How should I use sunscreen?

Sunscreen explained 

Sunscreen explained

  • Prevents UV radiation reaching the skin
  • UVB (ultraviolet radiation) causes sunburn (and also enables vitamin D production)
  • UVA causes wrinkles, brown spots (photoageing)
  • Both UVB and UVA can contribute to the development of skin cancer
  • SPF = Sun Protection Factor (the number of times longer you can stay in the sun before burning compared to wearing no sunscreen) indicates UVB protection
  • The amount of UVB radiation that is filtered out varies with different SPFs:
    - SPF 15 blocks 93% of UVB;
    - SPF 30 blocks 96.7% of UVB;
    - SPF 50 blocks 98.3% of UVB.
  • Always check a product has UVA protection. It is not essential to have the Boots star rating, but if it has, look for 4 or 5 stars. The UVA in a circle is a marker of quality and indicates that the UV protection, specifically the critical wavelength, extends beyond 370nm.
  • The critical wavelength (CW) is the point at which 90% of the absorption of UV takes place. 370nm is accepted as a minimum standard worldwide.
  • Water resistant sunscreens are ideal for sports and outdoor activities

Questions? Have a look at the FAQs

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