Sunscreen uncovered. Do I really need Factor 50?

I always wear a factor 50 suncream on my face, every day, on top of my moisturiser and under my primer, even if my primer also has an SPF.  Apart from the fact that most of the visible signs of ageing are due to sun damage, I also use retinol as part of my skin care routine which can lead to even more damage if you don’t protect your skin.  So I am very aware of sun protection.  I just automatically assume that factor 50 must be better but is it overkill? I’ve been doing some research on sunscreen and here are a few bits of information you will hopefully find useful.

The sunlight that reaches us is made up of two types of harmful rays: long wave ultraviolet A (UVA) rays which penetrate deep into the dermis, the skin’s thickest layer, and short wave ultraviolet B (UVB) rays which will burn the superficial layers of your skin.  It used to be thought that just UVB rays were responsible for skin cancers but more research is showing that UVA rays contribute as well.  SPF (sun protection factor) is a measurement of sunscreen protection from UVB rays, it does not measure how well a sunscreen will protect from UVA rays.  

I was surprised to find that the SPF scale is not linear, factor 30 isn’t twice as effective as factor 15:

  • SPF 15 blocks 93% of UVB rays
  • SPF 30 blocks 97% of UVB rays
  • SPF 50 blocks 98% of UVB rays


So in effect SPF 30 only gives you 4% more protection than factor 15.  However, I will take take that extra few % and stick with my factor 50.

We should make sure that we use what is known as a “broad spectrum sunscreen”.  These offer protection against UVA and UVB, the UVA protection should be at least one third of the UVB protection.  On the packaging look for the letters UVA in a circle, this indicates that the product meets EU standards. There is also a ratings system of 1 to 5 stars which measures the amount of UVA protection. Obviously the higher the star rating, the better.



So, how much protection does a sunscreen actually give you. A very rough estimate is, if your skin would burn after around 10 minutes in the sun, then applying a factor 15 sunscreen would allow you to stay in the sun without burning for around 10 times longer (150 minutes).  However, this obviously depends on other factors, including whether you have applied the correct amount of sunscreen. Most people only actually use around half of what is recommended. The NHS website states :

“As a guide, adults should aim to apply around two teaspoons of sunscreen if you’re just covering your head, arms and neck; two tablespoons if you’re covering your entire body while wearing a swimming costume.”  

Apply 30 minutes before you go out and then also just before you go; reapply every 2 hours. Use a water resistant product if you’re going in the pool, I always re-apply as soon as I get out and am dried off.  The cooling effect of water can make you think you’re not getting burned. Bear in mind that water reflects ultraviolet (UV) rays, increasing your exposure.

Also, don’t fall into the trap of thinking you just get sunburnt on holiday.  Up to 20% of the sun’s harmful rays can penetrate your skin even on a cloudy day in the UK. Try to stay in the shade when the sun is at its strongest, usually somewhere between 11 and 3 and obviously, carefully monitor children in the sun.  I’m never without a wide brimmed hat in the sun, even though it doesn’t do my hair any favours!

Keep an eye on the expiry date of your sunscreen, it doesn’t last forever.  Expired sunscreen has literally fallen apart, you will get zero sun protection.  Personally, I throw any remaining sunscreen away around March each year and get new products ready for the summer.

What if you look at your time in the sun as essential for topping up Vitamin D, so you think that not wearing a sunscreen will help with this? As long as you are eating a healthy diet, most people can fulfill their Vitamin D requirements with normal daily outdoor activities amounting to 5 to 30 minutes twice a week.  Prolonged sun exposure gives no extra production of necessary vitamin D, it will only expose the skin to the harmful effects of ultraviolet radiation, e.g. skin cancers and photodamage. 


Don’t forget your after sun products.  After sun lotion is essential for rehydrating sun burnt skin. It also helps to repair your skin by cooling it down and locking in lost moisture.   It absorbs much faster if applied to damp skin. I always take some aloe vera gel with me on holiday just in case my after sun product needs an extra boost.  


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