deteriorate over time and eventually no longer provide adequate protection for your skin against the ultraviolet rays from the sun. That’s why you shouldn’t be using sunscreen that you’ve found in a time capsule. The question then is what do you do if you’ve got a container of sunscreen that’s been stored on your shelf or in your Kardashian hope chest?
The first thing you should do is look for an expiration date on the container. Since there’s no mandate from the U.S. Food and Drug Administration (FDA) to put such a date on sunscreen containers, you could be looking for a long time. However, if you do find an expiration date and today’s date is already past that date then it’s better to get rid of the sunscreen. And get rid of it doesn’t mean have your partner use it. Get rid of means discard it so no one will accidentally use it. You don’t want anyone to falsely believe that they are protected from the UV radiation than can damage their skin and lead to different types of skin cancer.
When you can’t find an expiration date, you might assume that the sunscreen is good for up to three years after the purchase date. That’s because the FDA does require manufacturers to make sure that their sunscreen stays at its original strength for at least three years. “At least” means that in theory the sunscreen could stay effective for many years longer. But it’s not a good idea to play sunburn roulette here. Once you get beyond the three year mark and there’s not expiration date, all bets are off.
All of the above assumes that the sunscreen was kept in reasonable storage conditions. While opening the bottle won’t accelerate the deterioration of the sunscreen within, heat and sunlight exposure can. Therefore, if someone says, “You can use this sunscreen, although I did blowtorch the container once a week for the past year,” you may want to shell out the extra bucks to get a new bottle. It may not be obvious if the sunscreen has been changed by the surroundings. It’s not as if sunscreen will automatically start looking like spaghetti sauce when it’s been changed. So, if the sunscreen has been left outside, in the trunk of a car or on top of a brick pizza oven for while, it’s better to discard it.
Of course, if the sunscreen has changed color, texture or smell then don’t use it regardless of when its expiration date may be and how safely it may have been stored. For example, if your sunscreen smells like fish—assuming that you didn’t buy that special Sushi Sunscreen—then something fishy may have happened.
Now, unless you are in the habit of hoarding crates of sunscreen bottles, having a container that you’ve kept for a long period of time may be a sign that you aren’t using enough sunscreen. Typically each time you apply sunscreen to your face and body, you should be using at least a shot glass-worth, which is about an ounce or 30 milliliters. In fact, you may be using more since using too much sunscreen is not a problem unless you find yourself sliding all over the place because you’ve become too slippery. When you are depleting the container by a shot each time, you will probably shoot through the container within a year.
In general, it’s better to err on the side of caution when applying sunscreen and buying new containers of the stuff. Since you don’t necessarily have to take out a loan to buy another bottle of sunscreen, you don’t want to be gambling with something that may or may not work.
