Sun Protection Factor (SPF)

Understanding SPF is simple. The higher the SPF number, the greater the protection the sunscreen will give.

SPF stands for Sun Protection Factor and is provided on-pack as a number. It is an indication of the amount of protection sunscreen provides against UVB rays. UVB rays penetrate the outer layer of the skin and damage the cells resulting in inflamed skin or sunburn.

The SPF number is easily recognisable as it is standardised throughout the UK, Europe and across most of the world. The higher the number, the greater the protection; but we shouldn't think of the SPF number as indicating multiples of the amount of time we could stay out in the sun without sunscreen before we burn. Sunsafe behaviour means we should not use sunscreen to stay in the sun longer.

The UV filters that provide the SPF in a sunscreen help to filter out UVB rays. An SPF of 15 will filter out approximately 93% of UVB rays and an SPF of 30 will filter out around 97%. While this might not seem like a big difference, it can have a significant improvement in sun protection for someone who burns easily.

Alongside the SPF number there will be an indication of the type of protection the sunscreen offers - i.e. low, medium, high or very high.

Find out more about SPF and sunscreens.