Most people are aware that in order to protect ourselves from sun damage, we need to wear a sunscreen. However there is so many options out there it’s hard to know what one to go for. We put together some important information to help to guide you.
WHAT IS UVA AND UVB?
UV radiation from the sun is transmitted in three wavelengths – UVA, UVB and UVC. UVC does not penetrate the earth’s atmosphere, so we only really need to protect against UVA and UVB.
UV irradiation in the form of UVA is associated with skin ageing. UVA affects the elastin in the skin and leads to wrinkles and sun-induced skin ageing (for example coarse wrinkles, leathery skin and brown pigmentation), as well as skin cancer. UVA can penetrate window glass and penetrates the skin more deeply than UVB. UVA protection in a sunscreen will help defend the skin against photo ageing and potentially skin cancer.
UVB is the form of UV irradiation most responsible for sunburn and has strong links to malignant melanoma and basal cell carcinoma risk (types of skin cancer). A sunscreen with a high SPF (sun protection factor) will help block UVB rays and prevent the skin from burning, and by extension damage that can cause skin cancer.
WHAT IS SPF?
SPF means sun protection factor It measures the level of UVB protection a sun protection product will give you and ranges from 1 – 90.
HOW DOES SPF WORK?
The SPF indicates the length of time that your skin is protected from sunburn, depending on your skin type.
To help you understand a bit better, if you start getting sunburned after five minutes in the sun without any sunscreen, applying a sunscreen with an SPF of 30 would protect you for 30 x five minutes (or 150 minutes) before you begin to burn.
Depending on your skin type, location and the time of year, the time it takes for you to begin getting burned is between five to 30 minutes, on average.
A high SPF extends the amount of time you can spend in the sun while protecting your skin. SPFs are broken down into four levels:
- Low (4, 6, 8, 10)
- Medium or Moderate (15, 20, 25)
- High (30, 40, 50)
- Very high (50+)
No sunscreen can block all UVB rays. However, in terms of percentages, a sunscreen with:
It’s important when selecting a sunscreen that it now only is an SPF that protects from UVB but also has a UVA rating which indicates the level of protection from UVA
When you currently buy sunscreen containing UVA protection in the UK you may notice a UVA star rating on the packaging. The stars range from 0 to 5 and indicate the percentage of UVA radiation absorbed by the sunscreen in comparison to UVB, in other words the ratio between the level of protection afforded by the UVA protection and the UVB protection.
Its important to choose a high SPF as well as a high UVA protection (e.g. a high number of stars). Sunscreens that offer both UVA and UVB protection are sometimes called ‘broad spectrum’. A sunscreen with an SPF of 30 and a UVA rating of 4 or 5 stars is generally considered as a good standard of sun protection.