The hot, hazy days of summer have returned.
You might love that, but your skin certainly doesn’t. That’s because the ultraviolet A (UVA) and ultraviolet B (UVB) rays of the sun can cause sunburns, premature aging, and even cancer.
This is where the need for SPF protection comes in. If you’ve ever found yourself with only an old bottle of sunscreen lying around, you might have wondered: Does sunscreen expire?
This article shines a light on this very important question.
The Food and Drug Administration (FDA) requires that all sunscreens remain at their full strength for 3 years.
According to NYC dermatologist Dr. Hadley King, physical (or mineral) sunscreens are more stable compared with chemical sunscreens, and therefore usually have longer shelf lives.
The main difference between the two is that physical sunscreen sits on top of the skin to reflect UVA and UVB rays, whereas chemical sunscreens convert UV rays into heat.
“Chemical sunscreens consist of innately unstable molecules, but in the past few years manufacturers have started adding stabilizers like octocrylene,” explains King.
Physical sunscreens, on the other hand, primarily contain zinc oxide and titanium dioxide.
You can look to the expiration date on a bottle of sunscreen to determine how long it will last. The only exception to this is when a manufacturer has proven its product to last at least 3 years.
“For optimal sun protection as well as texture, stability, and sterility, use the sunscreen prior to the expiration date,” says King.
Once sunscreen has expired, it becomes less effective at blocking UV rays, therefore increasing your risk of sunburn and skin cancer. In addition to this, exposure from direct sunlight and high temperatures can cause sunscreen to become less effective over time.
“The heat and sun can break down the chemicals and render them ineffective and potentially irritating to the skin,” explains King.
To determine whether sunscreen has gone bad or not, look to the expiration date stamped on the packaging.
“If there isn’t a specific expiration date, then you can assume it’s good for 3 years past its purchase date, according to the FDA,” says. King.
Be sure to discard any unused sunscreen after this date as it may no longer be effective in preventing sunburn.
Since some countries don’t require the use of expiration dates on sunscreen, it’s a good idea to write down the month and year you purchased it (for example, with a marker on the bottle).
Another indicator is any obvious changes, such as how it smells or how it applies to your skin. If the smell or consistency is off, toss it.
Lastly, use your own judgment. For example, if you’ve left a bottle of sunscreen in a hot car for a year, it’s probably gone bad.
Keep sunscreen in good condition by storing it in a cool, dark place. Exposing the container to excessive heat or direct sun can cause its ingredients to become less effective.
When outdoors, you can protect sunscreen by wrapping the bottle in a towel or placing it in the shade. Keep the lid on firmly at all times.
If you’re going to be out in the sun for a long time, you can store sunscreen in a cooler. Another idea is to apply sunscreen indoors so you can avoid taking it out in the sun.
Turns out, expired sunscreen is better than no sunscreen.
“If it’s only slightly past the expiration date and the sunscreen looks, feels, and smells normal, then I would feel OK about using it if I didn’t have another option,” says King.
This is especially true if the active ingredient is a physical sunblock like zinc oxide or titanium dioxide. King explains that this is because they’re photostable.
This means that they “do not change their molecular structure when exposed to UV radiation. Physical sunblocks once had an opaque, paste-like consistency but over the past several years manufacturers have developed more cosmetically elegant formulations by micronizing the particles.”
She adds that micronized zinc oxide and titanium dioxide can clump together over time so the particles are coated with dimethicone or silica to keep the ingredients stable and smooth.
Other means of sun protection
If you’re caught out in the sun with expired sunscreen, there are other means of sun protection.
There’s sun-protective clothing, for instance. This includes anything from hats to long-sleeve T-shirts to a bathing suit cover-up. You can purchase clothing made with UPF (ultraviolet protection factor) built right into the fabric. This refers to how much UV is blocked.
However, UPF-treated fabric won’t protect you entirely without sunscreen, so it’s important whenever possible to have both.
According to FDA regulations, sunscreen has a shelf life of 3 years. For the best sun protection, use your sunscreen before the stated expiration date and store it in a cool, dark place.
Expired sunscreen may be better than no sunscreen, but it’s always important to have some sort of sun protection when outdoors, rain or shine.
Most important, discard sunscreen that has any obvious changes in color, smell, or consistency. Remember: When in doubt, throw it out!
Above all, sunscreen is meant to be used. A liberal application is around one ounce, so a bottle shouldn’t last you too long.