Understanding Sunscreen Including the Different Types, Filters, and How They Work
Sunscreen is an essential part of any skincare routine, offering protection against the harmful effects of ultraviolet (UV) radiation. Whether you're hitting the beach or just walking outside, sunscreen acts as a barrier that shields your skin from sunburn, premature aging, and skin cancers caused by UV exposure. However, with so many options available, it can be difficult to know which sunscreen is best suited for your skin. In this article, we’ll explore what sunscreen is, the difference between mineral and chemical sunscreen filters, and a comprehensive list of sunscreen filters available today.
What is Sunscreen?
Sunscreen is a topical product designed to protect your skin from the sun’s ultraviolet radiation. UV rays are categorized into two types:
UVA: Responsible for premature skin aging and wrinkles. These rays penetrate deeply into the skin and are prevalent all year round, including on rainy or overcast days.
UVB: The primary cause of sunburn and can damage the outer layers of your skin. These rays are strongest in the summer.
Sunscreens typically contain active ingredients that either absorb or reflect UV rays to minimize skin damage. These ingredients fall into two broad categories: chemical (organic) filters and mineral (physical) filters.
Mineral vs. Chemical Sunscreen Filters
The key difference between mineral and chemical sunscreens lies in the way they protect your skin from UV rays:
Mineral Sunscreens (Physical Sunscreens)
How They Work:
Mineral sunscreens contain active ingredients such as zinc oxide and titanium dioxide. These act as a physical barrier on the skin, sitting on top and reflecting and scattering UV rays before they can penetrate the skin.
Benefits:
They provide immediate protection once applied, are generally less irritating, and tend to be less likely to cause breakouts, making them a good choice for sensitive skin.
Cons:
They can leave a white cast, especially on darker skin tones, and might feel heavier or thicker on the skin.
Chemical Sunscreens
How They Work:
Chemical sunscreens contain organic (carbon-based) compounds like oxybenzone, avobenzone, and octinoxate, which absorb UV rays and convert them into harmless heat, which is then released from the skin.
Benefits:
They tend to be lightweight and transparent on the skin, making them more comfortable to wear daily, especially under makeup.
Cons:
Some chemical filters can cause irritation or allergic reactions, especially for those with sensitive skin. They also need about 20-30 minutes to begin working after application. Additionally, certain chemical ingredients (e.g., oxybenzone) have raised concerns over their environmental impact, particularly on coral reefs.
Types of Sunscreen Filters: A Global Overview
There are numerous sunscreen filters used across the globe, and each is classified by its ability to protect against specific wavelengths of UV radiation. Some filters are approved for use in certain countries but not others, and the regulation of sunscreen ingredients varies worldwide. Below is a list of the most common sunscreen filters and a brief explanation of each.
1. Zinc Oxide
Type: Mineral (Physical) Filter
Protection: Broad-spectrum protection against both UVA and UVB.
Description: This is a staple in many mineral sunscreens. Zinc oxide provides excellent protection without causing skin irritation and is often found in formulations for sensitive skin.
2. Titanium Dioxide
Type: Mineral (Physical) Filter
Protection: Primarily UVB protection, but also offers some UVA protection.
Description: Like zinc oxide, titanium dioxide works as a physical blocker that reflects UV rays. It is often used in combination with zinc oxide for enhanced broad-spectrum protection.
3. Avobenzone
Type: Chemical (Organic) Filter
Protection: Primarily UVA protection (specifically UVA1 and UVA2).
Description: Avobenzone is a broad-spectrum UV filter and is one of the few chemical filters that offers full UVA protection. It is often used in combination with other filters to provide comprehensive sun protection.
4. Oxybenzone
Type: Chemical (Organic) Filter
Protection: Broad-spectrum (UVA and UVB).
Description: Oxybenzone is one of the most commonly used UV filters but has been controversial due to its potential to cause skin irritation and environmental concerns, especially regarding its effect on coral reefs.
5. Octinoxate (Ethylhexyl Methoxycinnamate)
Type: Chemical (Organic) Filter
Protection: Primarily UVB protection.
Description: This ingredient is frequently used to absorb UVB rays and prevent sunburn. It is widely used in many chemical sunscreens and is considered safe by most regulatory bodies but faces scrutiny for its environmental impact.
6. Octocrylene
Type: Chemical (Organic) Filter
Protection: Primarily UVB protection, some UVA coverage.
Description: Octocrylene is used to stabilize other sunscreen ingredients and provides moderate UVB protection. It's often included in formulas that are water-resistant.
7. Homosalate
Type: Chemical (Organic) Filter
Protection: UVB protection.
Description: Homosalate is a commonly used ingredient in sunscreens to absorb UVB rays. It’s often found in combination with other filters to achieve broad-spectrum protection.
8. Mexoryl SX (Ecamsule)
Type: Chemical (Organic) Filter
Protection: Broad-spectrum UVA protection.
Description: Mexoryl SX is known for its high level of UVA protection and is often used in Europe and Canada. It’s photostable, meaning it remains effective for longer periods under sun exposure.
9. Tinosorb S (Bemotrizinol)
Type: Chemical (Organic) Filter
Protection: Broad-spectrum (UVA and UVB).
Description: Tinosorb S is a highly effective filter that offers both UVA and UVB protection. It’s often considered superior in terms of photostability and is widely used in Europe but is not approved in the United States.
10. Tinosorb M (Tinosorb M)
Type: Chemical (Organic) Filter
Protection: Broad-spectrum (UVA and UVB).
Description: This filter offers both physical and chemical properties, providing excellent broad-spectrum protection. It is photostable and often used in combination with other ingredients to create more effective sunscreens.
11. Uvinul A Plus (Diethylamino Hydroxybenzoyl Hexyl Benzoate)
Type: Chemical (Organic) Filter
Protection: UVA protection.
Description: Uvinul A Plus is a chemical sunscreen filter that provides broad-spectrum UVA protection. It is photostable and frequently used in formulations for sensitive skin.
12. Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine (BEMT)
Type: Chemical (Organic) Filter
Protection: Broad-spectrum (UVA and UVB).
Description: This advanced filter offers both UVA and UVB protection and is commonly used in European sunscreens. It’s considered one of the most stable and effective filters.
13. Drometrizole Trisiloxane
Type: Chemical (Organic) Filter
Protection: Broad-spectrum protection, especially UVB.
Description: Often used in water-resistant sunscreens, it provides long-lasting protection against UV rays and is photostable.
14. Benzophenone-3 (Oxybenzone)
Type: Chemical (Organic) Filter
Protection: Broad-spectrum protection (UVA and UVB).
Description: Used widely in sunscreens for its UV-absorbing properties, it has raised environmental concerns due to its potential to harm marine life.
While mineral sunscreens are great for sensitive skin and provide immediate protection, chemical sunscreens are often more cosmetically elegant, lightweight, and easier to apply. Understanding the wide variety of sunscreen filters available, from common ones like zinc oxide and avobenzone to newer, advanced ones like Tinosorb S and Mexoryl, allows you to choose a sunscreen that best meets your needs, whether for daily use or an intense day in the sun.
Always remember to reapply sunscreen every two hours and after swimming or sweating, and pair it with other sun safety practices like wearing hats and sun protective clothing, avoiding going outside between 10-2 when the UV index is high, and seeking shade when possible.