Sunscreen: Why One Application Is Not Enough When Spending Time at the Beach, the Pool, or in Direct Sun

We are used to applying sunscreen in the morning, before we leave the house, and feeling we have done our part.

But what happens when we spend several hours by the pool, sit on the beach, swim, or simply are outside with the face exposed to the sun?

Does one application of SPF 50 really protect us throughout the whole day?

The answer is no.

And this is one of the most important things worth understanding about sun protection.

A high protection factor does not grant unlimited protection in time, and even SPF 50 requires reapplication during prolonged exposure.

What does the SPF number really mean?

SPF is short for Sun Protection Factor.

The number refers to the level of protection of the preparation against UVB radiation, which is one of the central factors for sunburns and also contributes to the risk of skin cancer.

Under standard test conditions, when a sufficient quantity is applied:

• SPF 15 filters about 93% of UVB radiation.
• SPF 30 filters about 97% of UVB radiation.
• SPF 50 filters about 98% of UVB radiation.

The difference in percentages may look small, but it is important to understand that no protection factor blocks 100% of solar radiation.

In addition, the actual protection depends on the quantity applied, the uniformity of application, and the degree to which the preparation remains on the skin.

SPF 50 does not mean one can stay in the sun 50 hours, or that it grants protection for a fixed period of time.

Not all solar radiation causes immediately visible damage

When we think of sun damage, the first thing coming to mind is red skin or a sunburn.

But there are two central types of ultraviolet radiation important to know.

UVB radiation

Connected especially to sunburns, damage to the DNA of skin cells, and the development of skin cancer.

UVA radiation

Penetrates deeper into the skin and contributes to processes of premature aging, collagen damage, the appearance of wrinkles, pigmentation spots, and also the risk of skin cancer.

The meaning is that even if we sit in the sun and do not burn, damage to the skin can still occur.

Therefore it is important to choose a sunscreen marked Broad Spectrum — broad-range protection against UVA and UVB.

What happens when we sit by the pool?

Imagine a pleasant day by the pool.

We apply sunscreen before leaving the house, settle onto a lounge chair, read a book, enter the water occasionally, and return to tan or rest.

During this time the skin is exposed to radiation, even when we do not feel especially strong heat.

In addition, water and light surfaces can reflect part of the solar radiation and contribute to overall exposure.

But the main problem is not only the reflection.

It is the length of time we are outside, especially during the hours when UV radiation is strong.

The more prolonged the exposure, the greater the importance of correct application, renewing the protection, and using shading means.

Is SPF 50 enough for a whole day at the pool?

No.

Even if we used a quality SPF 50 sunscreen, the application should be renewed at least every two hours while staying outside.

If we enter the water, sweat, or towel off, it may be necessary to renew the application earlier.

The reason is simple.

The protective layer applied to the skin does not necessarily remain uniform over time.

Water, sweat, contact with the hands, toweling, and friction can reduce the quantity of preparation remaining on the skin.

Therefore one morning application does not suffice for prolonged sun exposure.

And what about water-resistant sunscreen?

Here it is important to understand the meaning of the term Water Resistant.

In the United States, a sunscreen defined as water resistant is tested for maintaining its protection level during 40 or 80 minutes of activity in water or sweating, according to the marking on the package.

But there is no such thing as a sunscreen that is completely Waterproof.

Even a water-resistant cream is not intended to remain on the skin without limit.

If you entered the pool, swam, or toweled off, the protection should be renewed according to the product instructions, especially after toweling.

It is also important to know that 80 minutes of water resistance do not mean one can stay 80 minutes in the sun without limit or without additional protective means.

How much sunscreen should be applied to the face?

One of the most common mistakes is using too small a quantity.

We apply a few dots on the forehead, cheeks, and nose, spread them, and assume the skin is protected.

But SPF tests are done with a standard quantity of 2 milligrams of preparation per square centimeter of skin.

In practice, many people apply much less.

When too small a quantity is applied, the protection level obtained may be significantly lower than the one stated on the package.

Therefore it is important to apply a generous, uniform layer covering all exposed areas.

Regarding the face and neck, the two-finger rule is sometimes used as a convenient estimate, but the exact quantity depends on the area size and the texture of the preparation.

There is no need to rely only on this rule. The main thing is to reach full, uniform coverage.

And do not forget the ears, hairline, neck, and décolletage.

These are areas we tend to miss.

Why do the face specifically need special attention?

Facial skin is one of the areas most exposed to the sun during life.

Even when we do not go to the beach, our face is exposed to UV radiation during walking, driving, sitting outside, and other daily activities.

The accumulated exposure over the years is one of the central factors for premature skin aging.

UV radiation can affect collagen and elastin fibers, contribute to the appearance of spots, and cause changes in skin texture and elasticity.

This process is called Photoaging — aging of the skin as a result of radiation exposure.

Unlike natural aging, which is an unavoidable part of life, a significant part of the damage caused by sun exposure can be reduced through correct protection.

Can one tan without causing damage to the skin?

I know that for many women tanned skin is associated with a healthy, fresh, summery look.

But biologically, a tan formed from UV radiation exposure is the skin's response to damage caused by the radiation.

The skin increases melanin production in an attempt to provide a certain protection against further exposure.

Therefore there is no such thing as a UV tan that is damage-free.

Even when we use sunscreen, a certain amount of radiation can still reach the skin.

This is one of the reasons sunscreen should not be used as permission to stay in the sun for hours just to tan.

The goal of sunscreen is to reduce the harmful exposure, not to allow us to extend it without limit.

Is there a difference between sitting in the shade and sitting in direct sun?

Definitely.

Shade can significantly reduce exposure to direct radiation, and therefore it is an important part of sun protection.

But even in the shade we may be exposed to UV radiation arriving from the sky or reflected from surrounding surfaces.

Therefore when we sit for hours by the pool or on the beach, it is worth combining several protective means.

A broad-spectrum sunscreen with SPF 30 at least, and preferably SPF 50 when prolonged exposure is expected, is only part of the routine.

A wide-brimmed hat, sunglasses with UV protection, suitable clothing, and sitting in the shade can add important protection.

Especially during the hours when the UV index is high.

Should exposure to the sun be avoided at certain hours?

The intensity of UV radiation changes during the day, according to the season, geographic location, and environmental conditions.

In sunny places, and especially in summer, the radiation can be very strong during the hours around noon.

Therefore it is worth checking the local UV index.

When the index is high, it is advisable to reduce prolonged direct exposure and prefer shade or activity during hours when the radiation is weaker.

It is important to remember that even on a cloudy day a considerable part of UV radiation can reach the skin.

Therefore clouds are not a substitute for sunscreen.

Is makeup with SPF enough for a day at the pool?

Many makeup products today contain a protection factor.

This can be an advantage in daily use.

But in most cases we apply foundation in a quantity much smaller than the quantity required to obtain the SPF level stated on the package.

Therefore, especially during prolonged sun exposure, it is better to use a dedicated sunscreen in a sufficient quantity and not rely on makeup alone.

The sunscreen can be applied as part of the morning routine and then makeup applied.

During the day it is important to renew the protection even if we are wearing makeup.

Can sunscreen prevent pigmentation spots?

Exposure to UV radiation can trigger melanin production and worsen certain pigmentation conditions.

For example, sun spots and melasma.

Consistent use of broad-spectrum sunscreen is a central part of prevention and treatment of these conditions.

In melasma cases, visible light too, especially at certain wavelengths, can contribute to worsening.

Therefore a tinted sunscreen containing iron oxides — Iron Oxides — is sometimes recommended, helping protect against part of the visible light.

But even an excellent sunscreen does not guarantee spots will not appear.

It is part of a protection and treatment array that should be adapted to the skin condition.

Should sunscreen be renewed even if we do not enter the water?

Yes.

When we are outside for hours, the accepted recommendation is to renew the application at least every two hours, even if we did not swim.

The protection may be harmed as a result of sweat, contact with the skin, friction, and loss of uniformity of the preparation layer.

If we sit indoors, away from windows and without significant sun exposure, the need for frequent renewal may be different.

But on a pool, beach, or prolonged outdoor sitting day, it is important to adhere to renewing the protection.

A correct protection routine for a beach or pool day

I love thinking of sun protection as a simple routine, not a one-time action.

Before leaving the house

Apply a broad-spectrum, water-resistant sunscreen, with SPF 30 at least, and in prolonged exposure I prefer SPF 50.

Cover the face, ears, neck, décolletage, and every other area exposed to the sun.

During the stay outside

Try to sit in the shade as much as possible, especially during the hours when radiation is strong.

Use a wide-brimmed hat and suitable sunglasses.

At least every two hours

Renew the sunscreen in a sufficient quantity.

After swimming or toweling

Renew the application according to the product's water resistance instructions. After toweling, reapply, even if two hours have not yet passed.

At the end of the day

Clean the skin gently and use a moisturizer suited to the skin type.

If the skin was sunburned, it is important to avoid further exposure and not use irritating products on the damaged area.

And what about vitamin D?

Sometimes I am asked whether regular sunscreen use might cause vitamin D deficiency.

Vitamin D can be created in the skin following UVB radiation exposure.

But there is no medical recommendation to expose oneself to the sun unprotected in order to raise vitamin levels.

Vitamin D can be obtained from food, enriched products, and if needed from supplements, according to medical recommendation.

The cumulative risk of unprotected UV radiation exposure does not justify using tanning as a means of obtaining vitamin D.

Our approach at OrOrgani

At OrOrgani we believe a good care routine begins first of all with protecting the skin.

We can invest in serums, creams, and active ingredients, but if the skin is exposed again and again to solar radiation without sufficient protection, we may harm some of the results we are trying to achieve.

Therefore I see sunscreen as one of the most important products in the care routine.

Especially when we live in a sunny area or love spending time by the sea and pool.

A high protection factor, like SPF 50, can provide significant protection when used correctly.

But it does not replace reapplication, shade, and additional protective means.

Our goal is not to avoid all outdoor activity.

I love sun, sea, pool, and open air.

The goal is to enjoy all of these in a way that reduces as much as possible the cumulative damage to the skin.

In summary: Sunscreen is not one morning application

If there is one thing I want you to remember from this article, it is that sunscreen is not a product applied once and forgotten.

In prolonged sun exposure, especially at the beach or pool, it is important to renew the protection at least every two hours and after swimming, significant sweating, or toweling, according to the product instructions.

Even SPF 50 does not grant immunity against solar radiation.

Using a sufficient quantity, choosing a broad-spectrum preparation, reapplication, and combining shade, hat, and suitable clothing are the correct way to protect the skin.

I believe one of the most important things we can do for our skin is not only to treat damage already created, but to prevent as much as possible the damage of tomorrow.

We do not need to give up the sun to maintain healthy skin.

We only need to learn to enjoy it wisely.

With love,
Nurit
OrOrgani

With love,
Nurit Rozenblat
OrOrgani

FOLLOW ORORGANI    Website · Blog · YouTube · Instagram · Facebook · Threads · Medium · Substack