February 09, 2023
What do sun protection factor (SPF) ratings really mean?
We all know that using sunscreen is essential to protect our skin from the negative effects of excessive sun exposure. Awareness of the risk of skin cancer and the desire to prevent the appearance of premature signs of aging has made us all more conscious of protecting ourselves against the sun's UV rays. However, the SPF levels assigned to each sunscreen product can be a source of confusion.
It's essential to know exactly what you're buying so that you are aware of the level of protection you are getting, so here's our easy guide to understanding SPF.
What is SPF?
SPF stands for 'Sun Protection Factor,' and it's a number that indicates the level of protection a sunscreen product provides against ultraviolet, or UV, rays. Technically, it is a measure of the time a product can keep your skin safe from sun damage.
The SPF factor generally aims to inform us about the level of protection against UVB rays, however, in recent years, more attention has been paid to the impact of UVA rays.
UVA vs UVB Rays
The sun produces two types of ultraviolet rays; UVA and UVB rays. UVB rays are the most discussed. They tend to affect the outer layers of the skin, known as the epidermis. UVB rays are the cause of superficial sunburns and many types of skin cancer that can be linked to sun damage, such as melanoma.
UVA rays can penetrate much deeper into the dermis, the lower level of the skin. These rays are the source of the sought-after tan but are also associated with the development of lines, wrinkles, and signs of aging. They can also cause other varieties of skin cancer.
How the SPF Scale Works
The SPF scale aims to tell you how long a product can protect against the sun's ultraviolet rays, specifically UVB rays, so the factor should tell you how many times longer you will be protected compared to if you wore no sunscreen at all.
For example, if you wear a sunscreen with SPF 30, you would expect to have 30 times more protection than if you wore none, and it would take 30 times longer to burn. An SPF 50 sunscreen only allows 2% of UVB rays to penetrate the skin, compared to an SPF 30 product, which can let through 3% of UVB rays, meaning 50% more damaging UV rays can reach your skin with less factor.
On some sunscreen products, you may find a star-based rating. Star ratings relate to the proportion of UVA absorbed compared to UVB. So, products with a 5-star rating have the same level of UVA and UVB protection.
Which is the best SPF for me?
The best sunscreens and SPF products are those with broad-spectrum protection, meaning they protect against both UVA and UVB rays. Products with this quality are usually labeled to specify that they offer broad or full-spectrum protection.
SPF products come in several different forms; creams, lotions, oils, and sprays, to name just a few, so you can choose which type of sun protection best suits your needs. For those with dry skin, a moisturizing SPF lotion or cream will provide their skin with the moisture it needs, while for those looking for a silky, luxurious feel, an oil might be their preferred option. The most important thing to know is that the type of product you choose will not change the level of sun protection it provides; so an SPF 30 sunscreen will protect you from sun damage to the same extent as a spray with the same factor.
It's essential to know exactly what you're buying so that you are aware of the level of protection you are getting, so here's our easy guide to understanding SPF.
What is SPF?
SPF stands for 'Sun Protection Factor,' and it's a number that indicates the level of protection a sunscreen product provides against ultraviolet, or UV, rays. Technically, it is a measure of the time a product can keep your skin safe from sun damage.
The SPF factor generally aims to inform us about the level of protection against UVB rays, however, in recent years, more attention has been paid to the impact of UVA rays.
UVA vs UVB Rays
The sun produces two types of ultraviolet rays; UVA and UVB rays. UVB rays are the most discussed. They tend to affect the outer layers of the skin, known as the epidermis. UVB rays are the cause of superficial sunburns and many types of skin cancer that can be linked to sun damage, such as melanoma.
UVA rays can penetrate much deeper into the dermis, the lower level of the skin. These rays are the source of the sought-after tan but are also associated with the development of lines, wrinkles, and signs of aging. They can also cause other varieties of skin cancer.
How the SPF Scale Works
The SPF scale aims to tell you how long a product can protect against the sun's ultraviolet rays, specifically UVB rays, so the factor should tell you how many times longer you will be protected compared to if you wore no sunscreen at all.
For example, if you wear a sunscreen with SPF 30, you would expect to have 30 times more protection than if you wore none, and it would take 30 times longer to burn. An SPF 50 sunscreen only allows 2% of UVB rays to penetrate the skin, compared to an SPF 30 product, which can let through 3% of UVB rays, meaning 50% more damaging UV rays can reach your skin with less factor.
On some sunscreen products, you may find a star-based rating. Star ratings relate to the proportion of UVA absorbed compared to UVB. So, products with a 5-star rating have the same level of UVA and UVB protection.
Which is the best SPF for me?
The best sunscreens and SPF products are those with broad-spectrum protection, meaning they protect against both UVA and UVB rays. Products with this quality are usually labeled to specify that they offer broad or full-spectrum protection.
SPF products come in several different forms; creams, lotions, oils, and sprays, to name just a few, so you can choose which type of sun protection best suits your needs. For those with dry skin, a moisturizing SPF lotion or cream will provide their skin with the moisture it needs, while for those looking for a silky, luxurious feel, an oil might be their preferred option. The most important thing to know is that the type of product you choose will not change the level of sun protection it provides; so an SPF 30 sunscreen will protect you from sun damage to the same extent as a spray with the same factor.
