Why sunscreen matters: what you need to know about sun protection

Read Time: 6 minutes

Last updated: 07/07/2026

Woman applying Altruist Sunscreen Outdoors

Summer is here, which means spending more time outdoors than ever. With UV levels at their highest, protecting your skin becomes especially important during this season.

Choosing the right sunscreen plays a major role in preventing sunburn, and long-term UV damage. However, with so many SPF levels and formulations available, it can be difficult to know what to look for.

So how do you choose the right sunscreen, and what really matters when it comes to keeping your skin safe?

Why sunscreen is important all year round

Many people associate sunscreen with summer holidays and sunny days at the beach, but UV exposure is something we encounter every day. Whether you're commuting or exercising outdoors, your skin is always exposed to ultraviolet (UV) radiation throughout the year.

Over time, this exposure builds up and can have a lasting impact on skin health. That's why protecting your skin should be a daily priority, regardless of the season.

Some of the most important reasons to apply sunscreen are:

Preventing sunburn: Sunburn is a visible sign of skin damage caused by excessive UV exposure. Repeated sunburn can increase the risk of long-term skin damage and skin cancer.

Reducing the risk of skin cancer: Prolonged exposure to UV radiation is one of the leading risk factors for melanoma and other forms of skin cancer. Consistent sun protection can help significantly reduce this risk.

Preventing premature skin ageing: UV exposure accelerates the skin's ageing process, contributing to wrinkles, fine lines, dark spots, and loss of elasticity.

Supporting overall skin health: Protecting your skin from UV rays helps prevent dryness, irritation, and cumulative damage, keeping your skin healthier in the long run (Masonic Cancer Center, 2025; Skin Cancer Foundation, 2026).

UVA and UVB what is the difference?

You've probably seen it on sunscreen labels before: "protects against UVB" or "protects against UVA." But what do these terms mean, and why are both so important when it comes to protecting your skin?

Ultraviolet radiation (UV) consists of different types of rays that affect the skin in separate ways. There are two types of UV-rays, and understanding the difference can help you make a more informed choice about choosing sunscreen.

UVA

UVA rays penetrate deep into the skin and are present all year round, even on cloudy days and through glass. They are mainly responsible for premature skin ageing, such as wrinkles, fine lines, and pigmentation. Because they reach deeper skin layers, their damage builds up over time.

You can remember this easily by the letter "A" in UVA, which stands for ageing.

UVB

UVB rays affect the outer layer of the skin. They are the primary cause of sunburn and are the strongest during the warmer months when the UV index is high. UVB rays also directly damage skin cell DNA, which can lead to skin cancer. A simple way to remember this, is that the "B" in UVB stands for burning.

(Skin Cancer Foundation, 2026).

How to choose the best sunscreen?

Woman holding Altruist sunscreen up to the camera

With so many sunscreens available, choosing the right one can feel overwhelming. While different formulations and textures may suit different preferences, there are a few key factors to consider when selecting sunscreen that provides effective protection:

  • Choose a broad-spectrum sunscreen: A sunscreen should protect against both UVA and UVB rays. A broad-spectrum sunscreen helps protect against both types of UV radiation.
  • Choose SPF 30 or higher: SPF (Sun Protection Factor) measures protection against UVB rays. Dermatologists generally recommend using sunscreen with at least SPF30 for everyday use. SPF 30 filters around 97% of UVB rays, while SPF 50 filters around 98%. Although no sunscreen can block 100% of UV radiation, higher SPF products can provide additional protection, particularly for those with fair skin, a history of skin cancer, or prolonged sun exposure.
  • Look for the term 'water-resistant': If you play water sports, swim, or tend to sweat a lot, a water-resistant sunscreen is what you should look for. This means the product retains around 50% of its effectiveness after 40 minutes of water exposure. However, it is important to note that even water-resistant sunscreens should be reapplied after swimming, sweating, or towel drying to maintain optimal protection.
  • Choose a formula suitable for sensitive skin: Many dermatologists recommend fragrance-free sunscreens, particularly for people with sensitive skin. Fragrance is a common trigger for irritation and allergic reactions, making fragrance-free formulations a safer choice for daily use (BAD, 2025).

Why choose Altruist sunscreen

Altruist Sunscreen Selection and Certifications and Dr Birnie

Altruist is a sunscreen and skincare brand founded in 2015 by British skin cancer surgeon and dermatologist Dr Birnie.

His mission is to help reduce the incidence of skin cancer by providing accessible and affordable sunscreen, while also increasing awareness and better education about sun protection.

In addition, Altruist donates 10 pence from every product sold to charities that support people with albinism in Africa. They face a significantly higher risk of skin cancer and often have limited access to adequate sun protection and healthcare.

What sets Altruist sunscreen apart?

All Altruist sunscreens provide:

  • Broad-spectrum protection: The Altruist sunscreen range provides broad-spectrum protection, including a 5-star UVA ultra protection that exceeds minimum EU requirements.
  • Fragrance and paraben free formulations: The products are formulated without fragrance or parabens, which makes them suitable for people with sensitive skin.
  • Water-resistant formulas: All sunscreens are water resistant and retain part of their protection during swimming or sweating (around 50% after short exposure). Reapplication is still recommended after swimming/water exposure, which makes them more reliable than non–water-resistant sunscreens.
  • Non-comedogenic and hypoallergenic formulas: Designed not to clog pores, making them suitable for oily and acne-prone skin types and reducing the risk of breakouts. The formulas are also developed to minimize the risk of allergic reactions, and therefore suitable for all skin types.

SPF and UPF clothing: combined sun protection

Most people are aware that sun protection is essential, and sunscreen plays an important role in that. In addition to sunscreen, we also know that covering up with clothing is one of the most effective ways to protect yourself from UV exposure. The only issue is that not all clothing offers reliable UV protection.

That's where UPF clothing makes the difference. Unlike a normal t-shirt, which can let through as much UV as wearing only SPF 5 sunscreen, a certified UPF 50+ garment blocks around 98% of UV rays and keeps doing so even when wet, making it a far more effective layer of protection.

equatorsun was built around exactly this. Every piece is designed for everyday wear and certified UPF 50+, so reliable sun protection becomes something you can simply put on and forget, comfortable, practical, and one less thing for a busy family to think about.

In the end, SPF and UPF simply work best together: SPF protects the skin that is exposed, while UPF clothing covers and protects larger body parts throughout the day. It's not about choosing one or another, it's the combination that makes sun protection truly effective according to several global dermatology and skin cancer organizations (American Academy of Dermatology, Skin cancer foundation, British Association of Dermatology).

Frequently asked questions

When should I use sunscreen?

You should use sunscreen whenever you are outdoors in daylight for more than around 15 minutes. Keep in mind that UVA rays can also penetrate glass, meaning you are still exposed while sitting in a car or near windows.

How often should I reapply sunscreen?

Sunscreen should be reapplied every 2 hours to maintain effective protection. If you've been swimming, sweating, or toweling off, it's important to reapply straight away, as this can reduce the effectiveness of the protection.

Does Altruist test its products on animals?

No, we do not. It's against EU law for any cosmetic to be tested on animals and we definitely do not test on animals.

Does Altruist use chemical or physical filters?

Altruist uses both physical and chemical filters to achieve optimum protection. The chemicals in Altruist Sunscreen ensure it works well and feels great on the skin and have been very thoroughly assessed by SCCS (the European cosmetics safety organisation).

Consulted sources

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