Many believe if the SPF is ‘higher’ then your sun protection will equivalently rise too. This isn’t the case. While an SPF 15 will block around 93 percent of UVB rays, doubling the SPF to 30 will block 97 percent. That’s just a 4 percent increase – for what would appear to be double the dose.
For ‘higher’ SPFs, those of SPF 50 and more, there is only a one percent increase, never enough to reach 100 percent. Dermatologists say there is no real difference between using an SPF 15 or 30 and using SPF 50 or greater.
SPF levels are also a gauge of how long it takes to become sunburned compared to how long it takes to burn without wearing sunscreen. If you generally take 20 minutes to burn, an SPF 15 should allow you to go 300 minutes before burning. However, it is neither recommended nor safe to go 300 minutes in the sun before putting on more sunscreen. Ever.
Generally an SPF 15 is sufficient, especially if it can be worn when swimming. For maximum protection against prolonged exposure to the sun, it is highly recommended to also wear protective clothing, a hat and effective sunglasses.
Why use an SPF 15 daily, rather than SPF 30 or 50?
- SPF 15 is the ideal SPF for most sun exposure situations without the double chemical load (sun screening chemicals) of SPF 30 and above.
- SPF 15 gives similar sun protection as ‘higher’ SPFs when applied every two hours (as all sunscreens must be).
