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The Importance of Sunscreen

It's always been advised to put on sunscreen, ever since childhood. Have you ever wondered what exactly sunscreen is? Why should we put it? And how should we apply? Most of us know the importance of putting on sunscreen in the summer season to avoid sunburn. However, is this enough? Let’s learn the importance of sunscreen and protecting our skin.

Ultraviolet Radiation

Before breaking down the sunscreen component, we must learn about ultraviolet (UV) radiation from the sun. UV light ray is part of the electromagnetic spectrum which has a shorter wavelength than visible light which means our eyes can’t see it. A moderate amount of UV radiation increases vitamin D production, which aids the body in absorbing calcium and phosphorus from food. This can assist bone development and possibly prevent osteoporosis. The World Health Organization (WHO) recommends 5 to 15 minutes of sun exposure 2 to 3 times a week.

On any sunscreen products, UVA and UVB are common in the description. Both types are pronged to lead to skin cancer. UVA (longer wavelength) is associated with skin aging, while UVB (shorter wavelength) is associated with skin burning. Both UV rays may damage skin cells, alter the DNA and create mutations that can lead to skin cancer. UV radiation has been shown to cause basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), which are types of skin cancer and often appear on sun-exposed areas of skin.

Skin cancer is one of the most common cancers in the United States and around the world. The three main types are basal cell carcinoma, squamous cell carcinoma, and melanoma. 1 in 5 Americans develop skin cancer by the age of 70. Basal cell carcinoma and squamous cell carcinoma are the less severe forms, and they can usually be treated. About 90% of nonmelanoma skin cancers are associated with exposure to UV radiation from the sun. On the other hand, melanoma is the most severe form and causes 75% of skin cancer deaths. Without treatment, it can spread to other organs.

What Exactly is Sunscreen?

There are two types of sunscreen filters in the market - mineral (or physical) sunscreen and chemical sunscreen. The main difference between them is the ingredients. There are also standard features on sunscreen products - broad spectrum and SPF.

1. Mineral Sunscreen

Mineral sunscreen is also called physical sunscreens because it acts as a physical barrier and reflects UV rays away from your body. It uses minerals as its active ingredients, such as zinc oxide and titanium dioxide. Both elements act as a mirror to reflect and absorb UV rays to avoid them penetrating the skin.

  • Pros

These ingredients are GRASE (generally recognized as safe and effective) by the FDA for those concerned about the active chemical ingredients. It is also ideal for people with sensitive skin and melasma. It offers immediate protection, unlike chemical sunscreen, which requires 20-30 minutes of absorption.

  • Cons

Mineral ingredients usually leave a white film on the skin due to titanium dioxide and zinc oxide, which is not ideal, especially for people with darker skin. In addition, it needs to be reapplied more frequently than chemical sunscreens.

2. Chemical Sunscreen

The chemical ingredients in the sunscreen soak into the skin and absorb UV rays to prevent damage. A few common elements are oxybenzone, avobenzone, octinoxate, homosalate, octisalate and octocrylene.

  • Pros

It is quick and easier to apply, and they do not leave a white film on the skin.

  • Cons

The latest research from the Food and Drug Administration (FDA) tested 4 active ingredients (avobenzone, oxybenzone, octocrylene and ecamsule) that can stay in the bloodstream up to weeks which may cause prolonged effects and negative health effects. Another study from the FDA tested another three active ingredients (homosalate, octisalate and octinoxate) also entered the bloodstream and remained for long periods of time. A study conducted by University of Zurich found out that up to 76.5% of human breast milk samples contained at least one chemical ingredient from common sunscreen products. 47.1% of the milk sample found octocrylene. The levels remaining in the blood are significantly higher than the FDA threshold for safety. Thishas raised awareness of the health safety of the use of chemical sunscreen, especially for pregnant women and children. Oxybenzone has also been shown to cause coral bleaching. Furthermore, UV filters like 4-methylbenzylidene camphor, oxybenzone, octocrylene, and octinoxate have been found in various fish species, and it may impact the food chain.

3. SPF

SPF is an acronym for Sun Protection Factor, which is a measure of how long UVB rays cause sunburn. For instance, if you use an SPF 30 product, it would take you 30 times longer to get burned than if you do not use any sunscreen. SPF blocks up to 97% of UVB rays while SPF 50 blocks up to 98%. A higher value does not mean better protection.

4. Broad Spectrum Protection

In the past, people were taught that only UVB rays, associated with sunburn, caused damage. However, studies have shown the UVA rays cause skin aging; broad-spectrum sunscreen means that the product protects both UVA and UVB.

After the two clinical studies, on February 21, 2019, the FDA announced a new proposal regarding sunscreen. One of the proposals is that 16 marketed active ingredients have to be categorised as GRACE (generally recognized as safe and effective), Not GRASE and insufficient safety data. Only zinc oxide and titanium dioxide are GRASE while Aminobenzoic acid (PABA) and trolamine salicylate are, Not GRASE. The remaining 12 will need further data. The American Academy of Dermatology Association recommended sunscreen that has broad-spectrum protection, SPF 30 or higher and water resistance.


Even though the potential health risk of chemical sunscreen may be traumatizing, putting something on is better than none. Here are some guidelines on how to use sunscreen.

  • Apply ENOUGH sunscreen to cover all skin that cannot be covered.

Most people only apply 25-50% of the recommended amount. Most adults need about 1 ounce to cover the skin fully. Remember to apply on the nose, ears, neck, hands, feet and lips.

  • Reapply at least every two hours.

When you are outdoors, it is essential to reapply often. Reapply more frequently if you are swimming or sweating. Follow the instructions on the product.

  • No sunscreen is waterproof.

All sunscreens can be washed off. The water-resistant label only means how long it remains effective for 40 or 80 minutes when swimming or sweating.

Up to 80% of the sun's rays can penetrate clouds. It is important to apply sunscreen daily regardless of the weather conditions even, during the winter months. Snow can reflect UV rays. Moreover, the higher the altitude, the greater the UV exposures. UV rays can also penetrate through windows, so you also have to apply sunscreen indoors.

Sunscreen alone cannot fully protect you from UV rays. The following are some additional protection.

  • Wear additional clothing to protect from the sun

Dress in a lightweight long-sleeved shirt and pants to limit sun exposure. Wear sunglasses or a broad-brimmed hat if possible. Choose sunglasses with a UV400 rating or 100% UV protection on the label.

  • Stay in the shade

The sun’s rays are most intense between 10 am and 2pm. Try to limit your time in the sun.

  • Get vitamin D safely.

Try not to rely on the sun to seek vitamin D. Take it through your diet or supplements.

  • Avoid tanning beds

UV light from the sun and tanning beds may cause skin cancer and wrinkling. It has a 75% increased risk of developing melanoma from one indoor tanning session. It damages your skin cells and accelerates symptoms of aging.

  • Be careful near water, snow, and sand.

These materials can reflect damaging rays from the sun, which can increase the chance of sunburn.

Overall, sunscreen is vital to our skin and health. It prevents skin cancer and aging skin. Learning the ingredients and labels on sunscreen is essential. Try to seek a dermatologist if you have concerns about your skin condition and health. But still, go and enjoy the outdoor activities during the summer. I hope you will have a fantastic summer!

Article Author: Michelle Lam

Article Editors: Stephanie Sahadeo, Edie Whittington