Your guide to Sun Screens


Have you ever tried to read the back of a bottle of sunscreen and given up in despair? Not know your SPF from your UVB?

You are not alone. In fact, the Royal Pharmaceutical Society has stated that a quarter of UK residents do not know what the rating on the front of the bottles means.

It’s not surprising. With so many acronyms, who has the time to swot up and learn them all? Luckily we have done the homework for you.

So here is your basic guide to understanding sun screen jargon:

What does SPF mean?

SPF means ‘sun protection factor’ and will represent how many more times you can now sit out in the sun with the sun screen on. This is compared to having no sun screen protection at all, before you will burn.

To give you an example, if you can normally sit out in the sun for 10 minutes before your skin burns, and you apply a sun screen with an SPF of 15, you should be now able to sit outside for 150 minutes.

If you can sit outside in the sun for 20 minutes in the sun and you chose an SPF10, you could now prolong your sun exposure up to 200 minutes.

You must keep reapplying your sun cream however. So if you take a dip in the pool put some more cream on. And be sure to come out of the sun when your time is up.

As for the higher SPF factors, there is criticism of the efficacy once you get over factor 30. Some experts believe there is not that much difference between SPF 30 and SPF 50. For instance, factor 15 will absorb 93 per cent of UVB rays, whilst factor 30 will absorb 97 per cent and factor 50 absorbs 98.

And remember that SPF factor will typically only protect you from UVB rays, and not UVA.

What are UVB rays?

UVB rays are the radiation emitted by the sun. These are medium rays that only penetrate the top layers of your skin.

UVB rays are the main cause that your skin will redden and burn in the sun. These types of rays are more prevalent during 10am and 4pm and are linked to sunburn and skin cancer.

What are UVA rays? These are the longer types of rays and as such, penetrate deeper into the skin’s epidermis.

UVA rays are responsible for immediate tanning, but can cause ageing of the skin, DNA damage and have strong links to skin cancer.

How to protect against UV rays?

When buying sun screen you should always purchase those that offer protection against both UVA and UVB rays.

Always look for a sunscreen with an SPF of 15 or higher, and choose one that has the phrases ‘multi spectrum’, ‘broad spectrum’ or ‘UVA/UVB protection’ on sunscreen labels.

If you are not sure, then pick a bottle that has a ‘UVA logo’ on the bottle. This means the UVA protection will be one-third of the protection against the UVB amount.

How much should you apply?

It is an accepted rule of thumb that you should apply around a teaspoon for the face, for each arm, each leg, the front of the body and the back. So in all, allow about 35ml of sun cream for the whole body.

Make sure you apply the sun screen around 20 minutes before you head off into the sun, this is to allow your body to absorb it.

What’s the difference between water resistant and waterproof?

No sun screen is ever fully waterproof, so really the term should not be used.

Reapply your sun screen every time you go swimming, or even after you have been exercising or perspiring.

Remember, when out in the summer sun, try to avoid the hottest times, during 10am and 4pm, stay in the shade, apply the maximum SPF factor to children and regularly top up the sun screen and always drink plenty of water to avoid sunstroke.

Show Comments

No Responses Yet

    Leave a Reply

    This site uses Akismet to reduce spam. Learn how your comment data is processed.