The low down on SPF.

 SPF is something that should be used all year round, however, looking for the perfect SPF can be a minefield. How much do you apply? How high a factor? What is broad spectrum? Chemical or physical? Well never fear! This is the ultimate guide.

Types of SPF: Chemical and physical

'Physical' sunscreen (occasionally marketed as 'natural') reflects UV light. However, it is a myth that it's 'natural' due to the ingredients used (zinc oxide and titanium dioxide.) Those mentioned have shown to be potentially toxic (yes, toxic) for fish and sealife. Furthermore, zinc oxide and titanium oxide aren't biodegradable and use nano-technology, which is being investigated by cancer research bodies because of its possible link to cancer in humans. Physical sunscreen sits on the surface of the skin and block and scatter UV rays.

The pros to physical SPF: Usually a lot thicker than their counterpart, physical sunscreens are easy to see where they've been applied and rubbed off, this ensures sensitive areas are covered. These can be less irritating for sensitive skin than chemical sunscreens.

The cons to physical SPF: Like mentioned before hand, there are some worries about physical SPF's and how safe they are for use. A physical sunscreen is often heavier and thicker on the skin, making it unsuitable for those with oily/acne-prone skin.

Traditionally, 'chemical' SPF's absorb the light. The vast majority of sunscreens found on pharmacy shelves fall into the chemical category. These SPF's contain active sun filters that penetrate the skin and absorb UV rays to prevent them from causing damage.

The pros to chemical SPF:  Chemical SPF's are able to provide highly effective protection. They can be formulated to be lightweight, have a non-sticky feel which is ideal for daily wear. 

The cons to chemical SPF: Some chemical UV filters have been known to cause allergic reactions and irritation when applied to sensitive skin. 

What factor should I be using?

Use either SPF30 or SPF50, nothing lower!

What to ask when you buy SPF: What is SPF? and Is it a Broad Spectrum Product?

There are two main effects from being in the sun: skin ageing and skin cancer.  You ideally need a broad spectrum SPF (something that provides proportional protection against UVA and UVB rays.) UVA rays (long wave) penetrate deep into the skin, gradually destroying elasticity thus causing premature ageing. UVB rays (short wave) causes skin damage (i.e. burning) and alter skin cell structure, which may lead to skin cancer. A tan is simply a sign of DNA damage. There's no such thing as a 'safe tan.'

Did you know? W.H.O have identified UV light as a human carcinogenic. 

'Those with darker skin don't need SPF'

Whilst darker skin tones are not as vulnerable to UV light because of their built-in SPF of 13.3, they still need protection from UV damage and should use a minimum of SPF30.

'SPF accumulates' 

If you wear a moisturiser, primer and sunscreen, you will only have the highest SPF that you are using. You can not 'add them up'

'What about products that have built in SPF?'

Researchers from the University of Liverpool stated only sun cream is recommended when spending long periods of time in the sun due to lack of thorough application. The team carried out a study in which they asked a group of participants to apply sun cream to their faces on the first day of testing, and then to apply moisturiser with SPF on another day. The researchers then took photographs of their faces on both days, using a specially modified camera that's able to see UV light. The darker the skin on their faces appeared in the photographs, the greater the level of protection. The team concluded that the participants covered 89 per cent of their faces when applying sun cream, and only 84 per cent of their faces when applying moisturiser with built in SPF.

The images where the participants used sun cream appeared darker, implying that people are more likely to apply sun cream more thickly than moisturiser, which will consequently provide their skin with a stronger defence from the sun.
Furthermore, a moisturiser containing SPF only protects you from UVB - it doesn't protect you from UVA. In short: you won't burn but you'll still get wrinkles. 

Here are some of my favourites

- La Roche- Posay Anthelios. 

- Ecooking

- Heliocare

- Zelens Daily Defence SPF30

Stay safe, apply sunscreen and have a wonderful day,

Sarah :)