The Sun Protection Factor (SPF) is a measure of how long you can expose yourself to the sun with sunscreen without getting burned. It indicates how much longer you can stay in the sun with sunscreen without getting a sunburn, compared to using no protection at all. To evaluate the sun protection factor, the COLIPA International Sun Protection Factor Test Method is used, which calculates the minimum erythema dose (MED) after applying sunscreen in a standardized manner.
The Sun Protection Factor (SPF) is a measure of how well a sunscreen protects against UV radiation. This primarily refers to the UV-B component of sunlight. Sunscreens must also protect us from UV-A light to prevent other light-induced skin damage. As a result, since 2006, sunscreens in Europe must meet minimum standards for efficacy against both UV-B and UV-A radiation:
- Sun Protection Factor (SPF): Sunscreens with an SPF of 6 or higher are optimal for protecting your skin from harmful sun rays.
- UV-A Protection Factor (UV-A-PF): The UV-A protection factor must be at least one-third of the sun protection factor.
A sunscreen with an SPF of 30 should have a UV-A protection factor (UV-A-PF) of at least 10. COLIPA has issued a recommendation for in-vitro testing to determine the UV-A protection factor. The symbol indicating compliance with the required UVA protection is on the packaging and consists of a circle with the letter combination "UVA".
Which Sun Protection Factor do I need?
Every person reacts differently to the sun. There are various skin types based on the color of the skin, hair, and eyes. Additionally, each skin type requires a unique self-defense time.
Skin Type 1
These skin types have reddish-blonde hair, light eyes, a very fair complexion, and many freckles. They always get sunburned and never tan. The self-protection time is 3 to 10 minutes in the sun.
Skin Type 2
Blonde hair, light eyes, pale skin, often with freckles, and almost always prone to sunburn. The self-protection time is 10-20 minutes.
Skin Type 3
People with dark blonde to brown hair, a medium complexion, and light or dark eyes usually tan slowly but well. They also sometimes get a light sunburn and have 20-30 minutes of self-protection time in the sun.
Skin Type 4
Hair: dark brown or black, skin color: dark, eyes: dark, sunburn is unusual, always tans. The self-protection time is usually 30 to 45 minutes.
Skin Type 5
Black hair, dark complexion, dark eyes, very rarely gets sunburned, always and quickly tans. The self-protection time is 45-60 minutes.
Skin Type 6
These skin types have black hair, a very dark complexion, and dark to black eyes. They very rarely get sunburned and have very insensitive skin. The self-protection time is 60 to 90 minutes.
How is the Sun Protection Factor calculated?
You can roughly calculate your sun protection factor and the maximum time you can be exposed to the sun daily. To do this, multiply your sun protection factor by your natural self-protection time. This is the time you can spend in the sun without harming your skin. It is determined by your individual skin type.
For example, a person with skin type 2 has a natural self-protection time of about 10 to 20 minutes. With a sunscreen with SPF 20, this would theoretically mean you could stay in the sun for 200 to 400 minutes (i.e., about three to seven hours).
However, the German Federal Office for Radiation Protection advises only using 60 percent of the calculated protection time for sun exposure. Even if a sun protection factor of 50 or 100 is present, a residual amount of UV radiation still penetrates the skin and causes permanent damage to the skin, which can lead to cancer.
Which SPF is recommended according to skin type?
Depending on your skin type, you should use the appropriate level of protection:
Light protection: SPF 6 to 10
Medium protection: SPF 15 to 20
High protection: SPF 30 to 50
Very high protection: SPF 50+
The different filters in sunscreens
The aforementioned UVA and UVB filters prevent UV radiation from penetrating your skin, which would otherwise cause damage. Therefore, a distinction is made between two types of filters:
Mineral UV filters
Titanium dioxide and zinc oxide are two types of mineral UV filters. They reflect UV radiation and protect the skin from sunburn.
Organic UV filters
Organic UV filters absorb UV radiation and convert it into heat.
In sun protection products, these UV filters are combined to achieve the required UV protection factor. The higher the proportion of filters in the mixture, the better.
What to look for in face cream with SPF?
It is better for your skin if you can gradually accustom it to the sun: so, as the first step in your morning routine in the bathroom, apply sunscreen – because in spring, the sun is already quite high in the sky. Since our skin is no longer accustomed to such high radiation due to winter, it must eventually adapt. It takes some time for melanin production to begin absorbing UV rays that would otherwise penetrate deeper into our skin and damage our cells if we were in the sun without sunscreen. Only those who use sunscreen every day can avoid wrinkles and pigment disorders.
Sun damage becomes visible at the earliest after five to ten years. Therefore, it is important that we use day creams with at least SPF 15 in everyday life. This protects us from radiation exposure during short moments in the sun. However, you should not overestimate this protection. A sunscreen with a high sun protection factor (SPF) is required if you are exposed to the sun for a long time. Sun protection filters are stronger in this form of products due to the different components. To prevent sun damage, it is important to apply sunscreen to all skin exposed to the sun – not just your face. Make sure to also apply it to often overlooked areas such as your ears, neck, hands, arms, legs, and scalp.
Facts about the Sun Protection Factor
- You will also tan with sunscreen and in the shade, it just happens a little slower.
- Children's skin is sensitive, so it is important to use sunscreens with a high sun protection factor. In addition to chemical filters, mineral filters also provide good sun protection for children.
- A loose, white T-shirt offers sun protection of at least SPF 10, while a black T-shirt even offers 15. If the shirt is tight or wet, the UV protection decreases.
- There is also clothing that offers UV protection, which is particularly useful for outdoor activities in the sun.
- The intensity of solar radiation increases by about 10% per 1000 meters of altitude above sea level.
How do I choose the right sunscreen?
The following tips will help you with the correct selection and application of sunscreens:
- The sunscreen provides adequate sun protection.
- The BfS recommends that children use sunscreens with an SPF of 30 or higher, and adults should use sunscreens with an SPF of 20 or higher. If you spend extended periods at high altitudes, near snow, in water, or generally in the sun, you should opt for a sunscreen with a very high SPF (50+).
- The sunscreen also protects you from UV-A radiation.
- The UV-A protection is clearly indicated on the product.
- A list of ingredients is available.
- If you are hypersensitive to the ingredients in sunscreens, you should consider this when choosing a sunscreen.
- Make sure to apply sunscreen before going outside.
- Applying sunscreen 20-30 minutes before sun exposure guarantees full protection.
- A sufficient amount of sunscreen is applied.
- For five full-body applications, you should use 200 ml of sunscreen.
- It is reapplied regularly.
- Be sure to reapply sunscreen every two hours, especially after swimming or towel drying.
