Fun in the sun

While it's now accepted that exposure to the sun can cause permanent skin damage, it's not always easy to decide exactly what you should be doing about it.

Some sun creams claim to be waterproof, others don't have oil and a few claim to offer wearers shimmery skin while protecting them - so how do you know which one to choose?

When people burn, they're actually reacting to the ultra-violet (UV) radiation emitted by the sun. In all, there are three types of UV radiation: UVA, UVB and UVC. While UVC is absorbed by the earth's atmosphere, UVA and UVB rays are the ones to worry about. UVA rays can cause cause long-term skin damage and premature skin ageing, while UVB rays cause sunburn.

Mike Brown, senior scientist for Boots Suncare, says, "The first and most important thing is to be sensible in your choice of SPF (Sun Protection Factor). Ensure it is appropriately high enough for your skin type, is a brand you trust and has a 5-star UVA star rating. This will ensure you're getting as much protection from UVA rays as UVB rays."

When calculating how good a product will be at preventing sunburn, shoppers needs to take into account its SPF, or Sun Protection Factor i.e. protecting you against UVB rays. The higher the number, the greater the protection and the less likely you are to burn.

The EU Commission has grouped Sun Protection Factors into four categories: low (SPF 6-10), medium (SPF 15, 20 and 25), high (SPF 30 and 50) and very high (SPF 50+).

According to experts, when choosing your SPF, it's important to consider skin type. Bevis Man, of the British Skin Foundation (www.britishskinfoundation.org.uk), says that this can range from type 1 (fair skin and never tan) through to type 6 (black and dark Asian skin).

"Those with type 1 skin should use SPF 50 as they are at the highest risk of sunburn and subsequently the risk of skin cancer," he says.

You should also consider where you're going on holiday, what time of year it is and how accustomed your skin is to the sun. "If you're particularly active, you may need to use a higher SPF to allow for wash-off from perspiration or abrasion," Mike Brown advises.

While officially there's no difference between using a protective spray, roll-on or tube of cream (an SPF 15 spray will offer the same level of protection as an SPF 15 lotion), it's worth thinking practically about application.

"The SPF is influenced by the amount of product you apply," says Brown. "Since sprays tend to be light and easy to apply, you have to be careful not to under-apply and end up with reduced protection."

Check the back of your cream before using it, to confirm its PAO (Period After Opening). This symbol can usually be found on the back of the bottle.

"This is the little picture of the open jar with a number on it, which dictates how long in months you can safely use the product before replacing it," says Man.

Factors such as heat and bacteria can also damage sun screen though, so if you're not sure if you should use a product, look at it: "It should appear bright and shiny with no seepage of any liquid (either watery or oily) and no separation of the product," says Brown. "It should also smell clean and fresh and of the original fragrance."

There's no such thing as a harmless amount of sun exposure. "Even small daily amounts of UV exposure contribute to photo-ageing and damage to the skin," says Dr. David Orentreich, Clinique's Guiding Dermatologist.

"In fact, it's now believed about 80 per cent of skin changes we perceive as 'ageing' are due to sun exposure. This is why daily sun protection is crucial all year long, regardless of season."

Tips on staying safe

1 Apply sun protection at least 20 minutes before exposure to the sun.

2 Three tablespoons of lotion are needed to cover the body. Remember to pay particular attention to the ears, nose, shoulders, chest and neck.

3 Reapply generously every two hours, and more frequently after exposure to water or perspiring.

4 Try to avoid the sun from 11am to 3pm when the sun's at its strongest.

5 Keep well hydrated by drinking lots of water and avoid alcohol.

6 Keep your face out of direct sunlight and use a higher SPF protection.