What is SPF?
It refers to the SPF (Sun Protector Factor) or in Portuguese FPS , Solar Protection Factor which is a factor related to protection against UVB rays and which allows you to increase the time of sun exposure without suffering a burn. For example, if 5 minutes is the time it takes for a person with a low phototype to get solar erythema, that is, red, an SPF 30 multiplies that time by 30 times , that is, it would take 150 minutes, two and a half hours. In practice, this is not the case, as the protector should be applied in a generous amount and in a uniform layer. The amount to apply should be 2mg of protector per cm2 of skin, which is equivalent to 1 teaspoon for the face or 3 fingers and a golf ball for the body. The SPF is universal and complies with ISO standards, with an SPF 50 expected to provide the same degree of protection whether in Europe, Asia or America.
There are 4 levels of protection:
- Low (SPF 6 to 10)
- Medium (SPF 15 to 25)
- High (from 30 to 50)
- Very High (50+)
We recommend using High from 30 to 50 or Very High, 50+.
The protector should still be reapplied every 2 hours , after bathing or drying with a towel and after intense perspiration. Do not forget that UVB radiation is responsible for burns and tans, allergic reactions and skin cancer.
What is PPD (Persistent Pigment Darkening)?
The protection factor against UVA radiation is given by the PPD factor, which is generally not mentioned on sunscreen packaging. The European Union recommends that it be at least 1/3 of the SPF – in an SPSF 30 protection against UVA rays would be at least 10. When sunscreens meet this requirement, they display the UVA symbol inside a circle.
Protection against UVA radiation is very important because it is responsible for photoaging (changes in collagen and elastin fibers, wrinkles, sagging), sun intolerance and skin pigmentation (melasma, dark spots).
What are filters?
Filters are the physical or chemical substances present in sunscreens that are responsible for their protective power against radiation and that are present in the formulations in addition to excipients such as water and other actives such as hyaluronic acid, niacinamide, antioxidants and others.
What are the differences between chemical and physical filters?
Chemical filters (Octocrylene, Avobenzone, Octinoxate, Oxybenzone, Hemosalate, Tinosorb, Meroxyl):
- absorb radiation, modify it and emit it back
- have greater spectrum of protection UNV in addition to UVB
- allow to formulate sunscreens that are more fluid, transparent and without white residue
- may have greater irritant potential.
Physical filters (Titanium Dioxide, Zinc Oxide):
- absorb radiation, emit it, and reflect some of it
- have broad spectrum UVB protection
- can leave white residue and thicker protectors.
Are mineral protectors better than physical ones?
The answer is it depends : physical filters should be preferred in babies up to 1 year of age, in some specific cases such as very sensitive and reactive skin and sportsmen. However, most chemical filters can be used safely without the risk of causing allergic reactions and allow for more fluid, transparent and residue-free formulations and with a greater spectrum of UVA protection. The misconception that physical filters are “inert” and safer on sensitive skin has emerged in the US because, as they have few chemical filters approved by the FDA (they are in the 90s compared to Europe), and, one of them being Avobenzone, which is one of the most sensitizing, they are often recommended to the detriment of chemical filters. In Europe we can safely opt for the best of both worlds and use protectors with physical and chemical filters.
How to choose sunscreen:
When choosing a protector, several factors must be taken into account, such as:
- have broad spectrum UVB, UVA, IR, HEV, Blue Light protection
- be water resistant
- have good ophthalmic tolerance (do not irritate the eyes)
- have enough capacity for the time of application (holidays, the whole family)
- contain antioxidant and repairing actives in the formula
- be correct for that circumstance (practicing water sports, daily use)
- be directed to a given stage of life (babies, children)
And remember that the best protector for you has to be one that you love , since, in the case of your face, you'll use it every day. It should therefore be sensorially pleasant and have a smell, texture and finish that you like and leave the skin comfortable so that you want to put it on every day.
Can body protectors be used on the face?
In theory yes, but, and since the skin of the face and body have different characteristics, it should be possible to use two different ones . In addition, face shields can be colored and are generally less greasy, formulated with milder ingredients and without added perfume. They are also useful in cases of special needs or pathologies such as acne, rosacea, stains, wrinkles, sensitive eyes.
Can I use last year's sunscreen?
Again, it depends. If it is unopened, within the expiry date and stored away from high temperatures and humidity – yes. If it has already been used, check that it is within the period and period after opening (PPA) that appears on the packaging with the symbol of an open jar and the indication of the months (generally from 6 months to 12 months), if it was well stored and if it does not show changes in smell, color, texture and consistency. It should also be rejected if you notice that your skin turns red in a short time (there may have been a change in the filters with a loss of effectiveness).
How to store sunscreen?
Store in a cool, dry place (the fridge and bathroom won't do), at room temperature and away from direct sunlight. Do not leave it in the sun on the towel, close it tightly and place it in the shade. Avoid leaving it in the car in the heat to avoid changing the filters.
What does it mean to be water resistant?
Being water resistant means staying effective for 40 minutes on wet skin and being very water resistant means staying effective for 80 minutes . The very water-resistant ones should be preferred by children and athletes. In real conditions, with salt water, with chlorine or in the waves, they may not maintain the same effectiveness time as that obtained in the tests. No protector is 100% effective and resistant in real conditions, some loss of effectiveness always occurs with water or sweat.
If I use sunscreen can I be exposed to the sun as long as I want?
No , you should only be exposed to the sun when you can't avoid it, such as bathing, drying yourself and being in the shade whenever possible. You should also take extra care, such as wearing a wide-brimmed hat or cap, sunglasses , dark clothing (t-shirt), also protecting your lips (balms or lip sticks with SPF), ears and the back of your hands and feet. Also avoid exposure between 12 noon and 4 pm or at low phototypes between 11 am and 5 pm . Do not frequent tanning beds.
When do I not need to use sunscreen?
No need to use sunscreen:
- at night
- in the shower
- in a cave. 😄
