Sunscreen Vs. Sunblock: Which One Should I Use?

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Sunscreen Vs Sunblock

While it’s not uncommon to hear the words sunblock and sunscreen used interchangeably, they actually represent two completely different types of sun protection.

Sunscreen

Sunscreen acts as a chemical defense by penetrating the skin and absorbing UV rays before they can harm the dermal layers.

Many sunscreen contain ingredients like avobenzone, oxybenzone, and para-aminobenzoic acid (PABA) designed to absorb the sun’s rays.

Sunblock

On the other hand, sunblock offers physical protection against ultraviolet (UV) rays. It forms a protective layer on the skin’s surface and acts as a protector. Most common ingredients include zinc oxide or titanium oxide. Sunblocks are often opaque and easily noticeable when applied.

Some products on the market combine sunscreen and sunblock in their formulation.

Should I use sunscreen or sunblock?

According to the Skin Cancer Foundation choosing between sunscreen and sunblock depends on factors like your skin type. For individuals with sensitive skin, sunblocks with zinc oxide and titanium dioxide are better tolerated, and these ingredients are commonly found in products for children who have different sun protection needs.

If you have specific skin conditions, such as rosacea or allergy-prone skin, it’s best to avoid products with fragrances, preservatives, oxybenzone, or PABA, which are often present in sunscreens.

The Environmental Working Group has issued a warning about the usage of sun protectants containing oxybenzone due to its potential to trigger allergic reactions.

Before trying a new sunscreen or sunblock, read the product label carefully to ensure you receive the appropriate protection and to avoid ingredients that might trigger sensitivities.

When considering sun protection, experts recommend products with:

• SPF 30 or higher
• Broad spectrum protection
• Water resistance

What is SPF?

SPF, which stands for sun protection factor, indicates how effectively a product shields you from the sun’s ultraviolet B (UVB) rays.

The SPF number indicates the time it takes for the skin to turn red when exposed to the sun with the protection of the product compared to the time it would take without any protection.

For instance, SPF 30 means it will take 30 times longer for your skin to redden compared to being exposed without protection. A product with SPF 50 will take 50 times longer etc.

As per the Skin Cancer Foundation, a product with SPF 30 permits approximately 3 percent of UVB rays to reach your skin, while a product with SPF 50 allows about 2 percent.

Other important label information found on sun protectant products:

Water resistant

The FDA no longer allows manufacturers to claim their products as “waterproof.” Instead, look for water-resistant products that remain effective for 40 minutes in the water before requiring reapplication. Products labeled as “very water resistant” typically last for 80 minutes in the water.

Broad spectrum

The term “broad spectrum” indicates that the product can protect against both UVA and UVB rays.

Sports

The term “sports” is commonly used to suggest water and sweat resistance, even though it has not been officially approved by the FDA for sun protection.

Sensitive skin

Although the FDA hasn’t officially approved the term “sensitive skin” for sun protection, it likely implies that the product is hypoallergenic and free from PABA, oils, or fragrances. Always check the label to see if any of these ingredients may irritate your skin before use.

Three reasons to use sun protection

Three compelling reasons to use sun protection include:

• UV radiation from the sun poses a significant threat for skin cancer
• Sunburn damages skin cells and blood vessels due to UV radiation, leading to weakened and easily bruised skin
• A 2013 study of Caucasian women has shown that UV exposure is responsible for around 80 percent of visible facial aging signs, including wrinkles, reduced elasticity, pigmentation, and texture degradation

Ultraviolet radiation (UV)

Sunlight includes visible light, heat, and UV radiation. UV radiation is categorized into three types based on its wavelength.

UVA

UVA, which constitutes about 95 percent of the UV radiation reaching the Earth’s surface, has a relatively long wavelength and can penetrate deep into the skin. It’s responsible for immediate tanning, skin wrinkling, aging, and the development of skin cancers.

UVB

UVB has a medium wavelength and is partially blocked by the atmosphere, making it unable to penetrate deeper than the superficial skin layers. UVB is responsible for delayed sun tanning and burning, and it can accelerate skin aging and promote skin cancer development.

UVC

UVC has a short wavelength and is entirely blocked by the Earth’s atmosphere, so it’s not a concern with sun exposure. However, it can be dangerous when exposed to an artificial radiation source.

How do i protect myself from the harmful effects of the sun?

To protect yourself from the harmful effects of the sun, staying out of the sun during peak hours (10 a.m. to 3 p.m.) is the best approach, although it may be challenging.

Additional protective measures include:

• Wearing UV-filtering sunglasses
• Wearing protective clothing like long pants, long-sleeved shirts, and wide-brimmed hats

Conclusion

It’s common for numerous sun protectants to combine sunscreen and sunblock. Therefore, it’s essential to carefully read the product label before buying and using it.

When selecting sun protectants, opt for products with an SPF of 30 or higher, offering broad spectrum protection and water resistance. To avoid skin irritation, steer clear of products containing ingredients that may be sensitive to your skin.

To prevent sunburn, remember to reapply sun protectants every two hours, or more frequently, every 40 to 80 minutes, especially after swimming or sweating.

Here is a table that summarizes the key differences between sunscreen and sunblock: