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Complete Guide to Sunscreen: SPF, UVA/UVB, Regulations, and Innovations
- Daniel Jiménez
- May 8
- 20 min read
Updated: May 9
The Sun Protection Factor (SPF) measures a cosmetic product's ability to protect the skin from UVB ultraviolet radiation, which causes sunburn and, in the long run, cellular damage. Beyond its technical effectiveness, all sunscreens must comply with a rigorous regulatory framework that guarantees their safety, stability, and truthful labeling.
In the European Union, the marketing of sunscreens is governed by Regulation (EC) No. 1223/2009 on cosmetic products and by the European Commission's guidelines for the "in vivo reference method" for determining SPF. In the United States, the FDA classifies sunscreens as "over-the-counter" and requires specific clinical studies for each SPF level, as well as clear water-resistance statements.
This guide will address, in a streamlined and practical way, both the fundamentals of SPF (mechanisms of action, filter types, and evaluation criteria) and the main legal and labeling requirements in the most relevant markets, so you can design, develop, or select safe formulas that comply with current regulations.
Table of contents
What is SPF (Sun Protection Factor) and how is it measured?
The Sun Protection Factor (SPF) is an index that indicates the effectiveness of a sunscreen in protecting the skin against UVB radiation (the main cause of sunburn).
By definition, SPF is determined in the laboratory by comparing the amount of UV radiation required to produce minimal redness ( minimal erythemal dose , MED) on sunscreen-protected skin with that on unprotected skin.
In simple terms, an SPF of 30 means that it would take ~30 times longer for the skin to redden with the product applied than without it, under the same conditions. To obtain this measurement, a standard amount of 2 mg/cm² of product is applied to the skin of volunteers and exposed to controlled UV light until mild redness occurs.
It's important to understand that SPF primarily refers to UVB protection; UVA protection isn't reflected by the SPF number. A higher SPF indicates greater UVB blockage, but the difference in protection isn't linear.
For example, SPF 15 blocks about 93% of UVB rays, SPF 30 about 96-97% , SPF 50 about 98% , and SPF 100 about 99% . In practice, this means that going from SPF 30 to SPF 50 only reduces the UVB radiation reaching the skin by a few percentage points (letting through ~3% vs ~2%), although that apparent 1% difference means that 50% more UVB radiation reaches the skin with SPF 30 than with SPF 50.
The following graph illustrates the proportion of UVB blocked by different SPF levels:
There's no direct relationship between SPF and duration of protection: a higher SPF doesn't mean you can stay in the sun longer without reapplying. All sunscreens degrade with exposure to the sun, water, or sweat, so it's recommended to reapply every two hours at most, regardless of the SPF.
Additionally, the SPF number assumes a generous application of the product; in real life, many people apply less, achieving less effective protection than the stated SPF. Therefore, using at least SPF 30 (high) or 50 (very high) daily and reapplying frequently is key to adequate protection.
Differences between UVA and UVB protection, and why both are important
Diagram of the penetration of different wavelengths of light into the skin. The purple portion (approximately <320 nm) corresponds to UVB, which remains mostly in the epidermis, while the pink portion (320-400 nm, UVA) penetrates deeper into the dermis.
Ultraviolet light from the sun is composed primarily of UVA and UVB rays . Although both are invisible to us, they have key differences:
Wavelength range
UVB covers approximately 280 to 320 nm, while UVA ranges from ~320 to 400 nm. Within UVA, a distinction is sometimes made between short UVA (320-340 nm) and long UVA (340-400 nm).
Proportion in sunlight
About 95% of the UV radiation reaching the Earth's surface is UVA, and about 5% is UVB. This is because the ozone layer filters out most of the most energetic UVB radiation, while UVA radiation passes through the atmosphere almost unimpeded.
Skin penetration
UVB rays have shorter wavelengths and penetrate only the superficial layers of the skin (epidermis). They are very energetic but do not reach the deep dermis. In contrast, UVA rays (longer wavelengths) penetrate deeper into the dermis, where they damage collagen and elastin fibers.
Biological effects
UVB rays are primarily responsible for sunburn or acute skin redness. They also induce delayed tanning by stimulating melanin production and can directly damage the DNA of skin cells, significantly contributing to the development of skin cancer .
UVA rays, on the other hand, cause an immediate tan (oxidation of existing melanin), but this is more deceptive , as the damage is not immediately visible. UVA rays generate free radicals in the skin that cause photoaging (wrinkles, dark spots, and loss of elasticity) and also contribute to the long-term risk of skin cancer .
For a long time, it was believed that UVA rays did not cause serious damage, but today we know that they can indirectly cause DNA damage and increase the likelihood of cancer.
Variation and scope
UVB intensity varies depending on the time of day and season; it is highest at midday and in summer, and virtually nonexistent at dawn/dusk or in winter at high latitudes. UVA rays, on the other hand, are present year-round and throughout the day with a relatively constant intensity.
In addition, UVA rays pass through clouds and glass: even on cloudy days or under indirect shade, UVA radiation reaches the skin, and glass in windows or cars blocks most UVB rays but lets most UVA rays pass through.
In short, both types of UV rays are harmful , and it's essential to protect yourself from both. A good sunscreen should be "broad spectrum," meaning it can filter out both UVB and UVA rays.
If we only protect ourselves against UVB (reflected by the SPF), we could avoid sunburn but still receive significant doses of UVA that accelerate skin aging and contribute to skin cancer , so when choosing a sunscreen, we should look for indications of UVA protection in addition to the SPF.
Comparison between UVA and UVB radiation
UVB (B = “Burning”) | UVA (A = “Aging”) | |
Approximate wavelength | 280 – 320 nm (UVB) | 320 – 400 nm (UVA; UVA-II 320-340, UVA-I 340-400) |
Percentage of UV that reaches the ground | ||
Skin penetration | ||
Main effects | ||
Diurnal/seasonal variation | ||
Ability to pass through glass | Very low (glass blocks almost all UVB) | High (passes through windows and clouds easily) |
Current regulations on photoprotection (EU requirements 2024 and beyond)
In the European Union , sunscreens are regulated as cosmetic products and must comply with current safety and labeling regulations. Although there is no specific European law for SPF, there are recommendations and technical standards widely adopted by the industry.
Highlights of the current regulations (updated to 2024) include:
Minimal UVA efficacy
The European Commission recommends (and in practice requires for labeling as "UVA") that UVA protection have a minimum value of at least 1/3 of the declared SPF . In other words, if a product is SPF 30, it should provide a UVA protection factor (UVA protection factor, measured by specific methods) of at least 10.
This requirement ensures proportional protection against UVA rays, which have historically been neglected in some products.
In addition, the sunscreen must reach a critical wavelength of 370 nm, ensuring coverage in the long UVA spectrum. Products that meet these criteria can display the UVA symbol (the letters "UVA" in a circle) on the packaging, indicating to the consumer that it offers broad-spectrum protection in accordance with European standards.
SPF labeling and categories
In Europe, SPF is typically labeled with standardized numbers and in protection categories. Claims of SPF above 50+ (50 plus) are not permitted on the label, even if the actual measured SPF exceeds 60. Categories are typically divided into low (SPF < 15), medium (15-25), high (30-50), and very high (50+).
For example, an SPF 30 product would be considered "high protection," and an SPF 50+ product would be considered "very high." It is also regulated that misleading terms such as "total protection" or "total screen" are not used, as no product blocks 100% of UV radiation.
List of permitted UV filters
EU cosmetic regulations ( Regulation EC 1223/2009 , Annex VI) maintain a list of authorized UV filter ingredients, with their maximum concentrations. Formulators may only use sunscreens that have been evaluated and approved by the European regulatory authority.
For example, commonly approved filters include avobenzone, octocrylene, Homosalate, and others, each with its own limits. This list is periodically updated; recently (until 2024), new filters have been introduced and others have undergone safety reviews.
Efficacy and testing requirements
To support the declared SPF, manufacturers must perform standardized testing (e.g., ISO 24444:2019 for in vivo SPF). Likewise, to claim UVA protection and use the UVA logo, they must perform UVA-PF testing (either in vivo using the PPD method or equivalent in vitro tests, e.g., ISO 24443 ).
If claims such as “water resistant” are made, a water resistance test must be carried out (e.g., 40 or 80 minutes of immersion according to COLIPA protocols) and the product must indicate how to use it correctly to maintain that protection.
Since 2022-2024, the EU has reinforced the importance of these tests: a product that does not meet the 1/3 UVA/SPF criterion or has not been adequately tested could be considered mislabeled or even unsafe by consumer authorities.
Other labeling provisions
The packaging must include usage recommendations (e.g., “reapply frequently, especially after swimming or sweating”), the expiry date (period after opening) indicating the product’s shelf life, and the list of ingredients with special indication of the presence of nanoparticles (e.g., “ Titanium Dioxide (nano) ” if titanium dioxide is used in nano form, as required by the EU). These measures aim to inform consumers and ensure correct use and transparency of the product.
In other regions, there are differences: for example, in the US, sunscreens are considered over-the-counter (OTC) products , and the FDA regulates permitted filters and "Broad Spectrum" labeling differently, requiring a certain UVA absorption ratio but without a numerical UVA-PF index as such. However, globally, the regulatory trend is similar: ensuring both UVA and UVB protection, robust efficacy testing, and clear communication so the user understands how to use the product.
In 2024, Europe maintains one of the strictest standards in terms of spectrum width and diversity of permitted filters, encouraging continued innovation in this field.
Improvements in photostability and synergies
Another line of innovation has been improving the photostability of organic (chemical) filters. A landmark example was the stabilization of avobenzone (a UVA-1 filter) by combining it with other photostable filters to prevent rapid degradation.
Today, high-quality formulations often combine multiple filters that complement each other: for example, a single product may contain a powerful UVA filter , a broad-spectrum filter and UVB filters such as octocrylene, homosalate, etc., achieving a reinforced broadspectrum effect.
Additionally, technologies such as filter encapsulation (entrapping the filter in a microscopic matrix) are used to reduce skin absorption and improve stability, or combinations of organic filters with mineral filters (titanium dioxide, zinc oxide) to obtain the benefits of both.
New filters and approvals
New filters have appeared on the European market in recent years.
Each innovation typically requires extensive safety studies before regulatory approval, but once approved, they offer formulators more tools to create lighter, clearer, and more effective sunscreens.
It's worth mentioning that in markets like the US, the approval of new filters has been slower (filters that are common in Europe have not been approved for years), but recently there's been a global trend toward harmonizing the availability of these ingredients given the recognition of their importance.
Textures and functional cosmetics
Innovation is not only emerging in the active ingredients, but also in the product form. Sunscreens have emerged with very light, cosmetically pleasing textures (e.g., water-based gels, transparent mists, solid sticks) to improve adherence for the consumer.
Antioxidant ingredients (vitamin E, C, niacinamide) have also been incorporated into the formulas for additional protection against free radicals generated by radiation, and "booster" ingredients that enhance the effectiveness of the SPF.
Even gradual release technologies or longer water and sweat resistance are being explored, with extreme sports or prolonged outdoor use in mind.
Focus on safety and environment
Recent innovations consider not only efficacy but also safety for humans and the environment . Research is underway to identify filters that do not cause irritation or sensitization to sensitive skin, nor are they harmful to marine life. The debate over UV filters and coral reefs has prompted the search for "reef-friendly" filters.
Some tourist destinations have banned ingredients like oxybenzone due to their environmental impact. In response, many modern formulations avoid certain controversial filters and use alternatives with better environmental profiles.
Similarly, mineral filters (zinc and titanium), especially in non-nano form or with special coatings, are promoted as options with a lower environmental impact, although they come with the challenge of not leaving a whitening effect on the skin.
In short, the sunscreen industry is moving toward products that are more effective across the entire UV spectrum, more comfortable to use, and safer , relying on the advanced chemistry of new filters and constant formulation improvements. These innovations benefit both consumers (better protection and user experience) and professionals and regulators by facilitating compliance with increasingly demanding sun protection standards.
7 Common Myths About Using Sunscreen
Despite educational campaigns, many myths and misconceptions persist about when and how to use sunscreen. Clarifying these myths is essential so that the public can make the most of sun protection. Below, we debunk some of the most common myths:
Myth 1: “If I use sunscreen, I won’t tan.”
Sunscreen doesn't completely prevent tanning, but it filters out some of the UV radiation to make the process safer and slower. Tanning is the skin's defense response to UV damage (melanin darkens to absorb radiation), and therefore indicates damage .
With sunscreen, you can tan gradually, but it will reduce the risk of sunburn, premature aging, and cancer. A healthy tan doesn't actually exist; any tan is a sign of accumulated damage.
It's recommended to always use sunscreen (at least SPF 30) and moderate your sun exposure, seeking shade during peak hours. Your skin will tan more slowly, but will be more protected.
Myth 2: “Only SPF 50 (or higher) protects me; lower SPFs are useless.”
Any sunscreen with SPF 15 or higher can be effective if applied correctly and in sufficient quantity . The difference between SPF 30 and SPF 50 in percentage of UVB blocked is small (approximately 97% vs. 98%). A properly applied SPF 30 may protect better than a poorly applied SPF 50.
The important thing is to choose an SPF appropriate for the situation (minimum 30 for everyday use, 50 for prolonged outdoor activities) and apply the correct dose. SPF 50 doesn't mean you can spend twice as much time in the sun as with SPF 25, as it's not linear, and both require reapplying periodically.
In short, a high SPF offers more protection but isn't invincible; a medium SPF also offers good protection if used correctly. You should never let your guard down with any SPF.
Myth 3: “A very high SPF lasts all day, there’s no need to reapply.”
I wish it were true. No sunscreen lasts all day. Chemical filters degrade with UV exposure, and any product (chemical or mineral) can be removed by sweat, water, and rubbing against clothing or towels. An SPF 50+ applied at 9 a.m. will no longer provide that protection by midday if it's not reapplied.
All dermatologists recommend reapplying at least every two hours, or immediately after swimming or sweating heavily. This applies even to products labeled "water-resistant": water resistance doesn't mean it lasts indefinitely; it simply means that it retains some of its SPF after 40 to 80 minutes in the water, but much of the protection is lost when you get out and towel off.
Therefore, no sunscreen is "all-powerful"; reapplication and avoiding overexposure are still necessary with any SPF.
Myth 4: “Makeup with SPF replaces sunscreen.”
Many cosmetics (foundations, tinted moisturizers) include SPF in their formulas, which is beneficial. However, relying on makeup with SPF alone can be insufficient. The main reason is that we don't apply enough makeup to achieve the stated SPF protection .
SPF is calculated at 2 mg/cm², a much thicker layer than that typically used with foundation or powder. Furthermore, few makeup products offer adequate UVA protection. Ideally, you should use a dedicated sunscreen under your makeup, and consider the SPF of the makeup as an extra . If you're only going to be outdoors for a short time, SPF 30 makeup may offer partial protection, but for extended exposure, it's best to play it safe and apply a generous amount of real sunscreen.
Myth 5: “If I have brown (or dark) skin, I don’t need sunscreen.”
It's true that darker skin tones have more melanin, which provides natural protection equivalent to ~SPF 13 (depending on the skin tone) and makes sunburn less common. But no skin tone is immune to UV damage.
People with darker skin types can also suffer from photoaging , uneven hyperpigmentation, and, although less common, skin cancer (melanoma and others) due to accumulated damage. In fact, skin cancers in dark-skinned people are often detected late due to the false belief that "I don't burn."
All skin types need protection ; the difference will be in how easily they burn (a very fair person should use a very high SPF and reapply religiously; a dark-skinned person may not burn easily, but their skin still ages and suffers damage if not protected). Furthermore, current sunscreens are usually translucent and don't leave a noticeable white cast, so there's no aesthetic excuse not to use them on dark skin.
Myth 6: “If it’s cloudy or I’m in the shade, I don’t need sunscreen.”
False. Up to 80% of UV radiation can penetrate light cloud cover. Even if the heat isn't perceived on cloudy days, UV rays (especially UVA rays) still reach the sun and can cause damage. Many mild sunburns occur on cool days or when the sun is shining through the clouds because people don't protect themselves, thinking "there's no sun."
Likewise, in the shade, one is protected from direct radiation, but diffuse radiation reflected by the environment still exists. Sand, water, and even light-colored walls reflect UV rays. Therefore, even in the shade on the beach, it is recommended to wear sunscreen. The same is true when driving or standing indoors near windows in bright daylight, as UVA rays penetrate glass.
In short, 365-day-a-year sun protection is the advice of dermatologists: adapt the SPF to the UV intensity of each day, but don't skip it entirely because it's cloudy or you spend mostly in the shade.
Myth 7: “Sunscreens are dangerous/toxic”
This myth encompasses several concerns. Regarding cancer , there is no scientific evidence that regular sunscreen use causes cancer; on the contrary, it has been shown to prevent certain skin cancers by reducing the accumulated harmful radiation dose. Some studies in cells or animals have indicated compounds that may have weak hormonal effects (e.g., oxybenzone), but regulatory authorities evaluate these data and establish safe concentrations. The formulations undergo rigorous safety testing.
Regarding vitamin D , it's true that UVB rays help synthesize it in the skin, but using sunscreen doesn't cause significant deficiency in most people. This is because no one applies sunscreen perfectly at all times or in all areas (so some UV radiation always reaches us to produce vitamin D), and we can also obtain vitamin D from diet or supplements if needed. The benefits of sun protection in preventing cancer and aging far outweigh any minimal impact on vitamin D.
Finally, regarding allergies or toxicity: modern sunscreens are quite refined, and there are mineral or sensitive skin options for those wary of chemicals. In conclusion, sunscreens are safe when used as directed and are a crucial public health tool.
(There are more myths, but the above are some of the most common. The important thing is to seek reliable information and follow the recommendations of dermatology professionals.)
Practical recommendations for consumers: how to choose and apply sunscreen correctly
To get the most out of sunscreen, consumers should consider several factors when choosing and using the product . Here are some practical recommendations:
Prefers “broad spectrum” formulas
Make sure the packaging indicates both UVB and UVA protection. Look for the circular UVA symbol (on European products) or the phrase "broad spectrum" on other markets. This ensures that the product meets minimum UVA protection standards, in addition to the UVB SPF.
Choose an SPF suitable for your activity
For everyday use (everyday city activities, walking to work, etc.) , SPF 30 or higher is typically recommended. If you're going to be outdoors for long periods of time, playing sports at the beach or in the mountains, opt for SPF 50+ and reapply frequently. Remember that higher SPFs offer more protection but aren't foolproof —don't prolong your sun exposure thinking that sunscreen makes you invulnerable.
Take into account your skin type
If you have sensitive skin or allergies, consider using physical/mineral sunscreens (zinc oxide or titanium dioxide) or hypoallergenic formulas, as they tend to be better tolerated. If you have oily or acne-prone skin, look for non-comedogenic , oil-free products, such as mattifying gels or fluids. For dry skin, a cream with hydrating ingredients will be helpful. For darker skin, you may prefer sheer or tinted formulas to avoid any white cast from mineral filters.
Check water resistance if needed
If you're going to be swimming, doing intense sports, or sweating, choose a water-resistant sunscreen. These indicate that they retain some of their protection after a certain amount of time in the water (40 or 80 minutes), which is essential for water activities or exercise. Still, remember that "water-resistant" doesn't mean "waterproof": you'll need to reapply after getting wet or drying off.
Check the expiration date
Sunscreens expire ; their filters can degrade over time. Use products within the date indicated (or within 12, 18, etc., after opening, according to the PAO symbol). An expired sunscreen may have lost its effectiveness. Also, store it in a cool place away from direct sunlight when not in use to prevent premature deterioration.
When applying sunscreen:
Apply sufficient quantity
This is perhaps the most important and underrated step. SPF efficacy is determined at ~2 mg/cm², which is roughly equivalent to one teaspoon for the face/neck or about 30 ml (a shot glass) to cover an adult body in a bathing suit . A good rule of thumb is the “two-finger rule” : for each area (each arm, each leg, torso, back, face/neck), apply two lines of cream along your index and middle fingers as a guide to the approximate amount needed. Don’t skimp on the product; applying less drastically reduces protection.
Apply evenly
Spread the sunscreen evenly over the entire exposed area. Don't forget frequently overlooked areas : ears, neck, back of the hands, insteps of the feet, hairline, lips (use lip balm with SPF), and behind the knees. Ask for help for tricky areas like the back. Careless application can leave unprotected patches that will burn.
Application time
Apply sunscreen about 20-30 minutes before sun exposure, especially if it's a chemical sunscreen, so it has time to absorb properly. If you use a mineral sunscreen, the protection is effective immediately upon application, but it's also helpful to apply it beforehand to ensure full coverage. If you're going to wear makeup, apply sunscreen first, let it sit for a few minutes, and then apply your makeup.
Reapply frequently
As explained in the myths section, sunscreen diminishes over time. Reapply at least every two hours under normal conditions. If you're at the beach, pool, or exercising in intense sun, it's advisable to reapply every 90 minutes. And always reapply after swimming, toweling off, or sweating profusely (even if the product is water-resistant). Keep sunscreen handy to replenish throughout the day.
To avoid ruining your makeup when reapplying, you can use sprays or mists on your face, or powders with SPF, but be sure to apply enough or wear a hat for maximum protection.
Combine with other protective measures
Sunscreen shouldn't be your only defense. Maximize protection by also wearing appropriate clothing (a wide-brimmed hat, UV sunglasses, long clothing, or UPF-protected fabric if possible) and seeking shade during the most intense hours of sunlight (between 12:00 and 16:00). Remember that the day's UV index can help you plan: if it's very high/extreme, limit your exposure even if you're wearing sunscreen. Sunscreen works best as part of a comprehensive sun protection strategy.
By following these tips, consumers can significantly reduce the risks associated with sun exposure. The key is consistency (daily protection, even on cloudy days) and generous, repeated application of the product. Your skin's long-term health will thank you for it.
Recommendations for formulating companies: regulatory compliance, labeling and testing
For professionals and companies that develop and market sunscreens, in addition to the scientific aspects, it is crucial to comply with regulations and ensure the quality and efficacy of the final product. Here are some key recommendations for formulators in the sunscreen cosmetics sector:
Comply with ingredient regulations
Verify that all UV filters in the formula are authorized by the regulations of the destination market . In the EU, only filters listed in Annex VI of the Cosmetics Regulation may be used, within their permitted concentrations.
Stay up-to-date with regulatory updates. If you formulate for global markets, be aware of the differences: e.g., in the U.S., the range of filters approved by the FDA is more limited. Offering "global" formulas may require adjusting filters based on the region.
Balance the formula for broad spectrum
From the formula design, be sure to include a combination of filters that achieves the goal of UVA PF ≥ 1/3 SPF .
This often involves combining high-performance UVB filters with deep UVA filters.
Use spectral absorption data from each filter to synergistically cover the 290-400 nm spectrum as evenly as possible. Also, remember to achieve a critical wavelength ≥ 370 nm to be able to claim UVA protection in Europe.
Photostability and compatibility
Check the photostability of the filter combination. Some filters can degrade each other (for example, avobenzone is stabilized with octocrylene, but may degrade without stabilizers). Conduct UV exposure tests on the formulation to ensure that the SPF and UVA-PF are maintained after hours of irradiation (many standards require measuring SPF in vitro after irradiating the sample with a standard UV dose to assess stability). Also check the chemical compatibility of the filters with other ingredients (certain emulsifiers, perfumes, or plant extracts can interact with filters, affecting color or odor over time).
Mandatory efficacy trials
Plan and execute the tests necessary to validate the claims :
SPF
The reference method is the in vivo test in volunteers (minimum 10 subjects) applying 2 mg/cm² and determining the SPF by comparative MED (ISO 24444). Alternatively, in vitro methods (ISO 24443 uses spectrophotometry) can help in the development stages, but most authorities still require in vivo data for labeling.
GRAPE
If you're using the UVA logo, perform the in vitro UVA-PF test (e.g., ISO 24443 method or the in vivo PPD method ISO 24442). Make sure you get a UVA-PF value ≥ 1/3 of the SPF. Also, check the critical wavelength with a spectrophotometer (ISO 29063 method) to confirm that you achieve ≥ 370 nm.
Water resistance: If you're going to claim "Water Resistant" or "Very Water Resistant," carry out the appropriate test (usually measuring the SPF before and after standardized immersion in water, according to COLIPA/ISO guidelines). Only make these claims if the results meet the criteria (e.g., maintaining at least 50% of the SPF after two 20-minute immersions for "water resistant").
Stability and security
In addition to UV efficacy, like any cosmetic , physical-chemical stability tests must be carried out (resistance to temperature cycles, centrifugation, etc.), packaging compatibility (that the plastic of the tube does not interact with the formula), and microbiological tests (antimicrobial challenge) given that these are products that can become contaminated with frequent use on the beach, etc.
Likewise, conduct usage or sensitivity studies on people (irritation, allergy, ophthalmological tests if for the face) to validate that the product is well tolerated.
Clear and standard-compliant labeling
On the packaging, follow the labeling recommendations: Clearly indicate the SPF and category (“High,” “Very High,” etc., optionally).
Include the circled UVA symbol if applicable (and only if applicable, meaning you passed the tests). Incorrect labeling could be considered false advertising and result in penalties.
Add usage instructions : “apply 20 minutes before,” “reapply every 2 hours,” “use generously,” “for external use only – avoid contact with eyes,” etc., to educate the user on proper use. Many markets require some standard phrases (“reapply frequently,” “avoid prolonged sun exposure even with sunscreen,” “keep babies out of direct sunlight,” etc.).
Complete list of ingredients (INCI) , including the [nano] label on physical filters if they are nanoparticles. And don't forget the batch number, expiration date or PAO, and contents (ml).
Quality and batch control
Implement rigorous quality control during production to ensure that each batch of sunscreen actually meets the labeled SPF. Variations in raw materials or processes could affect performance (e.g., particle size of a mineral filter, or strength of an organic filter). Ideally, conduct in vitro SPF testing on pilot batches regularly, and at least one in vivo test on a commercial batch occasionally, to ensure consistency. Also monitor shelf-life stability of batches throughout their shelf life.
Documentation for authorities
Prepare and maintain an up-to-date Product Information File (PIF) with all formula, safety, and efficacy data. In the EU, this includes the cosmetic safety report and toxicological evaluations of each ingredient (paying special attention to UV filters, ensuring the combined concentrations comply with the law). Have SPF/UVA test reports ready. This way, you can transparently demonstrate compliance during any inspection or request from health authorities.
Innovation and differentials
From a technical marketing perspective, highlighting innovations can provide a competitive edge. But make sure any innovative claims are supported: for example, if you say "protects against blue light," you should have studies or filters that effectively cover up to 400–500 nm, or if you say "respects the oceans," you should have avoided ingredients banned by local regulations (such as Hawaii) and perhaps undergone eco-toxicological tests. Communication must be responsible so as not to create new myths or create consumer confusion.
Ultimately, the task for formulating companies is twofold : on the one hand, scientific and technical , to develop an effective and safe product; on the other, regulatory and educational, to comply with laws while guiding the user in proper use through labeling.
A well-formulated and properly tested sunscreen not only prevents burns and skin damage, but also builds trust among consumers and healthcare professionals, strengthening the brand's reputation and contributing to public health.
Conclusion
In this guide, we've reviewed in detail what SPF is and how it's measured, the importance of covering both UVB and UVA radiation, key regulatory requirements in the European Union (and comparisons with the US), and the latest innovations in filters. We also debunk common myths and offer practical recommendations for both consumers and formulators. Understanding and correctly applying these concepts not only guarantees the effectiveness of your formulas, but also protects the health of your users and ensures regulatory compliance.
Do you need expert support?
If you want to design, validate, or launch a sunscreen with all the guarantees of effectiveness and compliance with legislation, contact BELAB Services today . Our team of cosmetics and regulatory specialists will support you throughout every phase of the project to ensure your products meet the highest standards of quality and safety.
