Do You Know about Sunscreen?
- Posted on: Apr 15 2022
As we look forward to sunnier days in the coming weeks and months, we also have to start thinking of the ways in which sun exposure can affect our skin. Regardless of age, every person can benefit from sunscreen use. As we meet with patients for skin cancer screenings and cosmetic treatments that correct the signs of sun damage, we are reminded that sunscreen use is not well understood by everyone. Here, we answer some common questions that may help you navigate your summer with the healthiest skin possible.
What SPF Number is the Best?
SPF stands for Sun Protection Factor. All sunscreen is protective. The question is, how much? There are a few common SPF factors, designated by a number. The SPF factor in a sunscreen indicates the amount of UVB light the product will block. People often think that they will benefit more from a high-SPF sunscreen. This isn’t necessarily the case. Most dermatologists recommend that patients wear SPF 30. While a higher SPF certainly won’t hurt the skin, it provides only a slightly higher amount of protection, as is indicated by the percentages here:
- SPF 15 blocks 93% of UVB rays
- SPF 30 blocks 97% of UVB rays
- SPF 50 blocks 98% of UVB rays
Understanding SPF can be difficult. Some sources say that SPF multiplies the length of time it would take for the skin to burn. That magnification is 10. So, if your skin would burn within 10 minutes of being in the sunshine, SPF 15 would elongate that time to 150 minutes. SPF 30 to 300, and so on. Gauging sunscreen in this way can be risky. Every person’s skin is unique and will react differently to the sun. For this reason, the general recommendation is that, regardless of the SPF number you wear, you should reapply sunscreen every two hours. Sunscreen also needs to be reapplied if you sweat or swim.
Why is Broad-Spectrum Sunscreen Recommended?
There are two types of ultraviolet light in sunshine, UVA and UVB. Sunscreen generally protects against UVB light, indicated by its SPF. UVB contributes to premature aging, skin discoloration, sunburn, and skin cancer. However, UVA light does, as well, contribute to all forms of skin cancer, including melanoma. UVA light is always present, even on cloudy days. It is not filtered by the Earth’s ozone layer. It penetrates through windows and windshields so, while it may not always cause sunburn, it can always affect skin that is not protected by sunscreen or SPF clothing. The best way to protect the skin from UVA and UVB light is to wear a broad-spectrum sunscreen.
How Much Sunscreen Should I Apply?
SPF matters only so much. If you’re not applying enough sunscreen to coat your skin, the effects of your SPF will be lessened. So how much sunscreen do you need? For your face, you need half a teaspoon. For the remaining areas of your exposed skin, you need an ounce. For a visual, a shot glass is about an ounce. According to surveys, most people do not apply enough sunscreen. Also, most people do not apply sunscreen around the eyes, which can significantly increase the risk of premature aging and skin cancer on the eyelids. Sunscreen should be applied even if moisturizer or makeup contains SPF. The exception may be if an SPF mineral powder is applied over makeup.
In addition to wearing sunscreen, it is vitally important to see your dermatologist yearly for a thorough skin cancer screening. To schedule yours, contact our Teaneck, NJ office at 201.836.9696.