There is a lot of misinterpretation regarding Sun Protection Factors, such as how they work and what to look for when selecting a product, so let’s look at the facts.

What does the SPF number represent?

The SPF number indicates the percentage of UVB rays (burning rays) that are blocked. Unless the packaging states UVB & UVA (rays that cause aging) Broad Spectrum protection, the SPF refers only to the percentage of UVB rays that are blocked.

Many believe that the higher the SPF number, the longer they can remain in the sun without a reapplication. Although the higher number does provide more protection, it does not provide an increased timeline for safe sun exposure. All SPF products need to be reapplied, approximately every 2 hours, to be effective.

The SPF number indicates the percentage of the sun’s rays that are filtered. You would think that the protection would increase exponentially, however, this is not the case. The protection almost plateaus with a very minimal increase after an SPF of 15, however, most prefer using an SPF of at least a 30 or higher.

Physical (or mineral) VS. chemical sunscreens

Physical: Titanium Dioxide and Zinc Oxide are physical filters that provide both UVA & UVB protection. These are considered physical filters, as they deflect the sun’s rays and don’t allow them to penetrate the epidermis.

Chemical: Oxybenzone, Homosalate, Octisalate, and Avobenzone are chemical filters that absorb the sun’s rays, preventing them from penetrating and damaging the skin. Chemical filters are often unsuitable for sensitive skin. Heat is produced by a chemical reaction on the skin, as the chemical filters absorb the rays, which may cause discomfort and rashes for some. Although chemical filters are suspected of being a health risk, as they do penetrate the skin, to date, there is no evidence confirming that this is true.

Unlike with physical filters, when sun protection products contain chemical filters, they must contain a combination of filters, as no single chemical filter can filter both UVA and UVB rays.

To conclude, a sun protection product should be applied daily. When spending time outdoors, it is recommended to reapply your SPF every 2 hours to ensure maximum protection.

It is also recommended to also wear protective clothing and to avoid the sun between 10 am and 3 pm when it is the strongest.