As the summer season warms up and people find themselves spending more time outside, it’s more important than ever to find the right sunscreen to protect skin from the sun’s damaging UVA and UVB rays. If you’ve spent more than a few seconds in any local grocery store or pharmacy over the past few months, you’ve likely seen shelves and shelves of sunscreen options getting stocked for summer. If you have no idea where to even begin choosing a sunscreen, Dr. Robert Marinaro of U.S. Dermatology Partners in Richardson and Sherman, Texas,  says, “There are several important factors to consider when it comes to choosing a sunscreen, but the difference between chemical and physical sunscreens is an important one that not everyone knows about. It’s essential to know the difference between the two products in order to use them correctly and avoid any unnecessary sun exposure.” In this blog, Dr. Marinaro will compare physical vs. chemical sunscreen as well as other important factors that should be considered when choosing a sunscreen.

What Is Physical Sunblock?
According to Dr. Marinaro, “People tend to use the words ‘sunscreen’ and ‘sunblock’ interchangeably. However, ‘sunblock’ most accurately refers to sun protection products that use minerals to physically block out the sun’s damaging ultraviolet (UV) rays.” Zinc oxide and titanium dioxide are common active ingredients in many types of sunblock, and these are the only sunblock ingredients that have been recognized by the U.S. Food and Drug Administration (FDA) as safe and effective. If you find a physical sunblock that lists other active ingredients, they may still be effective, but they have not been fully evaluated by the FDA.

What Is Chemical Sunscreen?
Chemical-based sunscreens don’t create a physical barrier between the skin and the sun’s damaging rays. Instead, these sunscreens use chemicals to filter out or absorb the sun’s UVA and UVB rays. Common chemical ingredients used in sunscreens include avobenzone, cinoxate, cioxybenzone, homosalate, meradimate, octocrylene, octinoxate, octisalate, oxybenzone, padimate O, ensulizole, and sulisobenzone.

Who Should Use Physical Sunblock?
When it comes to physical sunblock, Dr. Marinaro says, “Mineral sunblock offers broad-spectrum protection, which means it protects against UVA and UVB rays. Because it provides a physical barrier, you can go outside immediately after application.” Physical sunblock is recognized as safe and effective for use by:

• Infants and children
• Expectant and nursing mothers
• People with acne-prone skin (some mineral sunscreens even contain niacinamide, which is a vitamin B derivative that helps clear up active breakouts)
• Individuals with chronic skin conditions like eczema, psoriasis, and rosacea
• Individuals with sensitive skin

While mineral sunblock is safe enough for almost anyone, there are some potential drawbacks to these sunscreens. They do wash and rub off more easily than chemical sunscreens, so they may need to be reapplied more often. This is especially true if you’re going to be sweating or in the water. Typically, a thicker coating of mineral sunblock needs to be applied to ensure efficacy, which may leave skin looking chalky or impact the appearance of cosmetics.

Who Should Use Chemical Sunscreen?
Sunscreens that use chemicals to filter out and diffuse the sun’s ultraviolet rays can be extremely beneficial. They absorb more completely into the skin. The absorption process can take 15 to 20 minutes, so it’s important not to go outside until the product has been fully absorbed. The lightweight, easily absorbed chemical sunscreens are ideal for everyday wear, especially for individuals who use cosmetics. Additionally, chemical sunscreens are often beneficial for those who are going to be in the water or sweating as they are less likely to be washed off after they are fully absorbed into the skin.

Chemical sunscreens are not recommended for use by infants, children, or expectant mothers. They may also be more likely to cause irritation or inflammation to the skin, especially for those with sensitive skin or chronic skin conditions like acne, eczema, rosacea, and psoriasis. Those with sensitive skin typically should not use chemical sunscreens.

What Other Information Should I Look for on My Sunscreen Bottle?
In addition to knowing the difference between chemical and physical sunscreen, there are some other important factors to consider when choosing your sunblock, including:

• Broad-spectrum – This means the product protects from both UVA and UVB rays.
• Sun protection factor (SPF) – This number tells you how much additional protection, above the skin’s natural defensive barrier, sunscreen offers. In most cases, an SPF of 30 or higher is adequate.
• Water-resistant – Sunscreens marketed as water-resistant are less likely to be washed away even while engaging in sports or spending time in the water.
• Application method – Any sunblock application method (spray, lotion, cream, powder) should work well. This is a matter of personal preference. It’s always best to find a product you feel comfortable using regularly.

How Else Can I Prevent Sun Damage?
In addition to applying and reapplying sunscreen regularly, it’s important to take some additional steps to prevent sun damage, including:

• Take breaks from sun exposure by going indoors or seeking shade periodically
• Wear long-sleeved shirts and/or long pants to protect skin from sun damage
• Avoid or minimize sun exposure between 10 am and 4 pm when the sun’s rays are strongest
• Complete regular skin self-exams to check for any changes in the skin, especially new, evolving, or irregular spots on the skin
• Visit the dermatologist once each year for a professional skin exam