Sunscreen Vs. Sunblock, What’s The Difference?

Sunblock? Between the overwhelming choices for sun protection products out there, finding the right product can be challenging. What most consumers don’t know is that there are distinct differences and benefits between sunblock and sunscreen. Here’s the lingo you need to know:

The Lingo

SPF stands for Sun Protection Factor and is used to estimate the amount of UV radiation it normally takes to sunburn one’s skin with protective sunscreen. The “A” in UVA stands for ‘Aging’. The “B” in UVB stands for ‘Burning’.


There are two types of protective lotions – chemical and physical.

Sunblock, the physical kind, contains both organic and non-organic ingredients that sit on top of the skin acting as a barrier between your skin and damaging UV rays by reflecting or scattering UVB light. Look for products with octyl methoxycinnamate, octyl salicylate and octocrylene.

Sunscreen, the chemical kind, penetrates the skin and absorbs the UVA rays before they are able to reach and damage your dermal layer. Zinc oxide and titanium dioxide are the active ingredients in deflecting harmful UV rays before they reach the protective outer epidermis layer of your skin. Another ingredient to look for is ecamsule, which is a photostable sun protectant that blocks out photoaging UVA rays.

Sunblocks are formulated to shield against UVB rays, while sunscreens protect against UVA. In order to fully protect your skin, choose a broad-spectrum protection formulated sunscreen that will protect against both UVA and UVB rays. Luckily these days, formulas often contain a mixture of both sunblock and sunscreen.

How to slather?

Contrary to belief, layering on both sunblock and sunscreen does not provide additional protection.

Ideally, sunscreen should be applied at least 30 minutes prior to sun exposure to allow it to be fully absorbed into the skin.

The daily amount of sun lotion recommended is about 1 ounce (roughly the size of a shot glass). Studies show that on average, people use only 20%-50% the recommended amount of sunscreen, diminishing the quality of protection received. So be sure to slather liberally and allow time for absorption.

To Reapply or Not to Reapply?

Consider your personal needs and habits when deciding the best sun protectant. You may also need to consider your application depending on activity level. For instance, if you’ll be in the water or sweating a lot, it is best to reapply frequently. Sensitive skin may fare better with sunblock since titanium dioxide and zinc oxide are less irritating than some ingredients found in sunscreen.

Adding sunscreen to your daily routine can block UVA, promoting graceful aging and UVB, which can keep your skin from burning. With this new knowledge you can safely minimize your sun exposure risk and choose the right sunblock to best fit your lifestyle.