Sunscreens and how they work, as the summer rolls in, it is important to remember to protect ourselves from the sun as well as enjoy it. The sun sends out ultraviolet radiation, more often referred to as UV rays, which can cause sunburn and other skin damage.
There are various types of UV rays, but the ones that you should be concerned about when shopping for sunscreens are UVA and UVB. UVA accounts for 95% of ultraviolet radiation that reaches the earth’s surface. UVA rays are associated with skin aging. The other UV rays can be split into UVB and UVC. UVC do not pose a large risk to us as it does not penetrate deep into the skin, and the majority of the rays are absorbed by the earths atmosphere and ozone. UVB does pose a risk to our health and is associated with skin burning.
Sunscreens are separated into two categories, chemical or physical. This separation is based on the protective filters found within the sunscreen product. Chemical filters absorb the UV rays and stop the UV from reaching your skin. Physical filters reflect the UV rays back into the atmosphere away from your skin. Both chemical and physical sunscreens offer protection against the sun.
The Live Well section of the NHS website recommends that the sunscreen you buy should be at least sun protection factor (SPF) 30 or above with at least a 4-star UVA protection rating. The SPF factor refers to the protection the sunscreen offers against UVB rays. The NHS also recommends that you stay inside or in the shade during the height of the sun (11am to 3pm). Sunscreen should be applied liberally and frequently, according to the manufacturer’s instructions. A tan does not protect your skin from the sun, and you should apply sun screen continuously whether you have developed a tan or not.
For NHS guidance on sunscreen, please follow the link below:
Sunscreen and sun safety
https://www.nhs.uk/live-well/seasonal-health/sunscreen-and-sun-safety/
For more information on the science behind sunscreens, please read the article linked:
The efficacy and safety of sunscreen use for the prevention of skin cancer