How to properly use SPF in the city and on the beach – explains doctor and scientist Natalia Bobok

Daily sun protection is no longer a seasonal recommendation, but a basic step in skin care. It's not just about care, but also about preventing photoaging, pigmentation, and even cancer. However, even those who regularly use sunscreen often make mistakes: applying too thin a layer, choosing ineffective filters, ignoring key areas, or relying only on foundation with SPF.

How to choose a sunscreen, how to apply it correctly, and what to pay attention to in the composition – explains Natalia Bobok, Candidate of Medical Sciences, doctor, scientist, and founder of the Instytutum and Hyalual brands, especially for LIGA.net .

Which sunscreen is better for daily use in the city, and which one for the beach?

Natalia Bobok draws attention: urban conditions are significantly different from beach conditions, so the approach to choosing an SPF product should be different.

"For daily use in the city, I recommend choosing sunscreens based on new-generation organic filters – such as Tinosorb S (Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine), Ethylhexyl Triazone and Uvinul A Plus (Diethylamino Hydroxybenzoyl Hexyl Benzoate). These filters have high photostability, do not irritate even sensitive skin, do not accumulate in the body and provide reliable protection against both UVB and UVA rays. In urban conditions, when the skin is not exposed to excessive sweating or contact with water, such formulas do not require frequent renewal during the day," says the doctor.

According to the scientist, in addition to effectiveness, texture is also important for daily use.

The cream should be light, pleasant, not leave white marks, and blend comfortably with other skincare steps or makeup. Only then will SPF become a habit, not an obligation.

"For active recreation on the beach, you should choose sunscreen with the highest degree of protection (SPF 50 or higher), and be sure to reapply every 2 hours, especially after swimming or physical activity," she emphasized.

In both cases, Natalia Bobyk pays attention to the following parameters:

• SPF 50 provides more effective protection and allows you to compensate for possible application errors;
• The formula should be broad-spectrum – meaning it should protect against both UVB and UVA rays;
• The composition should include photostable, safe filters of the new generation, in particular Tinosorb S, Uvinul A Plus and Ethylhexyl Triazone.

Modern sunscreens contain additional ingredients to protect against blue light, infrared radiation, or aggressive environmental factors. This helps not only prevent burns, but also combat all the main signs of skin aging.

What is the key difference between city and beach SPF?

According to Natalia Bobok, it's not about the cream's composition, but about the frequency of renewal. In the city, your skin doesn't sweat excessively, you rarely come into contact with water or sand – so one layer of a quality product in the morning can protect throughout the day.

"During a beach vacation, protection is actively washed off by water, sweat, and rubbed off with a towel, sand, and clothing. Even if the packaging says "water-resistant," this is not a guarantee that the declared SPF will be maintained – it only means that the product will last 40–80 minutes in the water. Therefore, sunscreen should be reapplied every 2 hours on the beach and always after each swim."

Separately, you need to understand what the SPF 50 mark on the bottle means: it is not a percentage level of protection, but an index that shows how much longer the skin will be protected from UVB rays compared to unprotected skin. For example, SPF 50 blocks up to 98% of UVB radiation and allows you to stay in the sun 50 times longer without the risk of burning – if the product is applied correctly and in sufficient quantity. If it is applied too thinly or unevenly – the actual level of protection can decrease several times – to SPF 15-20. Therefore, I recommend choosing products with SPF 50, not lower," explains the scientist.

The difference is not in the composition, but in the frequency and correctness of application. And all the divisions into "SPF for the city" or "SPF for the beach" are more of a convenient marketing navigation than real differences. The main thing is to understand the context of use and handle the product correctly.

What areas are most often ignored when applying cream?

Scientist Natalia Bobok emphasizes that all areas exposed to direct sunlight and not covered by clothing need sun protection.

"Most often, people ignore applying SPF to their ears, neck, and décolleté area – although these are the areas that are exposed to active ultraviolet radiation in the summer, even in the city. And it is here that we often first notice signs of burns and photoaging: redness, dullness, pigmentation," says the doctor.

According to her, for sunscreen to really work, it's not just what you apply, but how much you apply .

"Take as a rule: one strip of cream the length of an index finger – for the entire face, another – for the neck, ears and décolleté. This amount corresponds to the standard by which SPF laboratory tests are conducted. And in urban conditions, if the product contains photostable filters, this application is enough for the whole day – without renewal," she added.

Do you need to apply SPF to your hands, legs, and other exposed parts of your body in the city if you spend most of your day in the office?

As Natalia Bobok explains, if an area of the body is exposed, not covered by clothing, and not in the shade, it needs protection. Even a morning walk, a trip to the bus, or a lunch break are times when the skin receives a dose of ultraviolet radiation.

"This is especially true in spring and summer, when we wear open clothes and easily underestimate the sun. Applying sunscreen to exposed areas is not about excess, but about consistent care. And when you follow the principle: "no shade or clothes – then you need cream", you are definitely on the side of the health of your skin.

By the way, "use SPF" is more of a colloquial phrase, because it is correct to say "sunscreen" or "sunscreen cream." SPF is an abbreviation for Sun Protection Factor, which means "sun protection factor" and indicates the ability of the product to protect the skin from ultraviolet rays," the doctor noted.

How often should you reapply sunscreen in the city and at the beach? Is there a difference between chemical and physical filters in this sense?

"Physical filters (zinc oxide, titanium dioxide) work like an "unstable mirror" on the surface of the skin – and that is why they are easily erased. Their protection is broken when touched, when wearing glasses, hats, clothes, or simply when you touch your face. Therefore, such products need to be renewed every 2 hours, regardless of where you are – in the city or on the beach.

"New generation chemical or organic filters (e.g. Tinosorb S, Uvinul A Plus, Ethylhexyl Triazone) slightly penetrate the upper layer of the skin and remain photostable throughout the day. In urban conditions, if there is no heavy sweating, contact with water, or active physical activity, such protection may not need to be renewed – one full application in the morning is enough," explains Natalia Bobok.

However, as the scientist noted, if you are actively moving, sweating, swimming or toweling off, even the most resistant filters need to be renewed. In such conditions, it is worth renewing the sunscreen every 2 hours or after each swim – this is how you can maintain the effectiveness of the declared SPF.

How to properly combine SPF with makeup?

According to Natalia Bobok, sunscreen is always applied as the last step of care – before makeup. If its texture is light and comfortable, it goes well with foundations, does not affect the durability or weight down makeup, while fully protecting the skin.

"I always recommend choosing SPF formulas that provide long-lasting protection without the need for reapplication in urban conditions. However, in the case of active recreation on the beach or playing sports – when reapplication is mandatory – it is better to refrain from applying foundation. In direct sunlight and when sweating, it creates an additional burden on the skin," she says.

Natalia Bobok also draws attention to the fact that there are indeed foundations and powders with SPF50 sunscreen on the market, but it is important to understand: for them to truly provide the claimed protection, they need to be applied very thickly and evenly, just like a regular SPF cream.

"In the case of decorative products, this is not practical and not comfortable – especially in the heat or at sea. If you apply them, as usual – in a thin layer – they do not protect the skin at the SPF50 level, as promised on the packaging, and the actual level is approximately SPF15-20, that is, they only create the illusion of safety.

In addition, decorative cosmetics with SPF usually contain only UVB filters that protect against burns, but do not have sufficient protection against UVA rays, which are responsible for photoaging and deeper damage.

"In addition, there is evidence that inhaling some powdered sunscreens (in powder or spray format) can be potentially harmful to health. Therefore, such products are more likely to be used as additional protection or a temporary solution, but not as the basis for daily skin protection," the doctor added.

Can sunscreen clog pores? How to avoid rashes when using SPF products?

Sunscreen shouldn't cause rashes if it's dermatologically tested, contains non-comedogenic ingredients, and is suitable for your skin type.

However, as Natalia Bobok emphasizes, even the best cream can clog pores if it is not washed off properly. This is especially true for waterproof or thick textures, so it is important to use a two-step cleansing in the evening:

"First, you need to dissolve the sunscreen formula, sebum, and makeup using hydrophilic oil. Then, wash with a delicate cleansing gel to completely wash away the remaining product, dirt, and sebum. This approach helps to avoid clogged pores, inflammation, and keep the skin's microbiome in a healthy balance."

How to choose the right sunscreen for different skin types – oily, dry, combination?

Basic care should correspond to your skin condition, the problem you want to solve, and the expected result. But sunscreen is primarily about reliable protection against ultraviolet rays.

"If you choose a formula with stable organic filters and a light, comfortable texture, it will be universal and suitable for most skin types. An additional plus is the presence of care components in the composition. Moisturizing complexes, antioxidants, anti-pigmentation components, vitamins and peptides can enhance the effect of your daily care, but do not replace it.

As for separate products for the face and body, this is not a prerequisite. You can apply your face cream to exposed areas of the body. However, this is not always convenient: the body has a much larger area, and the volume of the bottle will run out faster. Therefore, in practice, it is often more convenient to have two products – for the face and for the body – with a similar level of protection and filters," says Natilia Bobok.

Common mistakes when using SPF

Even those who regularly use SPF often make several common mistakes that reduce the effectiveness of protection. Natalia Bobok names a few main ones:

• Too thin a layer. For SPF 50 to really work, you need to apply it generously – about 1/4 teaspoon on your face.
• Using outdated filters that can irritate the skin or be hormone disruptors.

"Such filters can lose their effectiveness in the sun or cause irritation. Instead, modern, new-generation organic filters provide stable, broad protection without harming the skin."

• Counting on a foundation with SPF doesn't work as basic protection.

"Foundations or powders may indeed contain sunscreens, but they are applied in too thin a layer to have a real effect. In addition, they do not cover the entire surface of the face, do not protect the ears, neck, or area around the eyes. Therefore, it is more of a pleasant addition than an alternative to full sun protection," says the doctor.

• Ignoring the ear, neck, and décolleté areas is one of the first to age.

What parameters do you recommend paying attention to when choosing a sunscreen?

When choosing a sunscreen, Natalia Bobok advises paying attention not only to the SPF number, but also to the quality of the formula as a whole. Here are the key parameters that really matter:

1. Broad spectrum protection. The product should protect against both UVB rays (burns) and UVA rays (aging, pigmentation, risk of mutations). This should be labeled as broad spectrum or PA++++.

2. New generation photostable filters . The most modern, safe and effective components:

• Tinosorb S (Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine)
• Uvinul A Plus (Diethylamino Hydroxybenzoyl Hexyl Benzoate)
• Ethylhexyl Triazone

They do not irritate the skin, do not penetrate into deep layers, do not break down under the influence of the sun, and do not harm the environment.

3. Avoid filters that may be unsafe or outdated. These include:

• Oxybenzone
• Cinoxate
• Dioxybenzone
• Ensulizole
• Meradimate
• Homosalate
• Octinoxate
• Avobenzone
• Octisalate
• Octocrylene
• Padimate O
• Sulisobenzone

These substances are absorbed through the skin and accumulate in the body, their residues have been detected in blood, urine, breast milk even weeks after the last use. They act as hormone disruptors, can cause allergies, and even contribute to cancer, especially with long-term use. They are already banned in some countries.

4. Comfortable texture. Choose a product that is non-sticky, non-greasy, absorbs quickly, and blends well with makeup. This is the formula that will become part of your daily routine, not an exception for the beach. And

5. Care components in the composition. A high-quality SPF can moisturize, strengthen the skin barrier and act as an antioxidant. These can be peptides, vitamin E, plant extracts or niacinamide. A product that can work as a 3-in-1 – protect from the sun, moisturize and lighten the skin from pigmentation can be considered very successful.

6. Consider your lifestyle. If you are often outdoors, actively moving, or near water, choose a product that you will be prepared to reapply every 2 hours.

Sunscreen is a habit that saves not only from burns, but also from pigmentation, early wrinkles and even skin cancer. The right amount, a reliable formula, regularity and attention to detail – this is what, as Natalia Bobok explains, makes SPF protection truly effective, safe and convenient for regular use.