What does SPF measure for creams? It’s probably not what you thought

The summer season in the northern hemisphere is ready. Spring is not over yet, but the temperature is already suitable for visiting the beach or active recreation. At least they accompany you intermittently. It’s time to remember the importance sunscreen and, by the way, refute some hoaxes, such as, for example, the SPF value.

These are English abbreviations “sun protection factor” As the name suggests, it indicates the degree of protection that the defender gives us. This is clear to all of us. The higher the SPF, the more reliable.

However, it is often said that SPF refers to time when we will protected when using a protector, although this actually applies to amount of sun exposure. Let’s see this with some examples.

True SPF Definition

SZF refers, on the one hand, to amount of solar energy which can be applied to protected skin without causing burns compared to the amount required for unprotected skin.

This is measured not by time, but by percentage. For example, with SPF 30Only one-thirtieth of solar radiation passes through the skin. This means 3.3%. Instead with SPF 50, only one fiftieth will do it. That is 2%. Neither 3.3% nor 2% will initially cause burns. However, over time, they may be able to do this through savings.

So why can’t we talk about time?

Given the percentage question, we could do some calculations to see how long it would take for the burns to appear. If only 2% of radiation penetrates, then the time will be longer, logically. However, accurate calculations are impossible because the amount of solar radiation is not always the same. This largely depends on the geographical location and the clarity of the sky, but even in the same place the amount of sunlight changes within an hour.

According to the US FDA, the amount of solar radiation passing through our skin in 1 hour at 9 am can be equivalent to that passing through in just 15 minutes at 1 pm. For this reason, the time cannot be calculated accurately. In fact, we can burn faster with SPF 50 in the afternoon than with SPF 30 in the morning.

What should the ideal SPF be?

Experts recommend always using an SPF of 30 or 50. Below this level, the level of protection is significantly lower. For example, at SPF 15, 6% of radiation can pass through the skin, and this, although it may not seem like much, is actually a lot compared to higher SPFs.

Despite this, dark-skinned people Perhaps they can afford a lower SPF. This is because the pigment that gives skin color, called melanin, is responsible for absorbing solar radiation so that it does not reach the cells of the dermis. If this type of natural barrier already existed, a high SPF would not be so necessary. This also greatly affects age. Children and older adults have thinner and more sensitive skin, so it is important that they always use a high SPF level, ideally 50.

Of course, whatever we use is important. replenish approximately every 2 hours. And SPF can help us stay burn-free longer, but sunscreen degrades over time, especially if we sweat, rub, or get wet. It’s important to replenish it regularly, no matter what your SPF is.

In this way we can enjoy the Sun in health. Because the radiation from the royal star is very necessary; but like many things in life, only in the right way.