Ingredients Explained: SPF – What should you be looking for?

July 18, 2014


I have wanted to write this post for awhile – and as it is summer this is the best time to start! So let’s dive into sun protection, SPF and what we should be using.

So what is UV and why should we be worried about it?

As we all know the sun produces Ultraviolet (UV) waves – these are like the rays of light except we can’t see them and they have the ability to be absorbed by our skin. Most of these rays are filtered by the ozone layer so we only get a very small fraction (we couldn’t survive without this!), however, some of the rays which do reach us are absorbed by our cells and disrupt our DNA.

Our skin is protected by a substance called melanin, this is a protein pigment produced by cells which stops the waves from being absorbed. When we are exposed to the sun, we produce more melanin, which in turn gives us a tan. However, too much exposure results in DNA damage, the DNA gets disrupted by the waves making it unstable. This can result in freckles, moles, premature ageing, growths and even cancer. Should you be worried about disrupted DNA due to increased sun exposure it would be a wise idea to see your local healthcare professional or find one by looking at various location services through this website and others.

There are several types of UV rays, however the two we are concerned with are UVA and UVB. UVA does not damage the DNA directly, but through producing other substances which harm it and the collagen in the cell which results in premature ageing, whereas UVB causes direct DNA damage which results in the skin burning. Luckily, we can do something to protect ourselves from both of these!

What is SPF?

SPF stands for sun protection factor and is found in products which protect our skin. We can put substances on our skin which block the UV rays and protect our cells from DNA damage. The amount of sun protection in a product is determined by the SPF number on the packaging. This number can range from 5 all the way up to 85!


How does SPF work?

The sun protection doesn’t come from the SPF itself, this is just a way of seeing how well the ingredients in it work. There are two types of ingredients which protect us from the sun:

  • Chemical compounds which absorb the light, this acts like the pigment in our skin to absorb the rays before they enter the body and our cells.
  • Particles which reflect and scatter the light, this acts as a barrier, causing the rays to bounce back and not enter our skin.

SPF is not measured in a linear scale, so SPF 80 is not four times better than SPF 20. In reality SPF 30 blocks out 98% of the suns rays whereas SPF 50 blocks out 99%. So in reality, it isn’t worth spending extra on a higher number.


What Should I be Looking For?

  • You need to make sure you are using a broad spectrum sun protection product. This should ideally state on the packaging that it protects from both UVA and UVB rays to get full protection. These are also often labelled sun block rather than sun screen.
  • Do not go under SPF 20 – ideally you are looking for SPF 30. As above, there is not much point in going higher than this, especially if it’s more expensive.
  • Recent research suggests that SPF should be applied then reapplied around 15 minutes later to get the full benefit of the UVA protection. I recommend applying moisturiser with sun protection in as soon as you wake up, then I reapply again when I am doing my make up.
  • You should be aiming for around 1/3 to a 1/2 of a teaspoon to cover your face.
  • PA+ is a different scale used for SPF – it means the same as the SPF number so just keep an eye on that.
  • Sun protection is very rarely effective in water, always apply as soon as you get out of water and do not believe when a product states that it is water resistant!
  • Cosmetic tans, such as through using sunbeds or after a day out in the sun are caused because of exposure to UVA, resulting in already produced melanin to be released, whereas a prolonged tan which develops over weeks is as a result of exposure to UVB. The tan from UVA does not protect our skin in any way as it is the same amount of melanin as when you were not tanned, keep this in mind over summer when you think you may need less SPF!
  • Always remember to protect your skin in other ways – loose fitting clothing which covers the arms and legs, a sun hat, and sunglasses are a great place to start!
  • Try and avoid the sun at the hottest parts of the day – between 10 and 3 in summer.

I hope that was useful to you all – I will hopefully be doing another post on my favourite sun protection products so keep an eye out for that one soon!

I have done some other ingredients explained on collagen, keratin and parabens so please check them out! If you have any suggestions for other topics in this season then let me know.

JC xx

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