The right SPF can make a real difference to how well your skin is protected in the sun. But SPF numbers alone don’t always tell the full story.
In this guide, we explain what SPF really means, why broad-spectrum protection matters and how organic sunscreens can offer reliable protection with a gentler feel on skin.
At a glance:
- SPF measures protection against UVB rays, which cause sunburn, but doesn’t indicate UVA protection
- SPF15, 30 and 50 provide increasing UVB protection (93%, 97%, 98%)
- Effective protection depends on proper and regular application
- Broad-spectrum sunscreens protect against both UVA and UVB rays
- We offer organic, broad-spectrum sun creams that are kind to sensitive skin
- Best natural sun cream: Green People Scent Free Sun Cream SPF30
What does SPF actually mean?
To understand SPF, it’s helpful to first look at the different types of UV radiation from the sun and how they affect the skin.
The sun produces two main types of ultraviolet (UV) rays that impact skin health in different ways: UVA and UVB.
UVA rays penetrate deep into the skin and are largely responsible for premature ageing, including fine lines, wrinkles and long-term skin damage. They are present throughout the year, even on cloudy days, and play a role in the development of skin cancer.
UVB rays mainly affect the outer layers of the skin and are the primary cause of sunburn. They also contribute to skin cancer risk, but their intensity varies depending on the season, time of day and geographic location.
SPF, which stands for Sun Protection Factor, measures how effectively a sunscreen helps protect the skin from UVB rays. For example, an SPF30 sunscreen means it would take approximately 30 times longer for skin to begin burning than if no sunscreen were applied.
SPF does not measure protection against UVA rays, which is why it’s important to choose a broad-spectrum sunscreen. Broad-spectrum formulas are designed to help protect the skin from both UVA and UVB rays, supporting overall skin health and long-term protection.
Do natural and organic sunscreens contain effective SPF?
Yes. All sunscreens sold in the UK and EU, whether natural, organic or conventional, must meet strict scientific and legal standards before they can be marketed as providing sun protection.
Sunscreens are regulated under the UK and EU Cosmetics Regulation (EC) No. 1223/2009 and must be tested in line with recognised international methods, such as ISO 24444 for SPF (UVB protection) and ISO 24443 for UVA protection. In addition, sunscreen claims must comply with the EU Recommendation 2006/647/EC, which sets clear rules on SPF labelling and broad-spectrum protection.
This means that natural and organic sunscreens are required to meet exactly the same protection standards as any other sunscreen, so when applied correctly, they provide effective and reliable SPF.
The key difference between organic sun care and many high street sunscreens lies in the formulation. Organic sunscreens are typically designed to be gentler on the skin, using carefully selected ingredients and avoiding harsh or pore-clogging substances, making them particularly suitable for sensitive or delicate skin.
How is the SPF calculated?
SPF (Sun Protection Factor) is measured under controlled laboratory conditions and is based on a concept called the Minimal Erythema Dose (MED) – the smallest amount of UVB radiation needed to cause visible redness on the skin.
In testing, SPF compares how much UVB exposure is needed to cause redness on protected skin versus unprotected skin. For example, an SPF15 sunscreen means the skin can tolerate around 15 times more UVB radiation before showing redness than it would without protection. SPF30 allows for around 30 times more UVB exposure under the same test conditions.
SPF is sometimes explained using time as a simple guide – for instance, if unprotected skin begins to redden after 10 minutes, an SPF30 sunscreen could, in theory, allow for longer exposure before redness occurs. However, this is only an illustration. In real life, SPF does not translate into a fixed amount of safe time in the sun.
Actual protection varies depending on skin type, the intensity of sunlight, time of day, location, sweating, swimming and – most importantly – how generously and evenly the sunscreen is applied.
To achieve the level of protection shown on the label, sunscreen needs to be applied in sufficient quantity and reapplied regularly, especially after swimming, sweating or towel drying. Am I applying enough sunscreen?
Do I get twice the protection by using SPF30 vs SPF15?
NO - An SPF15 sun lotion, when applied properly, protects you against 93% of UVB. An SPF30 protects you against 97% of UVB.
What is the difference between SPF15, 30 and 50?
The main difference between SPF15, SPF30 and SPF50 is the level of protection they provide against UVB rays, which are responsible for sunburn.
- SPF15 blocks around 93% of UVB rays and is considered low to medium protection
- SPF30 blocks around 97% of UVB rays and is considered medium to high protection
- SPF50 blocks around 98% of UVB rays and is considered high protection
- SPF50+ blocks slightly more than 98% of UVB rays and is classed as very high protection
No sunscreen blocks 100% of UVB rays. While higher SPF products do offer increased protection, the difference between SPF30 and SPF50 is relatively small. Using enough sunscreen, applying it evenly and reapplying regularly are just as important as choosing a higher SPF.
We offer sunscreens in SPF15, SPF30 and SPF50, so you can choose the level of protection that best suits your skin and lifestyle.
Does SPF50 last longer than SPF30?
In laboratory testing, a higher SPF allows the skin to tolerate more UVB exposure. However, in everyday use, SPF50 does not last longer than SPF30.
Both SPF30 and SPF50 sunscreens should be reapplied every 2–3 hours, and more frequently if you are swimming, sweating or towel drying, to maintain effective protection.
What SPF level should I choose?
Green People’s natura and organic sun creams offer broad-spectrum UVA and UVB protection, using carefully selected modern UV filters that are designed to be gentle on the skin and more considerate of the natural environment.
We offer a range of SPFs from 15 to 50, allowing you to choose the level of protection that best suits your skin, your activities and the conditions you’re exposed to without using more protection than you need.
By offering a range of SPFs, Green People prioritise comfort, skin sensitivity and real-world wearability. Our philosophy recognises that UV exposure changes with season, climate, skin type and lifestyle, and your SPF should adapt with it.
Charlotte Vøhtz, Founder, Green People
The importance of broad-spectrum protection & applying sunscreen properly
SPF refers specifically to protection against UVB radiation, which is responsible for sunburn. On its own, an SPF number does not indicate the level of protection a product offers against UVA rays, which penetrate deeper into the skin and contribute to long-term skin damage.
This means that skin may not show immediate signs of burning or redness, yet UV exposure can still be occurring, particularly if sunscreen is not applied generously or reapplied regularly. Over time, this can contribute to premature skin ageing and increased skin cancer risk.
Understanding SPF numbers is only part of the picture. How sunscreen is applied is just as important as the SPF chosen. To achieve the level of protection stated on the label, sunscreen needs to be applied liberally and reapplied regularly throughout the day, regardless of the SPF used.
Charlotte Vøhtz says:
Too many people are suffering needlessly from skin cancer. We know that applying SPF daily is key to preventing this but the truth is, many are underapplying their sunscreen and relying on a false sense of protection from insufficient SPF.
It's a misconception that if you haven’t burned, no damage has been done. The reality is that it is essential to shield your skin from both UVA and UVB rays. This can only be achieved by applying broad-spectrum SPF regularly and liberally throughout the day. Remember, if you don't apply enough, you won't even come close to the advertised level of protection.
Sunscreen is tested at a specific application level, and using less than this significantly reduces the level of protection. Research shows that applying around half the recommended amount can reduce the effective SPF to as little as the square root of the labelled value.
In practical terms, this means that an SPF25 sunscreen, when underapplied, may offer protection closer to SPF5 rather than the level shown on the label. This is why applying sunscreen generously and evenly is essential to achieving effective protection."
Discover our natural sun creams
If you are looking for a sun cream for sensitive skin, prickly heat or simply to look after your skin, a Green People sun cream might be the perfect choice for you.
What makes us different?
- Natural & organic
- Free from drying alcohol
- Gentle on sensitive skin & prickly heat
- Ocean-friendly
- Non-greasy
- Water-repellent
The best-seller
Not sure where to start? Our Scent Free Sun Cream SPF30 is a customer favourite.
Fragrance-free and suitable for sensitive skin, it provides reliable broad-spectrum UVA and UVB protection with a lightweight, non-greasy feel.
Scent Free Sun Cream SPF30 200ml
Protect sensitive skin naturally with our best-selling SPF30 sun cream£33.50
For kids
Our Organic Children Scent Free Sun Cream SPF30 is specially formulated for delicate skin and packed with soothing Aloe Vera.
Gentle, fragrance-free and water-repellent, it’s suitable for children and babies aged 6 months+.
Organic Children Scent Free Sun Cream - SPF30 150ml
Discover peace-of-mind protection with our best-selling kids’ SPF30 sun cream£30.00
For the face
Our Scent Free Facial Sun Cream SPF30 is specially formulated for dry and sensitive skin.
So much more than just sun cream, this 2-in-1 day cream with SPF30 moisturises, balances and protects with organic Aloe Vera, Cocoa Butter, Inulin Prebiotics and Edelweiss.
Scent Free Facial Sun Cream - SPF30 50ml
Shield and hydrate with this facial SPF. Ideal for dry or sensitive skin.£30.00
SPF, or Sun Protection Factor, indicates how well a sunscreen protects your skin from UVB rays, which cause sunburn. For example, SPF30 means it would take roughly 30 times longer for your skin to burn than without protection. It doesn’t measure UVA protection, so a broad-spectrum product is still essential.
Broad-spectrum sunscreens protect against both UVA and UVB rays, offering all-round protection. This means your skin is shielded not just from burning, but also from deeper damage that leads to premature ageing and long-term skin issues.
Organic sunscreens use gentler, non-toxic UV filters, often mineral-based, which are kinder to sensitive skin and less likely to irritate. Many high street sunscreens contain harsher chemical filters and other ingredients that can cause reactions or be less environmentally friendly.
Yes, up to 80% of UV rays can penetrate clouds, and UVA rays are present year-round. Applying sunscreen daily helps protect against long-term skin damage even when it doesn’t feel sunny.
Our friendly UK customer care team is happy to help you with any questions you may have about UV protection and our organic sun creams. Please call us on 01403 740350 or contact us on social @GreenPeopleUK.
BY CHARLOTTE, FOUNDER OF GREEN PEOPLE
This blog post has been written by Charlotte Vøhtz, founder of Green People, who has 25+ years of experience in the natural and organic beauty industry.
A recognised leader in the field of organic beauty, Charlotte helped inform the UK's first organic beauty standards and was voted the People’s Choice in the 2023 list of Who’s Who in Natural Beauty.
A published author, she wrote the organic beauty bible ‘Naturally Gorgeous’. Previously, she qualified as a nurse and spent over 10 years working in pharmaceuticals.
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