What to pay attention to when using sunscreen
You should protect yourself from the sun's rays in summer by applying sunscreen. This raises the question of whether last year's sunscreen can still be used? Dermatologist Dr. According to Alok Vij of the Cleveland Clinic in the United States, caution is in order here.
Sunscreen spoils faster if stored improperly
according to doctor Vij sunscreen is very capable of breaking down. When stored incorrectly, it happens even faster than most people realize.
Sunscreen usually has a shelf life of about three years
“The general shelf life of sunscreen is around three years as long as it is stored in a cool, dry place,” the expert said in a press release.
However, if sunscreen is left in a warm or humid place, many active ingredients that block UV rays can break down quickly, explains the dermatologist.
The expert adds that if used correctly, the sunscreen will wear off pretty quickly anyway. "In reality, if used as directed, one bottle should not last more than a few months," Dr. Vij points out.
If you follow the recommendation, it's entirely possible to use up an entire bottle in a single day or a few weeks if you spend a lot of time in the sun.
If you still have sunscreen at the end of summer, the expert advises storing it in a cool, dry place during the winter.
Note the expiration date or purchase date
according to Dr. Vij has an expiration date printed on the label or bottle of some sunscreens, but not others. It is therefore advisable to write the date of purchase of the sunscreen on the bottle. In addition, correct storage must be observed so that the effect is maintained.
Does mineral sunscreen last longer?
Whether mineral or chemical sunscreens are used, all the ingredients contained are not stable over time.
So-called dispersing agents are added to both forms of sunscreen to distribute them more evenly on the skin. However, these can degrade over time, which can change the texture or cause an uneven protective effect, explains the expert.
If preservatives in sunscreen break down, bacteria can take hold, which can lead to breakouts and acne, the expert continues.
Titanium and zinc are not normally degraded in mineral-based sunscreens. For this, however, other stabilizers are disassembled. If the means are low, according to Dr. Vij small lumps appear. Often these expired sunscreens can no longer be spread or rubbed into the skin well.
Chemical-based sunscreens spoil faster
In general, according to the expert, chemical-based sunscreens tend to spoil faster. This is especially true when the product is in the sun.
Two active ingredients found in chemical-based sunscreens are among the most unstable ingredients. According to the doctor, these are avobenzone and octinoxate.
Allergic reaction from oxidized ingredients
When the active ingredients oxidize, allergic contact dermatitis may occur. It looks like a burning sunburn, but it's actually an allergic reaction caused by the interaction of light and heat with the chemicals in the product.
Keep the sunscreen clean
In order to avoid problems with sunscreen, the product should always be kept clean and the lid should be tightly closed after each use. Also, the lid should not be opened and closed unnecessarily often, according to the expert.
The sunscreen container should also not be exposed to direct sunlight. This applies to storage as well as when bathing on the beach, for example. In such a case, the product should be protected from the sun with a towel or blanket, advises Dr. Vij.
Better to use a new sunscreen
In summary, it can be said that it is important to apply sunscreen in the summer, but care must be taken that these are always fully effective and do not become contaminated. If in doubt, it is better to buy a new sunscreen instead of using the old one from the previous year.(as)
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This text corresponds to the specifications of the specialized medical literature, medical guidelines and current studies and has been verified by health professionals.
Sources:Cleveland Clinic: Does sunscreen expire? (published 2022-06-30), Cleveland Clinic
This article contains general advice only and should not be used for self-diagnosis or treatment. It cannot substitute a visit to the doctor.