From the cancer research site....
Cheap sunblocks are usually just as good as expensive ones. They are all tested the same way and it is the the level of protection they give you against the sun that matters most. This is the 'sun protection factor' or SPF.
Do check the 'use by' date. Most creams will last about 2 or 3 years - so it is OK to use last year's, but not a bottle from 5 years ago!
Sun creams have changed a lot in the past 15 years. There is a huge range and it can be difficult to know what to buy. You should choose one that says it protects against both UVA and UVB radiation from the sun. This may be labelled 'broad spectrum'.
The SPF tells you the amount of protection the sun cream gives against UVB radiation. We recommend at least factor 15. This is because it gives the best balance between protection and cost. The higher factor creams are more expensive, but do not give much more protection than factor 15. If you use
- Factor 15, only 7% of the harmful UVB rays will get through
- Factor 30, only 4% of the harmful UVB rays will get through
- Factor 60, only 2% of the harmful UVB rays will get through
So you can see, you are getting some more protection with the most expensive creams, but not that much more. There is no sun cream that can give you total protection. 98% protection (with factor 60) is about the best you will get.
UVA protection is shown by 0 to 5 stars. But, this is only a rough guide because it is also affected by the SPF. A cream with SPF 25 and 3 stars may give more UVA protection overall than a cream with SPF 10 and 4 stars.
Don't assume that because you have put on sun cream, you can stay out without burning. Keep an eye on your skin (and your children's skin) at all times. Children have thinner, more delicate skins than adults and are at higher risk of burning. It is best to use waterproof sun cream because it is less likely to be sweated or washed off.
Putting your cream on
Firstly, you should put your sun cream on before you go in the sun. Then put on another layer to make sure you haven't missed any bits. Put it on before moisturiser, make up or insect repellent. It must go on before anything else so it is next to your skin.
Sun creams rub off. Even if they say they are waterproof, they may come off when you are swimming. In order to get the best protection, you must re-apply them often - at least every two hours. And more frequently if it is washed, rubbed or sweated off.
You must apply sun creams thickly. Nearly everyone puts them on much too thinly and so they don't get as much protection as is specified on the bottle. It is difficult to tell you how much to use on a website, but as the Aussies say, slap it on. You should be able to see and spread it very easily. If it all disappears as soon as you start rubbing it on, you haven't used enough. About a golf ball sized dollop should do for small children.
If your whole family only uses one bottle throughout a 2 week holiday, you definitely aren't putting it on thickly enough. We know it can be expensive, but if you aren't getting the protection you should, you are just wasting what you have spent. Better to buy more and put it on properly. As a fraction of your holiday cost, it really isn't very much.
Usually, the higher the SPF, the more the product costs. But we'd rather you used factor 15 than were put off altogether by the cost of the higher factor creams and lotions.