Medically reviewed by Minimalist Health Specialist -  Written by Arpita Singh (Beauty Expert)  on 19th Oct 2020

Sunscreen Vs. Sunblock: Here's the difference

Sunscreen Vs. Sunblock

Do you apply your sunscreen only once before stepping out and don't reapply throughout the day? If so, you might be making a big blunder.

Also, you may have oily, dry, or combination skin. Alternatively, you may suffer from a skin condition, which calls for using a particular sunscreen for all your needs. But if you are unaware of these facts and merely daubing on your skin whatever you get. You should consider looking at your skincare routine again and tweaking it a bit.

We have got you all covered here! Just keep on reading, and you will get all the  information you need about the proper use of sun protectants. Let us start with why it is essential to protect yourself from the sun in the first place. 

UV rays; the worst enemies to your skin!

Visible light, UV rays (or ultraviolet radiations), and heat are constituents of the sunlight.

UV rays can be classified/divided into three types, based on their wavelength. 

1) UVA 

  • Forming 95% of the UV rays that reach the earth's surface has the longest wavelength. 
  • It can penetrate the more profound parts/layers of skin.
  • The primary/major reason for the development of skin cancers. Also, helping in the signs of aging to show up on the surface, with wrinkles predominating. It causes immediate tanning.

2) UVB 

  • It has a shorter wavelength, and the ozone layer of the earth's atmosphere absorbs it to some degree. 
  • It doesn’t get into the deeper layers. Instead, it affects only the outer superficial layers of skin. 
  • It implicates the condition of skin cancers. Accelerates the process of skin aging. 

3) UVC 

  • It is blocked by the earth's atmosphere, and therefore, is not concerned with the natural light you get from the sun.
  • It has the shortest wavelength.

What harm do the UV rays do? 

Dr. Andrea Suarez, a board-certified dermatologist and skincare expert, Colorado, US, Says

Exposure to the sun is one thing we cannot avoid much. Sometimes, the hours we spend in the sun are prolonged. Work, vacation, or daily errands - whatever you call it. Being out in the sun for unwarranted periods, and that too, without any protection, can lead to skin health hazards. 

  • Sunburns are minor problems. However, they do inflict damage to the cells and vessels. They are getting repetitive burns to make the skin weak and prone to bruises. 
  • UV rays cause potential causes of skin cancer in many people. 
  • They harness free radicals in the skin, and their count swells high. Free radicals are unstable oxygen molecules, which, in search of electrons, disrupt healthy cells' DNA. Breakdown of collagen follows, and it tries to bring an early onset of aging.
    "The skin texture begins to degrade, its elasticity reduces, and discoloration may also occur," informs Dr. Suarez. 
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How can you protect yourself from the harmful rays of the sun?

Regarding skincare products, there are two different ways.

1) Sunscreen 

A "chemical" defense that sort of acts like a UV filter as it permeates into your skin. It doesn't completely block the UV rays but reduces the amount that comes in contact with your skin layers.

As you apply the sunscreen, it gets absorbed by your skin. It doesn't leave any noticeable trace on the surface.

The UV rays, digging their way into your skin, are caught by the sunscreen. It then, using a chemical reaction, attenuates their wavelengths and convert them to heat. They are thus, released from the skin. In simple words, the sunscreen tames the UV rays so that they don't affect or interact with the skin.

The sunscreen makes use of chemical, organic ingredients, which actively counter the UV rays. These are avobenzone, oxybenzone, and PABA (Para- amino benzoic acid), which help you against UVA rays. Others include octinoxate, octyl salicylate, ecamsule, octocrylene, fighting the UVB rays. 

2) Sunblock 

It's a "physical" defense that acts as a barrier on the surface of your skin. It acts as a shield, blocking the harmful rays of the sun.

It is advised to rub in the sunblock evenly on your skin and not miss any part of your body exposed to the sun. It has got a thicker consistency, so it becomes difficult to spread it flat on your skin. Also, it leaves a pasty, raw cast on the skin's surface.

A sunblock sits on the surface of your skin and forms an opaque layer on it. The sun rays falling on it get reflected and scatter away in different directions. They physically block the rays from entering your skin.

They have organic as well as mineral ingredients in their composition. The two most commonly used are zinc oxide (10% to 20%) and titanium dioxide

Note:

In the United States, the FDA banned using the term 'sunblock' onto the labels of approved products. "It further explained that sunblock could excel in protecting you from the sun, owing to its mix of ingredients and formula. But it still can't ensure a 100% guarantee; actually, no sun protectant does. Therefore, to prevent people from falling into wrong notions about the security these products provide, the FDA forbid the term itself," explains Adam Mamelak, a Texas-based dermatologist.

Sunscreen v/s Sunblock 

Is one better than the other? 

We present to you the scientific facts and opinions from professional experts. 

● What does the research say? 

  • A 2013 study on Caucasian women concludes, "UV exposure seems to be responsible for 80% of visible facial aging signs." 
  • In February 2019, the FDA releases a statement wherein it accepts that out of the 16 active ingredients used in the making of sunscreens, 12 of them "have limited or no data characterizing their absorption." The ones under scrutiny are the ingredients found mainly in the chemical sun protectants. 
  • The FDA has published two studies in the years 2019 and 2020. They state that the ingredients, namely oxybenzone, avobenzone, octinoxate, and three more, are absorbed into the body even after a single-use. These chemicals circulate in the blood and at levels so high that they require an immediate investigation to be operated on the same. No piece of information exists that can answer our doubts about whether they are harmful to us. 

    Studies claim that the chemical ingredients could be found in the skin and blood, even after weeks of application. 
  • The Environmental Working Group has reviewed the existing data on 9 of the chemical ingredients used in the sunscreens. The most problematic proves out to be oxybenzone. Hence, the group cautions the general public against it as it may cause an allergic reaction. 

Note:

Note: The Indian regulatory agencies have not yet issued any exceptional guidance on sunscreen agents, as they are classified under cosmetics here.

● What do the dermatologists say? 

"The FDA has given the GRASE (Generally recognized as safe and effective) designation to only two of the active ingredients used in sun protection; they are zinc oxide and titanium dioxide.

These don't get absorbed into the bloodstream," informs Dr. Rhonda Q Klein, MD, Connecticut, US.
Many people find the two mineral ingredients reassuring for this reason. "They are well-tolerated by most of the sensitive skin types," says Dr. Klein.

Avobenzone, a chemical UV filter, highly photos unstable. It breaks down quickly, yet no actual data exists whether the products so formed are harmful to the body. It, for sure, needs stabilizers in the formula. 

Minimalist tip:

If you have an allergy-prone skin, avoid products with PABA, oxybenzone, preservatives, and fragrances! It may cause irritation or an allergy. Stinging, itching around the eyes also occur.

Dr. Vanita Rattan, a skincare expert, London, UK. suggests:

In the newer sun blocks coming out, the mineral components zinc oxide and titanium oxide are micronized, and they form the smaller nanoparticles. This may prevent the cast on the skin. But now, these blocks don't reflect the rays but absorb. The micronization renders them less effective, and the nanoparticles can be occlusive for the skin.

How do you apply sun-protection products? 

1. "Choose the product according to your skin type," reminds Dr. Rattan.

"If you have sensitive skin, or you suffer from rosacea, melasma, or skin conditions, don't use sunscreens (a.k.a ones acting as the chemical UV filters)."

"If you get acne frequently, don't go for a sunblock (a.k.a ones working as the physical barriers)."

These products come in various forms—lotions, creams, sticks, gels, oils, pastes, sprays, butter, etc. 

Caution:

Don't apply the sprays directly to your face. You may run a risk of inhaling its chemical ingredients. Follow the directions mentioned on the packaging.

2. Apply the sun protectant to dry skin 15-20 minutes before going outdoors. While you are out, it is mandatory to reapply the product every two hours to ensure continued protection.

3. Remember how you time your applications - it all depends on your personal needs, habits, activity (you may be swimming, or after a run, sweating profusely), and physical location in the world.

4. Apply it in liberal amounts on the tops of your feet, neck, ears, and the forehead. Most adults usually "take one ounce, or what is enough to fill a shot glass" to cover their bodies.

5. Please keep it away from direct sunlight. If you come across any change in smell, color, or consistency, you should discard the bottle right away.

Skin cancer can also affect one's lips. It is recommended to apply a lip balm or a lipstick that contains sun protection elements, having an SPF of 30 or higher. 

According to Elizabeth Buzney, MD, assistant professor of dermatology at Harvard Medical School

People, who have a dark complexion, get an advantage of huge stores of melanin in their skin, which naturally shield them against the sun. But it doesn't imply that they are in no need of sun protection altogether. Melanoma can still develop at places where melanin is lacking, such as the palms, soles, and fingers. So, use sunscreens irrespective of whatsoever.

The meaning behind some terms on the label 

1) Sun protection factor (SPF) 

SPF tells you how well a product can protect you from the sun's UVB radiations.

Let's say you have a product that is rated SPF 50. Now, what does the term "SPF 50" stand for? It indicates that the product can help you sustain the sun rays 50 times longer than the usual duration for which your skin can generally help itself without the protection.

Suppose you have sensitive skin. You can only tolerate the rays for 5 minutes. But as you rub in the product, it will allow you to spend (50×5) minutes outside in the sun. That, too, without any consideration of getting sunburns. Do keep in mind. It is a theoretical concept.

Usually, the doctors recommend using sun protectants with an SPF of 30 or more. But the higher SPFs only give fair better protection.

An SPF 30 product blocks 97% of the UVB rays hitting your skin. While an SPF 50 defends you against 98% of the beams. 

Caution:

Experts suggest not to use suntan lotion. It contains oil and mostly has an SPF of 15 or less. It may lead to acne. Also, some of the products claim they have insect-repelling ingredients in them. It is better to stay away from these products.

2) Water and Sweat related. 

The terms "waterproof" and "sweat-proof" have become outdated. Instead, "water-resistant" and "sweat-resistant" have been introduced onto the labels.

The manufacturer needs to mention the exact period up to which their product can remain effective against water, i.e., 40 minutes to 80 minutes mostly. 

3) Broad spectrum 

Products having a "broad spectrum" written over them are made to protect you against radiations, UVA, and UVB. It also lessens the damage that the blue light emitting from devices and appliances, do to your skin. 

The Bottom Line 

Masks have become an essential part of our clothing rituals, no matter what time we are going out. Experts advise using a thick moisturizer to prevent acne, popping on parts of the face covered by a mask. But masks won't provide you with sun protection, owing to their low SPF. You can use physical blockers (zinc oxide or titanium dioxide) to help yourself.

You will not find "sunblock" highlighted over a product. So, try and look for the mineral ingredients on the label to find one.

According to a recent Harvard study, you can follow other methods of sun protection as well. 

  • Wear UPF / SPF clothing. They include long, thick pants, full sleeves, etc. 
  • Put on hats with broad brims. 
  • Stay out of the sun. If possible, avoid outdoor activity between 10am to 4 pm. 

Using sunscreen daily, a necessity! Make it a habit to use them. If you put in efforts to preserve your skin, it will not fall prey to the UV radiation. Or lose all its luster. It will remain young and healthy for a long time