A few people have asked me why doTERRA's sunscreen is SPF 30 and not SPF 50. So, I thought I would share some more detailed information about sunscreen with you this week.
First of all, let's talk about what SPF is (and what it isn't). Sun Protection Factor represents how much more time you’ve got in the sun before your skin might react, compared to when/if you weren't wearing the protection. The "factor" number is the multiple you use to determine length of time; it does not represent the percentage of harmful rays blocked.
SPF 30 sunscreens block 97% of harmful UVB rays
SPF 50 sunscreens block 98% of harmful UVB rays
SPF 100 sunscreens block 99% of harmful UVB rays
You can see that the higher SPF ratings actually don't much increase the percentage of harmful rays blocked.
It's also important to note that the SPF of a sunscreen can’t determine the actual amount of exposure time that's appropriate for your skin. That depends on your skin type, the amount of sunscreen you’ve applied, the intensity of the sunlight, and your sunscreen’s SPF rating. Reactions include mild reddening to actual sunburn, not to mention the invisible damage typical of UVA rays.
Let's talk about UVA rays, too. A sunscreen’s SPF rating has little to do with its capacity to shield the skin from UVA rays. While UVB rays cause sunburn, UVA rays cause other damage such as suppression of the immune system, formation of harmful free radicals in skin, and development of melanoma. It's important to note that as SPF increases, the ratio of UVA protection in it decreases.
Sunscreen products with high SPF values may, in fact, overexpose consumers to UVA rays and raise their risk of cancer, according to the FDA. Many studies have found that people are more likely to use high SPF products improperly and, as a result, may expose themselves to more harmful ultraviolet radiation than do people who rely on products with lower SPF values.
There are four strikes against high SPF values:
Poor balance. As a result of inadequate UVA exposure standards and limited options for providing UVA protection, sunscreens offer far less protection against UVA than UVB rays, and this is worse for products with the highest SPF values. High SPF products suppress sunburn much more effectively than they protect from UVA-induced damage.
Consumers misuse high SPF products. High SPF products tend to lull users into a false sense of security, so they stay in the sun longer and overexpose themselves to both UVA and UVB rays well past the point when users of low SPF products would head indoors. As a result, they get just as many UVB-inflicted sunburns as unprotected sunbathers, and are likely to absorb more damaging UVA radiation.
Sunburn protection is only marginally better. Sunbathers often assume they get twice as much protection from SPF 100 sunscreen as from SPF 50. But the extra protection is negligible. Properly applied SPF 30 blocks 97 percent of UVB rays, while SPF 50 blocks 98 percent of UVB rays. SPF 100 blocks 99 percent. When used correctly, sunscreen with SPF values between 30 and 50 offers adequate sunburn protection, even for people most sensitive to sunburn.
For chemical sunscreens, high SPF products may pose greater health risks. High SPF products require higher concentrations of sun-filtering chemicals than low SPF sunscreens do. Some of these ingredients have been linked to tissue damage and potential hormone disruption. Some may trigger allergic skin reactions. If studies showed that high SPF products were better at reducing skin damage and skin cancer risk, the extra chemical exposure might be justified, but they don’t.