Amarya Blog

So we’ve all just had our Easter Break and have been enjoying this unusually glorious sunshine. We’re all back now for the daily grind but having had a taste of the sun so early on in the year our thoughts are now turning to the longer summer holidays in a couple of months time.

All this talk of sunshine got us thinking here at Amarya about sun creams and sunscreens and especially the term ‘SPF’.

We were slightly concerned about the number of people who didn’t understand the ‘SPF’ labelling and how it affected them in the sun so we thought we’d take a couple of minutes out and put together a little article explaining how it all works.

Well, as all the best books say, let’s begin at the beginning.

The letters SPF actually stand for Sun Protection Factor.

The most commonly advertised Sun Protection Factors are usually SPF15, SPF20 & SPF30 but they can actually range from 2 to 70.

But what do the numbers mean for you?

Well the SPF ratings have been with us since the early 1960’s and back then scientists took a group of volunteers and subjected their skin to direct sunlight and noted how long it took each volunteer to ‘burn’ in the sun. They then applied the sunscreen and redid the test, taking note this time of the lengthened time before the volunteer burned. They then divided the ‘after’ by the ‘before’ and rounded the figure off to the nearest 5 for simplicity.

In theory then to find out how long can you stay safely in the sun you first write down the number in minutes you would normally expect to burn without any sunscreen and multiply it by the SPF on the bottle of sunscreen you’ve bought. The result is the time in minutes, you can stay safely out in the sun.

But recent studies however have raised concerns over this formula due to the amount of sunscreen used by the scientists in their laboratories and us regular folk down on the beach or in the back garden. In fact the studies showed that the scientists were using roughly TWICE as much as we usually do.

So now, to find out how long you can stay safely in the sun for use this formula instead:

Minutes you can stay out in the sun without sunscreen before burning MULTIPLIED by the SPF, DIVIDED by half.

For example, if it takes you 15 minutes to burn usually without sunscreen and you used a sunscreen with an SPF of 20 you will do:

15 x 20 = 300 minutes then divide by half gives you 150 minutes (or just over 2 hours) of protection from the sun.

Now remember this is not ‘carved in stone’ as other variables can come into play such as the weather, clothing or whether you’re being active or passive in sun. There’s a big difference between doing 2 hours of gardening at home where you’re constantly going backwards and forwards in and out of the house or shade to 2 hours lying motionless sunbathing in direct sunlight.

Of course, we at Amarya would like to go that one step further and suggest using a sunscreen that is made from natural or organic ingredients that still have an SPF rating but don’t contain the other chemical nasties that maybe found in others.