SUNSCREEN: Let's Break it down
SUNSCREEN: Let's Break it down
- posted: Jul. 09, 2025
Understanding Chemical vs. Physical Sunscreens and What SPF Really Means
Sunscreen has been touted as your skin’s best friend when it comes to fending off harmful UV rays, which can lead to sunburn, wrinkles, and even skin cancer. Let’s dive deeper into the two main types of sunscreens—chemical and physical (often called mineral)—and unpack what those SPF numbers on the bottle actually tell you. Plus there are new concerns regarding sunscreen and how to navigate a healthier approach to sunscreen. Dr. Jeffrey Berti and Dr. Toula Berti of Nashville Dermatology Physicians are the ones who can help you understand the world of sunscreens!
How Do Chemical and Physical Sunscreens Work?
1. Physical (Mineral) Sunscreens:
- How They Protect: These use minerals like titanium dioxide or zinc oxide to create a shield on your skin. They work double duty: absorbing some UV rays (turning them into heat) and bouncing others away through reflection and scattering.
- UVA vs. UVB Coverage: Both, minerals offer broad-spectrum protection, but zinc oxide is a star at blocking UVA rays, which makes it a top pick for comprehensive coverage.
- Why People Like Them: Mineral sunscreens are gentle, making them great for sensitive skin or kids. They’re also less likely to harm marine life, which is a big plus for eco-conscious folks. The downside? They can be thicker and sometimes leave a white cast, though newer formulas are better at blending in.
La Roche-Posay Mineral Sunscreen and all Vanicream Sunscreens are great! La Roche-Posay tinted mineral wins for great application and coverage; however, Vanicream best for those with ultra sensitive skin.
- Heads-Up: Unlike chemical sunscreens, these start working the moment you apply them, so they’re perfect for spontaneous beach trips.
2. Chemical Sunscreens:
- How They Protect: These sunscreens use organic compounds like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate to soak up UV rays before they can damage your skin. The UV energy gets absorbed by these molecules, which then release it as harmless heat.
UVA vs. UVB Coverage: Each ingredient has a specific role:
- UVB Protection: Octisalate, homosalate, and octinoxate focus on blocking UVB rays, which cause sunburn and play a big role in skin cancer.
- UVA Protection: Avobenzone tackles UVA rays, which dig deeper into the skin, speeding up aging and contributing to long-term damage. Oxybenzone and octocrylene are versatile, covering both UVA and UVB.
Heads-Up: You need to apply these about 15–30 minutes before sun exposure to let them sink in and work properly.
-Why People Like Them: Chemical sunscreens tend to be lightweight, blend in clear, and feel less heavy, making them a go-to for everyday use. That said, some folks worry about ingredients like oxybenzone due to potential skin irritation or environmental concerns, like coral reef harm. Regulatory agencies, like the FDA, still approve these at safe levels, but it’s worth noting that those chemicals used are being looked at more closely....
Recent concerns about sunscreen safety, especially chemical sunscreens, you might be wondering what’s safe to slather on. Let’s clear up the confusion with straightforward facts to help you protect your skin confidently.
Why the Concern About Chemical Sunscreens?
Here’s what’s behind the buzz:
- Skin Sensitivity: Ingredients like oxybenzone can irritate sensitive skin for some people. If your skin gets red or itchy, a mineral sunscreen might be a better fit.
- Absorption Concerns: Studies show small amounts of chemical sunscreen ingredients can enter the bloodstream. The FDA says these levels are "safe," but research is ongoing to confirm long-term effects. Even "small amounts of chemicals" can pose potential risks so if this worries you, utilize mineral sunscreens that stay on the skin’s surface.
-Environmental Impact: Certain chemicals, like oxybenzone and octinoxate, have been linked to coral reef damage, leading to bans in places like Hawaii. Mineral sunscreens are generally more ocean-friendly.
Tips:
- Patch-Test: Try a small amount of sunscreen on your inner arm to check for irritation, rash or does this lead to acne (find small area on chest)
-Choose Broad-Spectrum: Pick Mineral sunscreen SPF 30 or higher that protects against UVA and UVB rays.
- Apply Correctly: Use on body if exposing to sun such as at a beach or on a boat and apply liberally every 2 hours.
However, there is no need to apply all over your body if only outside for 30 minutes or less as we know some sunlight is beneficial and can improve Vitamin D levels as well as your mood, sleep and general health!
Breaking Down SPF:
SPF, or Sun Protection Factor, tells you how well a sunscreen shields against UVB rays, the ones responsible for burning your skin. It’s a measure of how much longer you can stay in the sun without burning compared to unprotected skin, tested in a lab setting.
1. What SPF Measures:
- SPF is a multiplier of your skin’s natural burn time. For example:
- If your skin burns in 10 minutes without protection, SPF 15 extends that to 150 minutes (10 x 15).
- SPF 30 gives you 30 times longer, and so forth.
- Here’s how much UVB it blocks:
- SPF 15: ~93% of UVB rays.
- SPF 30: ~97%.
- SPF 50: ~98%.
- SPF 100: ~99%.
- Past SPF 50, you’re not getting much extra bang for your buck, so SPF 30–50 is usually plenty for most people.
2. SPF and UVA:
- SPF only measures UVB protection, not UVA, which causes deeper damage like wrinkles and age spots. For UVA, you need a **broad-spectrum** sunscreen, which covers both types of rays. In the U.S., broad-spectrum products are tested to ensure UVA protection matches their SPF level. Elsewhere, look for a UVA logo or PA rating (like PA+++ for strong UVA defense).
SPF Myths to Bust
- Higher SPF = Total Safety: No sunscreen blocks all UV rays. Even SPF 100 lets ~1% of UVB through.
- SPF Stacking: Using SPF 15 moisturizer plus SPF 15 sunscreen doesn’t equal SPF 30. You get the protection of the higher SPF, not a combo.
- All-Day Protection: No sunscreen lasts all day. Reapply, period.
At Nashville Dermatology Physicians, located in Brentwood, TN, Dr. Jeffrey Berti and Dr. Toula Berti are here to help you find the right sunscreen for your skin and lifestyle. Newer mineral formulas blend better and avoid that chalky look, even for darker skin tones.
Have questions or need a personalized recommendation?
Request an appointment here on our website or call to schedule a consultation: 615.212.2517.
We proudly serve the greater Nashville area with easy access off of I-65, exiting Old Hickory Blvd east and we are simply a few stop lights down.
SUNSCREEN: Let's Break it down
- posted: Jul. 09, 2025
Understanding Chemical vs. Physical Sunscreens and What SPF Really Means
Sunscreen has been touted as your skin’s best friend when it comes to fending off harmful UV rays, which can lead to sunburn, wrinkles, and even skin cancer. Let’s dive deeper into the two main types of sunscreens—chemical and physical (often called mineral)—and unpack what those SPF numbers on the bottle actually tell you. Plus there are new concerns regarding sunscreen and how to navigate a healthier approach to sunscreen. Dr. Jeffrey Berti and Dr. Toula Berti of Nashville Dermatology Physicians are the ones who can help you understand the world of sunscreens!
How Do Chemical and Physical Sunscreens Work?
1. Physical (Mineral) Sunscreens:
- How They Protect: These use minerals like titanium dioxide or zinc oxide to create a shield on your skin. They work double duty: absorbing some UV rays (turning them into heat) and bouncing others away through reflection and scattering.
- UVA vs. UVB Coverage: Both, minerals offer broad-spectrum protection, but zinc oxide is a star at blocking UVA rays, which makes it a top pick for comprehensive coverage.
- Why People Like Them: Mineral sunscreens are gentle, making them great for sensitive skin or kids. They’re also less likely to harm marine life, which is a big plus for eco-conscious folks. The downside? They can be thicker and sometimes leave a white cast, though newer formulas are better at blending in.
La Roche-Posay Mineral Sunscreen and all Vanicream Sunscreens are great! La Roche-Posay tinted mineral wins for great application and coverage; however, Vanicream best for those with ultra sensitive skin.
- Heads-Up: Unlike chemical sunscreens, these start working the moment you apply them, so they’re perfect for spontaneous beach trips.
2. Chemical Sunscreens:
- How They Protect: These sunscreens use organic compounds like oxybenzone, avobenzone, octisalate, octocrylene, homosalate, or octinoxate to soak up UV rays before they can damage your skin. The UV energy gets absorbed by these molecules, which then release it as harmless heat.
UVA vs. UVB Coverage: Each ingredient has a specific role:
- UVB Protection: Octisalate, homosalate, and octinoxate focus on blocking UVB rays, which cause sunburn and play a big role in skin cancer.
- UVA Protection: Avobenzone tackles UVA rays, which dig deeper into the skin, speeding up aging and contributing to long-term damage. Oxybenzone and octocrylene are versatile, covering both UVA and UVB.
Heads-Up: You need to apply these about 15–30 minutes before sun exposure to let them sink in and work properly.
-Why People Like Them: Chemical sunscreens tend to be lightweight, blend in clear, and feel less heavy, making them a go-to for everyday use. That said, some folks worry about ingredients like oxybenzone due to potential skin irritation or environmental concerns, like coral reef harm. Regulatory agencies, like the FDA, still approve these at safe levels, but it’s worth noting that those chemicals used are being looked at more closely....
Recent concerns about sunscreen safety, especially chemical sunscreens, you might be wondering what’s safe to slather on. Let’s clear up the confusion with straightforward facts to help you protect your skin confidently.
Why the Concern About Chemical Sunscreens?
Here’s what’s behind the buzz:
- Skin Sensitivity: Ingredients like oxybenzone can irritate sensitive skin for some people. If your skin gets red or itchy, a mineral sunscreen might be a better fit.
- Absorption Concerns: Studies show small amounts of chemical sunscreen ingredients can enter the bloodstream. The FDA says these levels are "safe," but research is ongoing to confirm long-term effects. Even "small amounts of chemicals" can pose potential risks so if this worries you, utilize mineral sunscreens that stay on the skin’s surface.
-Environmental Impact: Certain chemicals, like oxybenzone and octinoxate, have been linked to coral reef damage, leading to bans in places like Hawaii. Mineral sunscreens are generally more ocean-friendly.
Tips:
- Patch-Test: Try a small amount of sunscreen on your inner arm to check for irritation, rash or does this lead to acne (find small area on chest)
-Choose Broad-Spectrum: Pick Mineral sunscreen SPF 30 or higher that protects against UVA and UVB rays.
- Apply Correctly: Use on body if exposing to sun such as at a beach or on a boat and apply liberally every 2 hours.
However, there is no need to apply all over your body if only outside for 30 minutes or less as we know some sunlight is beneficial and can improve Vitamin D levels as well as your mood, sleep and general health!
Breaking Down SPF:
SPF, or Sun Protection Factor, tells you how well a sunscreen shields against UVB rays, the ones responsible for burning your skin. It’s a measure of how much longer you can stay in the sun without burning compared to unprotected skin, tested in a lab setting.
1. What SPF Measures:
- SPF is a multiplier of your skin’s natural burn time. For example:
- If your skin burns in 10 minutes without protection, SPF 15 extends that to 150 minutes (10 x 15).
- SPF 30 gives you 30 times longer, and so forth.
- Here’s how much UVB it blocks:
- SPF 15: ~93% of UVB rays.
- SPF 30: ~97%.
- SPF 50: ~98%.
- SPF 100: ~99%.
- Past SPF 50, you’re not getting much extra bang for your buck, so SPF 30–50 is usually plenty for most people.
2. SPF and UVA:
- SPF only measures UVB protection, not UVA, which causes deeper damage like wrinkles and age spots. For UVA, you need a **broad-spectrum** sunscreen, which covers both types of rays. In the U.S., broad-spectrum products are tested to ensure UVA protection matches their SPF level. Elsewhere, look for a UVA logo or PA rating (like PA+++ for strong UVA defense).
SPF Myths to Bust
- Higher SPF = Total Safety: No sunscreen blocks all UV rays. Even SPF 100 lets ~1% of UVB through.
- SPF Stacking: Using SPF 15 moisturizer plus SPF 15 sunscreen doesn’t equal SPF 30. You get the protection of the higher SPF, not a combo.
- All-Day Protection: No sunscreen lasts all day. Reapply, period.
At Nashville Dermatology Physicians, located in Brentwood, TN, Dr. Jeffrey Berti and Dr. Toula Berti are here to help you find the right sunscreen for your skin and lifestyle. Newer mineral formulas blend better and avoid that chalky look, even for darker skin tones.
Have questions or need a personalized recommendation?
Request an appointment here on our website or call to schedule a consultation: 615.212.2517.
We proudly serve the greater Nashville area with easy access off of I-65, exiting Old Hickory Blvd east and we are simply a few stop lights down.
Nashville Dermatology Physicians
1001 Health Park Drive Suite 470,
Brentwood, TN 37027
Monday
7:00 am - 4:00 pm
Tuesday
7:00 am - 4:00 pm
Wednesday
7:00 am - 4:00 pm
Thursday
11:00 am - 6:00 pm
Friday
Closed
Saturday
Closed
Sunday
Closed