How Does Sunscreen Work?

The value of protecting your skin against the risks of sun exposure is something that’s rarely lost on anyone. But while we know that applying sunscreen each time you head outdoors is one of the most important things you can do to protect your skin from harmful ultraviolet (UV) damage, have you ever wondered exactly how sunscreen works to protect against the sun’s powerful rays?

In this article, we’ll answer the basics like “How does sunscreen work?”, while also considering other important factors such as vitamin D production, tanning, sunscreen expiry dates and how the various types of sunscreen products differ in their effectiveness.

Let’s dive into the science behind sunscreen and uncover its secrets to keeping our skin safe under the sun… 

• Understanding Sunscreen Functionality: Sunscreen, a blend of organic and inorganic compounds, protects the skin from harmful UV rays. It works by absorbing, reflecting or scattering sunlight, with SPF ratings indicating the level of protection against UVB rays.
• Types and Efficacy of Sunscreen: Various sunscreen types, including chemical, natural, spray-on, stick, aerosol, clear zinc, mineral and powder sunscreens, cater to different preferences and skin types, offering options from organic compounds that absorb UV rays to physical barriers that reflect them.
• Safe Sun Exposure with Wild Child Products: Wild Child offers a range of high-quality sunscreens suitable for all skin types, providing broad-spectrum protection with user-friendly formulations, emphasising the importance of using sunscreen effectively to ensure sun safety and skin health.

What Is Sunscreen?

Sunscreen is a topical product which can be applied to the skin to protect it against the harmful effects of the sun by either reflecting or absorbing UV radiation before it can inflict damage.

The dangers of sun exposure are well-documented and include premature ageing such as wrinkles and sun spots, sunburn and possible eye damage. However, the most significant risk of sun exposure is an increased risk of skin cancer. When UV radiation from the sun is allowed to penetrate the skin, it can lead to cellular damage and mutations that may contribute to skin cancer development over time. 

In addition to taking measures such as wearing protective clothing, a wide-brimmed hat and sunglasses and seeking shade throughout the day, sunscreen is considered to be one of the most valuable measures you can take to keep your skin safe and protected. 

When Was Sunscreen Invented?

While various forms of sunscreen have been used in different cultures for centuries, the sunscreen we know today is a relatively new invention that only became commercially available in 1932, when Australian chemist H.A. Milton Blake produced the first sunscreen containing the UV filter phenyl salicylate (salol). 

While Blake’s sunscreen was a major step forward in the right direction, it was introduced before the damaging effects of both UVA and UVB radiation were fully understood. For this reason, the sunscreen only provided a very minimal level of sun protection.

Since then, sunscreen formulations have advanced in leaps and bounds with contemporary sunscreen products now providing a far superior level of UV protection, while lasting longer and being more water resistant.

How Does Sunscreen Work?

The way a sunscreen works will depend on the individual product. Sunscreens are broadly categorised as either mineral (also known as physical or natural) or chemical sunscreens. Mineral and chemical sunscreens utilise various active ingredients which work in different ways to protect against UV radiation. 

The key differences between mineral and chemical sunscreens are:

• Mineral sunscreens utilise active ingredients (such as zinc oxide and titanium dioxide) to create a physical barrier on the skin’s surface to reflect and scatter UV radiation before it can penetrate deeper into the skin.
• Chemical sunscreens utilise active ingredients (such as octyl salicylate, octocrylene, homosalate or butyl methoxydibenzoylmethane) to absorb UV radiation and transform it into harmless heat.

It’s also important to note that sunscreens should be ‘broad spectrum’, which means they work to protect against both UVA and UVB radiation. 

UVA and UVB are both types of radiation emitted by the sun, however, they vary in their wavelengths and effects on the skin. While UVA rays penetrate deep into the skin (dermis) and primarily contribute to premature aging, UVB rays primarily affect the outer layer of the skin (epidermis). UVB rays are the main cause of sunburn and play a key role in the development of skin cancer.

Does Sunscreen Block Vitamin D?

Vitamin D is an important nutrient our bodies need for calcium absorption, good bone health, muscle function, immune system support, and cell growth and regulation. 

While there are numerous ways to obtain vitamin D from various food sources and supplements, exposing the skin to sunlight (specifically UVB rays) for around 10-15 minutes a couple of times per week is considered the most effective way to ensure you get enough vitamin D—but it does raise the question of how to get ample sun exposure without exposing yourself to undue risk?

While sunscreen provides protection against UVB rays, it doesn’t provide complete protection. Depending on the Sun Protection Factor (SPF) rating of the sunscreen, a small amount of UVB radiation is still able to penetrate the skin. 

The good news is that it only takes a small amount of sun exposure to trigger ample production of vitamin D, with numerous studies demonstrating that sunscreen use has minimal impact on vitamin D levels over time. For this reason, it is widely recommended that sunscreen be worn as a skin cancer protection measure irrespective of any effect it may have on vitamin D production.

Does Sunscreen Prevent Tanning?

If you were to wear sunscreen every day, apply it correctly and reapply as directed, in theory, your skin shouldn’t tan. However, it is still possible to tan when wearing sunscreen.

Tanning is a response to exposure to UV radiation which causes the increased production of melanin (a pigment that gives skin its colour). As mentioned previously, sunscreen doesn’t provide 100% protection against sun exposure. While sunscreens with a high SPF rating will provide good sun protection, prolonged exposure to the sun can still result in a tan.

Can Sunscreen Expire?

Like most consumer products, sunscreen does have a limited shelf-life. 

The Therapeutic Goods Administration (TGA) requires all sunscreen products sold in Australia to display an expiry date on the packaging, which you’ll usually find in an easily identifiable location such as on the crimp of the tube or on the bottom of the bottle. 

How Long Does Sunscreen Last?

While this can vary, most sunscreen products have a shelf life of around 2 to 3 years.

Does Expired Sunscreen Still Work?

Once a sunscreen has passed its expiry date, it should be discarded. Over time, the ingredients in sunscreen can separate. This may cause the active ingredients that provide UV protection to be applied inconsistently, compromising the effectiveness of the sunscreen.

What Does ‘SPF’ In Sunscreen Stand For?

SPF stands for Sun Protection Factor. The SPF rating of a sunscreen specifies the level of protection it provides against UV radiation and sunburn. 

In Australia, sunscreen products can have an SPF rating from as low as 4 up to a maximum rating of 50+. The higher the SPF rating, the greater the level of protection a sunscreen provides. For example, a sunscreen with a SPF30 rating would allow one-thirtieth (or 3.3%) of UV to reach your skin, while a sunscreen with a SPF50 rating would allow one-fiftieth (or 2%) of UV through.

Different Types Of Sunscreen – How Do They Work?

In today’s competitive market environment, consumers are spoilt for choice when it comes to choosing a sunscreen. From chemical vs natural sunscreens, to spray-on sunscreens, sunscreen sticks and clear zinc—but do they all work or are some sunscreens better than others? 

While every sunscreen product will provide UV protection in line with its specified SPF rating, there are a few differences between the various types of sunscreens.

Let’s take a look at the effectiveness of the various types of sunscreens.

Do Chemical Sunscreens Work?

Chemical sunscreens effectively absorb UV radiation and convert it into heat, providing protection against sunburn and UV-induced skin damage. They are lightweight and easy to apply, but some individuals may experience skin irritation or sensitivities due to certain chemical ingredients. Some chemical sunscreens may also require more frequent reapplication compared to mineral sunscreens for optimal effectiveness.

Do Mineral/Natural Sunscreens Work?

Natural sunscreens work by using mineral-based ingredients like zinc oxide or titanium dioxide to create a physical barrier on the skin that reflects and scatters UV radiation. They are effective at providing broad-spectrum protection and are less likely to cause skin irritation or allergies compared to chemical sunscreens. However, natural sunscreens can leave a visible white cast on the skin.

Do Spray-On or Aerosol Sunscreens Work?

Spray-on aerosol sunscreens are effective at providing UV protection when applied correctly. They use the same active ingredients as other sunscreen types to absorb or reflect UV radiation. However, aerosol sunscreens should be sprayed generously and rubbed in to ensure adequate coverage and protection. They may also be difficult to apply correctly in windy conditions.

Do Sunscreen Sticks Work?

Sunscreen sticks work effectively for targeted application on specific areas like the face, ears and around the eyes. They contain similar active ingredients as other sunscreen formulations and provide reliable UV protection when applied correctly. However, sunscreen sticks may be less practical for covering larger areas of skin and can feel waxy or thick on the skin.

Does Clear Zinc Sunscreen Work?

Clear zinc sunscreen works effectively by using micronized zinc oxide particles that are transparent on the skin. It provides broad-spectrum UV protection without leaving a white residue. Clear zinc sunscreen is suitable for those who want the benefits of zinc oxide without the visible white cast typical of traditional mineral sunscreens. 

Does Powder Sunscreen Work?

Powder sunscreen can be effective for touch-ups and providing additional UV protection over makeup. It uses mineral-based ingredients like zinc oxide or titanium dioxide to provide UV protection. Powder sunscreen is convenient for reapplication throughout the day but may not provide as consistent coverage as lotions or creams if used as the sole sunscreen. It may also be challenging to apply powder sunscreen evenly on larger areas of skin and they may not be as water-resistant as other sunscreen formulations.

Sunscreen With Wild Child

Wild Child is a leading Australian manufacturer of sunscreen products.

If you’re considering developing a sunscreen for your brand, we can offer a range of solutions to help you launch your new product in the shortest possible time. With extensive expertise in both chemical and mineral-based sunscreens, your products will be manufactured to the highest quality standards in our state of the art facilities using only TGA approved ingredients.

Find out more about sunscreen manufacturing with Wild Child or contact us to get started.