Sunscreens are essential products for protecting the skin from the sun’s ultraviolet (UV) rays , which can cause sunburn , cell damage , and increase the risk of skin cancer . They work by blocking or absorbing UV rays using various sunscreens . This article explores the composition of sunscreens, how they protect against UV rays, and the different types of sunscreens available on the market.
1. Why Use Sunscreens?
Sun exposure poses many dangers to the skin. Sunscreens help protect the skin from the harmful effects of UV rays, which fall into two main categories:
- UVA (wavelength 320-400 nm): Penetrates deep into the skin, contributing to premature aging and increasing the risk of skin cancer.
- UVB (wavelength 280 to 320 nm): Mainly responsible for sunburn and immediate damage to skin cell DNA.
Regular use of sunscreen helps reduce the risk of skin cancer , prevent sunburn and prevent premature aging .
2. Composition of Sun Creams
Sunscreens are composed of a mixture of active agents (sun filters) and excipients (inactive substances such as emollients, preservatives, and stabilizers) which ensure the correct texture and effectiveness of the product.
2.1 Solar Filters
Sunscreens are the active ingredients that protect the skin from UV rays. They fall into two main categories :
- Chemical (organic) filters : These filters absorb UV rays and convert them into heat, preventing UV rays from damaging the skin. Chemical filters include compounds such as:
- Avobenzone (absorbs UVA rays)
- Octocrylene (absorbs UVB)
- Oxybenzone (absorbs UVA and UVB)
- Mineral (inorganic) filters : These filters form a physical barrier that reflects or diffuses UV rays. The main mineral filters are:
- Zinc oxide (UVA and UVB protection)
- Titanium dioxide (UVB protection)
Modern sunscreens often contain a combination of chemical and mineral filters to provide complete protection against UVA and UVB rays.
2.2 Moisturizing and Emollient Agents
Sunscreens contain moisturizing agents , such as glycerin or panthenol , to hydrate the skin and prevent dryness, often caused by sun exposure. Emollients help soften and smooth the skin.
2.3 Preservatives and Stabilizers
To ensure product stability and durability, preservatives such as parabens or alternatives such as phenoxyethanol are added. They prevent the growth of microorganisms in the product, especially in water-resistant formulations.
2.4 Perfumes and Colorants
Fragrances are sometimes included to make application more pleasant, and colorants can be used to give some sunscreens a slightly tanned tint. However, fragrance- and colorant-free products are often preferred by those with sensitive skin .
3. Sun Protection Factor (SPF): How Does It Work?
The Sun Protection Factor (SPF) measures a sunscreen’s ability to protect the skin from UVB rays , which cause sunburn. For example, an SPF of 30 allows a person to be exposed to the sun 30 times longer without burning compared to unprotected skin.
- SPF 15 : Blocks approximately 93% of UVB rays.
- SPF 30 : Blocks approximately 97% of UVB rays.
- SPF 50 : Blocks approximately 98% of UVB rays.
Visual example:
- Sunscreen with SPF protection : Sunscreen with SPF 50, indicating high protection.
However, SPF only measures protection against UVB rays. For complete protection, it is important to use broad-spectrum protection , which also covers UVA rays .
4. Types of Sunscreens and Formulations
There are a wide variety of sunscreens, formulated to meet specific sun protection and skin care needs.
4.1 Mineral Sunscreens
Mineral sunscreens ( or physical sunscreens) use filters like zinc oxide and titanium dioxide to form a physical barrier on the skin. They are particularly suitable for sensitive skin because they are less likely to cause allergic reactions.
4.2 Chemical Sunscreens
Chemical sunscreens are quickly absorbed by the skin and provide invisible protection . They contain organic filters such as avobenzone or oxybenzone. They are often lighter in texture than mineral sunscreens.
4.3 Water-Resistant Sunscreens
Water-resistant sunscreens are designed to remain effective even after prolonged exposure to water or sweat. They are ideal for outdoor activities, such as swimming or sports .
4.4 Tinted Sunscreens
Tinted sunscreens contain pigments that give the skin a slightly tanned effect while providing UV protection. They are often used as an alternative to foundation during the summer months.
5. How to Apply Sunscreen Correctly?
For effective protection, it is important to apply sunscreen properly and regularly.
5.1 Quantity to Apply
It is recommended to apply enough sunscreen to cover the entire body. On average, about 30 mL (the equivalent of a small glass) of sunscreen is needed to cover an adult.
5.2 Frequency of Reapplication
Sunscreen should be reapplied every two hours , or after swimming or excessive sweating, even if it is water-resistant.
5.3 Often Forgotten Areas
Certain areas of the body are often neglected when applying sunscreen, including:
- The ears
- The neck
- The feet
- The scalp (for bald people)
Visual example:
- Sunscreen Application : Correct application of sunscreen to protect against sunburn.
6. Advantages and Limitations of Sunscreens
6.1 Advantages :
- UV Protection : Effectively protects against UVA and UVB rays, reducing the risk of skin cancer.
- Skin Aging Prevention : Helps prevent premature aging and the appearance of wrinkles caused by sun damage.
- Versatility : Available in different forms (creams, sprays, lotions) to suit various skin types and needs.
6.2 Limits :
- Possible allergic reactions : Some people may react to chemical filters or preservatives in some sunscreens.
- Environmental impact : Some chemical filters, such as oxybenzone , are harmful to marine ecosystems, especially corals . Many countries ban these substances from sunscreens.
- Frequent reapplication : Requires regular application, which can be cumbersome.
7. Innovations and Sustainable Alternatives
With the emphasis on environmental protection , new, more nature-friendly formulations are emerging.
7.1 Eco-responsible Sunscreens
Eco-friendly sunscreens use non -nano-particle mineral filters (non-nano zinc oxide), which are safe for the environment and respectful of marine ecosystems.
7.2 Vegan and Natural Sunscreens
These sunscreens use natural ingredients , no animal products, and are free from harsh chemical preservatives, scented with essential oils rather than synthetic fragrances.
Conclusion: Essential Protection Against the Dangers of the Sun
Sunscreens are an essential tool for protecting skin from UV damage . Whether it’s to prevent sunburn , avoid premature aging , or reduce the risk of skin cancer , they play a crucial role in daily skin care. Regular use of sunscreens , combined with proper application and appropriate protection for outdoor activities, is the key to maintaining long-term skin health.
