SPF stands for sun protection factor, and it is a measure of the amount of ultraviolet B radiation (UVB) protection.
The number on the suncream bottle indicates the length of time it would take for UV to burn your skin compared to no sun cream at all.
Of course, this depends on the cream being applied exactly as the bottle instructs.
It would take 20 minutes to burn in midday sun without suncream on. If you apply factor 15 it will take four hours for you to turn red, which is 15 times as long.
Suncream should be worn whenever the daily Ultraviolet index (UV index) is above two, and it definitely is this week.
The UV index is an international standard measurement of the strength of sunburn-producing UV radiation at a particular place and time.
UVB rays are the main cause of sunburn and skin cancer, so it is important to protect yourself from them every day.
UVB rays vary in wavelength and intensity at different times of the day, and they also affect people differently.
They damage the skin’s epidermis, also known as the outer layer. This is where the most common skin cancers occur.
Melanoma, an aggressive form of skin cancer, may also be caused by a short but intense exposure to UVB.