Have you ever had that nagging feeling that you’re forgetting something? Ever since I wrote the column on sunscreen that appeared in the June 21 edition of this newspaper I’ve thought that I left out something really important.
Then I remembered a woman I used to work with coming in one Monday with the worst sunburn you could imagine. She was redder than any strawberry you’ve ever seen, and terrifically uncomfortable.
“The strangest thing is that I used tons of sunscreen,” the woman said in defense of her blisters. “Who knew that sunscreen EXPIRES?”
That’s what I forgot to tell you!
The Mayo Clinic says that if you use sunscreen properly, a container shouldn’t last long. “A liberal application is one ounce, the amount in a shot glass, to cover exposed parts of the body. You might need to apply more, depending on your body size. If you have a four-ounce bottle, you’ll use about one-fourth of it during one application.”
But, we all have half used bottles and tubes lying around. How do we know that the sunscreen is still effective? Read the label. Most sunscreens will have an expiration date printed on it.
Also think about where it’s been kept. Sunscreen stored in the sun and heat will lose its stability and efficacy. So, keep the sunscreen away from direct sunlight in as cool and dark a spot as possible.
At the Skin Cancer Foundation’s website, Karen E. Burke, MD explains that in order to test shelf life of a product, manufacturers store sunscreen at 40 degrees Celsius with 25 percent humidity. They then test it at 0, 1, 2 and 3 months.
“Stability for three months in these laboratory conditions is comparable to three years in normal ambient environments. So your sunscreen should be good for up to three years after purchase,” Burke said.
The website Verywell.com says, “If there is no expiration date, you can always call the customer service number that’s listed on the label. You can provide them with the codes that are printed on the bottle and they can tell you whether or not it has expired. The codes printed on the label track the date, batch, and location of where your bottle was manufactured.”
Dr. Burke suggests you write the date you purchased the sunscreen with a marker right on the container if the manufacturer doesn’t provide one. If you can’t remember when you bought it, be safe and throw it away.
What happens is that the chemicals in the sunscreen begin to degrade and separate after a period of time making them less effective.
“Eventually, old sunscreens will crystallize and separate, and they may have a foul odor.” Verywell says. “When in doubt, toss the old sunscreen that you have and buy a new one.”
I know, that was said already, but it’s good to repeat it. They also remind you to make sure the new one states “broad spectrum” on the label and has at least an SPF (sun protection factor) of 30 or higher.
Every article I read states that the optimum protection is when you apply sunscreen liberally and reapply regularly. If you use an old product, you may still get protection, but it’ll take a larger quantity and you’ll need to use it more often.
Verywell says it’s important to use sunscreen year round. “When you’re exposing less skin to the sun’s UV rays, you don’t have to use as much. However, you still need to protect the skin that is exposed, such as the hands, the face, the ears, the neck, and if you’re balding, the top of the head.
“And don’t forget about exposure to the sun through car windows (especially on your left forearm and left hand) and perhaps through your office window.”
Enjoy these wonderful long, sunny days without the pain and discomfort of a sunburn. Your skin will thank you for it.
Kathy Hubbard is a member of Bonner General Health Foundation Advisory Council. She can be reached at 264-4029 or firstname.lastname@example.org.