What does UPF mean?
When we use the term UPF on the website, it is an abbreviation of "Ultraviolet Protection Factor".
UPF therefore says something about how much the product protects against the sun's UV/ultraviolet rays.
It is these rays from the sun which tan the skin, but which also both damage and can burn the skin. Children in particular, who have finer and more sensitive skin than adults, should not stay in the sun without being covered or otherwise protected.
Summer hats are a great way to protect the little ones, and at mpDenmark they are labeled with UPF50. The summer hats have either received a special treatment/impregnation on the surface of the fabric or are produced by a fabric with a weave that makes the hat possess UPF50. The fabric used for the production of our summer hats have therefore been sent for testing for UV radiation, where they have achieved UPF50 protection.
What does the number mean?
UPF usually has a number after it, for example on this site, where we use UPF50, and this means that every time 50 rays from the sun hit the fabric of our summer hats, there is 1 ray that penetrates. Likewise, if a product has UPF20, 1 ray penetrates for every 20 rays. The higher the number, the greater the protection.
You can easily calculate it yourself that UPF50 protects against 98% of the sun's rays.
You can, since at 50 rays, 1 penetrates, which means that at 100 rays, 2 rays penetrate. Thus, 2% of the sun's rays penetrate, which means that the remaining 98% is blocked. That is a really good protection.
What is the difference between SPF and UPF?
Many people are probably familiar with the term SPF, which is an abbreviation of "Sun Protection Factor". It is this designation that we see on sunscreen. SPF is a standard used to measure the effectiveness of sunscreen. Here it is calculated in a different way. It is said that SPF30, for example, extends the time it takes for you to get sunburned by 30 times. SPF15 extends the time by 15 times, etc. It is therefore an expression of how much longer you can stay in the sun without getting sunburned compared to if you did not wear sunscreen.
SPF is also said to only protect against the sun's rays called UVB (unless anything else is written on the product), whereas UPF protects against both the sun's UVA and UVB rays.
If you bathe/sweat, the SPF/sunscreen will be washed off your skin, and protection therefore depends on applying new layers to get the full effect. The UPF in mpDenmark's hats is not easily washed off, and not at all if it concerns the fabric's weave. You can therefore count on the protection even after a lot of use.