We are having some sunny, sunny, sunny days. Days meant for the liberal use of SPF 50. Or higher even?

Controversy of controversies, people are arguing about sun screen! Fifty years ago if we wanted sunscreen we wore hats and long sleeve shirts outdoors. Did you think those baseball uniforms were just a fashion statement? If you slathered anything on your skin it was most likely a splash of Coppertone or Sea & Ski hoping for a deep, dark tan rather than hoping to not get skin cancer.

Today, everybody knows of the dangers of overexposure to the sun and the significant health consequences that go beyond cosmetic considerations. But still people question. For some reason, all countries don’t use the same rating system for sunscreens but most people recognize the SPF ratings even if they all don’t know what those numbers mean. Like nutrition and politics, many people are content to get their skin protection news and information from late night TV and underemployed comedians.

It’s been established that SPF 15 blocks 93% of UF-A rays, those rays that are responsible for skin damage including melanoma. Does SPF 30 protect the skin from twice as many sun rays? Yes and no. The companies that don’t make products with higher SPF ratings will tell you that you can’t block more than 100% of anything. And darned if they aren’t true. And they continued to be true until they came up with their own SPF 30 which blocks 97% of those rays or an SPF 50 product blocking 98%. Let’s review. A jump in 15 SPFs increases the protection by 4% then the next 20 of those SPFs got us just another 1%. So where does that leave the new SPF 100 with its mammoth leap of 50 SPF thingies?

Instead, let’s look at what those SPF numbers are. Although you can quantify how much blockage they impart, that number on your sunscreen bottle isn’t a reflection of sun blocking. It’s actually the Sun Protection Factor or an estimation of how long you can stay exposed to the sun. An SPF 15 sunscreen means you can be in the sun for 15 minutes before you experience the damage unprotected skin experiences in one minute. SPF 30 gives you 30 minutes of exposure before seeing that damage, and so on.

You don’t double the amount of sun blocked by doubling the SPF but you double the time you can be in the sun without incurring the amount of damage your skin will experience. Or before having to reapply to extend that time.

Oh, another thing about sunscreens. Those SPF numbers were calculated based on exposure to UV-A rays, the ones that cause potential skin cancers and other damage. Old fashioned sun burn is caused by UV-B rays. Not to worry though. Find a sunscreen that says it is “broad spectrum” and protects against both.

Umm, until you get wet. Then, you probably want to reapply regardless if how long it’s been since you last slathered.

We now return you to your regular program. Or to the sun porch.