When it comes to SPF, proper storage and disposal matters.

We're all into bulk buying, but the one thing you should never buy in bulk? Skincare. And within the realm of skincare, SPF is probably the most imperative of them all. 

That's because when it comes to the proper storage and disposal of sunscreens, you really don't want to mess around—an expired or spoiled sunscreen can cause major damage to your skin, and considering skin cancer is the most diagnosed form of cancer in the country, it's important to use sunscreen responsibly.  

We tapped two experts to get their advice on how to properly store sunscreens for the season, and then dispose of any expired products that haven't been used. Spoiler: The sunscreen that's been in your bathroom drawer for five years probably won't do much to protect you this year.  

Shelf Life of Sunscreen

The FDA requires that sunscreens maintain their full strength for three years, even if they've already been opened.  "If the sunscreen you are using has an expiration date on the package, be sure to use it prior to this date," says Brooke Jeffy, MD, a board-certified dermatologist at Pore House. "If your sunscreen does not have an expiration date, you can assume effectiveness for three years past the purchase date, as long as it is stored at room temperature." 

If your sunscreen bottle doesn't have an expiration date on the bottle, Krupa Koestline, a clean cosmetic chemist and founder of KKT Consultants, recommends using a Sharpie to note when you purchased it and toss it if it's past three years. "Generally, you should be applying SPF so liberally that a bottle should be used up well before that three-year mark," she says.

If you suspect your sunscreen might be past its due date, Koestline suggests looking out for the telltale signs of degradation in the formula. "Any time when the texture or color changes, showing degradation of the formula, you would want to dispose of it," says Koestline. "If it comes out watery and it's not supposed to, or if it's a darker brown color, indicating oxidation, toss that SPF and get a new bottle." It's not so much that the active ingredients are not effective, as UV filters past the expiration date (mineral filters, given that they are minerals, do not degrade under UV exposure), but the formula may no longer create a uniform film over your skin to effectively protect it from UV rays.

how-to-dispose-of-expired-sunscreen: bottles of sunscreen
Credit: Getty Images

Best Way to Store Sunscreen

As with almost all beauty products, you want to store your sunscreen out of direct light and in a cool place. "Avoid exposing it to extreme heat or sun, like inside your car," suggests Koestline. "If you're taking SPF with you to the beach or pool, store it in your bag and in the shade." You also want to keep your sunscreen away from humid places like the bathroom, which is more prone to causing mold buildup.

Excessive heat and sunlight on a bottle of sunscreen will lead to a loss of effectiveness. "I always recommend applying sunscreen indoors before going out, but if you need to keep it with you outdoors, wrap it in a towel and keep it in the shade or in a cooler," says Dr. Jeffy.

Best Way to Dispose of Sunscreen

Disposing and recycling sunscreens really depends on where you live—every city has slightly different recycling rules, and every brand uses different packaging materials. "Some components of the packaging can be readily recycled, while there might be a cap that's not recyclable," explains Koestline. "Most of the time, aluminum cans can be readily recycled, but it's still best to check with your city."

Now for the tricky part: the contents. Although we wish it was as simple as running the products down the drain, these ingredients will eventually end up at the wastewater treatment plant and out into local waterways, where they can harm aquatic life. 

In the most ideal scenario, you should try to use up all of your sunscreen before the expiration date, but if it's past its expiration date and isn't fully empty, "tossing the container and leftover sunscreen into the trash may be acceptable if your landfill is lined, which helps prevent unused sunscreen components from entering the water supply," says Dr. Jeffy. 

If you're not certain whether your sunscreen is reef-safe, rather than dumping it down the drain, Koestline recommends scooping it into the trash can first. "There are no ideal solutions, really, except to be conscious of your SPF purchase and make sure you use it all up to reduce overall waste," she says. 

Another option is to maximize your sun protection in other ways in order to minimize the need for sunscreen. "Minimize your environmental impact by wearing sun-protective clothing and wide-brim hats, staying in the shade, and avoiding midday outdoor activities if possible," explains Dr. Jeffy.