Understanding Sunscreen – Your Guide to Skin Protection

Sunscreen is not just a seasonal accessory; it is a daily necessity for protecting your skin from the harmful effects of UV radiation.

Australia has one of the highest rates of skin cancer in the world. Sunscreen use is one of the important ways of reducing the risk of skin cancer. The most comprehensive study of cancer prevention in Australia estimated that, in 2010, more than 1700 cases of melanoma and 14,190 squamous cell carcinomas were prevented by long-term sunscreen use.

What is Sunscreen and How Does it Work?

Sunscreen is a cream we can apply to our skin to protect our skins cell’s DNA from the Sun’s Rays. The suns UV rays can penetrate the skin and cause damage to the cell’s DNA. This cellular damage can result in skin cancer growth.

How good a sunscreen is at protecting you from UV radiation is measured by its sun protection factor or SPF. Sunscreen works by incorporating active ingredients that either absorb, reflect, or scatter UV radiation.

UVA vs UVB Rays

There are two types of UV radiation that impact the skin: UVA and UVB. UVA rays penetrate deep into the skin, causing long-term damage like wrinkles and age spots, however long term exposure to UVA rays can also cause skin cancer. UVB rays affect the surface, leading to sunburn and direct DNA damage which can result in skin cancer.

Sunscreens currently only have a UVB protection rating via the SPF system.

However, you need to protect your skin against both UVA and UVB rays as both are known to be harmful. To ensure you are getting this, a product should also contain a UVA screening ingredient such as – stabilised avobenzone, ecamsule, oxybenzone, titanium dioxide and zinc oxide. This will often be labelled on the packaging as Broad Spectrum or say UVA Protection. Currently there is no rating system for UVA protection.

Chemical vs Physical Sunscreens

The protective ingredients found in sunscreen are either chemical ie they form a film on the skin which absorbs UV light before it penetrates the sun, or physical, which reflect the UV rays away from the skin. Most sunscreens contain a mixture of both ingredients.

SPF Definition: Understanding Sun Protection Factor

SPF measures HOW LONG it will take for UVB rays to redden the skin when using the sunscreen, compared to how long it will take without sunscreen.

How long it protects you for will therefore be very different for each individual and could vary daily dependent on the sun’s intensity. For example, in some conditions it may take you 20 minutes to redden, whereas on another day it could take you only 10 minutes.

The number of the SPF gives you this time scale. For example, SPF 15 means it will take 15 times longer to redden your skin than it would take without sunscreen.

SPF 30 means it will take 30 times longer to redden your skin than it would without sunscreen.

Therefore, if it usually take you 10 minutes to go red without sunscreen, with SPF 15 it will take you 150 minutes to go red (15×10). So, reapply sunscreen at least every 150 minutes.

However if it takes your friend 5 minutes to go red without sunscreen, with SPF 15 it will now take 75 minutes to go red (15×5). Your friend will need to reapply the sunscreen more often than you.

An SPF 15 will screen 93% of the suns UVB, whilst an SPF 30 will screen against 97% and an SPF 50 will screen against 98%. For this reason, current recommendations are to use a broad spectrum SPF 30.

Different Types of Sunscreen

Choose a sunscreen that best suits your skin type and activity and that you find easy to reapply. If you have sensitive skin and have had a reaction to sunscreen in the past, look for fragrance-free products. If you don’t want sunscreen residue left on your hands, look for a gel.

Not all sunscreens contain the same ingredients. If your skin reacts to one sunscreen, talk to a chemist or doctor about choosing one with different ingredients.

Make sure the sunscreen is at least 30SPF, broad-spectrum and water resistant. Also check the expiry date of the sunscreen and the storage conditions recommended on the label. Most sunscreens last about two to three years and should be stored at a temperature below 30ºC.

Sunscreen for Different Skin Types

Choose the right sunscreen for your skin type is important ensuring optimal protection and comfort. Different skin types have unique needs, and selecting a sunscreen that caters to these can help prevent irritation, breakouts, or other skin issues.

Oily or Acne-Prone Skin

  • Non-Comedogenic: Look for sunscreens labelled as non-comedogenic, which means they won’t clog pores and cause breakouts.
  • Oil-Free and Lightweight: Formulas that are oil-free and have a matte finish can help control excess oil and shine.

Dry Skin

  • Hydrating Ingredients: Choose sunscreens with moisturizing components to help maintain skin hydration.
  • Cream-Based Formulas: These are often more hydrating than gels or sprays.

Sensitive Skin

  • Mineral Sunscreens: Physical blockers like zinc oxide and titanium dioxide are less likely to cause irritation.
  • Fragrance-Free and Hypoallergenic: Formulas without fragrances and common irritants are preferable.

Combination Skin

  • Balanced Formula: A sunscreen that hydrates dry areas without making oily areas greasy.
  • Lightweight and Non-Greasy: Gel-based or lightweight lotions often work well.

How Long Does a Sunscreen Last?

Sunscreen needs to be applied 20 minutes before going outside. Ensure you use a generous amount of sunscreen. When applying sunscreen, you need at least one teaspoon per limb, one for the front of the body, one for the back and one for the head. A full body application for an adult should be at least 35mL or seven teaspoons.

How Often Should You Reapply Sunscreen?

Sunscreen should be reapplied every two hours if you are spending time outside. As sunscreen can be easily wiped off, lost through perspiration you should also reapply after swimming, sweating or towel drying.

Don’t forget to reapply even if you’re wearing makeup or insect repellent.

The Importance of Regular Use

Including sunscreen into your daily routine is a simple yet powerful step you can take to protect your skin. Whether it’s a cloudy day or you’re spending most of your time indoors, UV radiation can still affect your skin, making daily application and reapplication crucial.

Common Myths and Misconceptions

There are many myths about sun protection. We are here to debunk them for you.

You can’t get sunburnt in the shade

Even though we can’t see or feel them, UV rays reflect off surfaces like sand, water and even grass. So, while a leafy tree or shade sail will block some UV rays, others will bounce from those sunny areas to reach your skin.

You can’t get sunburnt on cloudy or cool days

UV radiation can be just as fierce on a day when it’s hot and sunny, as when it’s cool or cloudy. Don’t forget that you can’t see or feel UV rays, so don’t let your senses fool you. Instead, check the sun protection times each day so you know when UV levels will be high enough to damage your skin. Or make it your routine to wear and reapply sunscreen every single day.

I have SPF in my makeup and moisturisers, I don’t need sunscreen

Makeup and moisturisers with SPF are great to add to your sun protection, but as with a regular sunscreen, you still need to top up your application every two hours.

Also be aware that most cosmetics offer protection that is much lower than the recommended minimum of SPF30 and may not be broad-spectrum to filter both UVA and UVB radiation.

I used to sunbake when I was younger, so it’s too late for me to bother with sunscreen

It’s never too late for skin cancer prevention and using sunscreen. In fact, skin cancer is one of the most preventable cancers because sun protection is effective at any age.

I won’t get skin cancer because I tan and don’t burn so I don’t need to wear sunscreen

All skin types can be damaged by UV radiation and all skin types can get skin cancer. That’s why we all need to use sun protection.
If your skin browns in the sun, it’s a sign UV rays have damaged your skin cells. A tan is a sign of skin cells in trauma, not health.

I need to increase my Vitamin D levels; I should go out in the sun without sunscreen

Research suggests that prolonged sun exposure does not cause vitamin D levels to continue to increase further but it does increase the risk of skin cancer.

When UV levels are 3 or above, most Australians get enough vitamin D with just a few minutes of sun exposure while completing everyday tasks – like walking to the car or shops. During peak UV times, it’s important to reduce your risk of skin cancer by protecting your skin.

If you believe you’re at risk of vitamin D deficiency, speak to your doctor.

I don’t need to wear sunscreen while driving if I have the window up

Untinted glass commonly used in car side windows reduces but does not completely block transmission of UV radiation.

This means you can still get burnt if you spend a long time exposed to an untinted side window when the UV is high.

FAQs About Sunscreen

Can sunscreen give you cancer?

There is no medical evidence that sunscreen causes cancer. There is a lot of medical evidence that UV rays from the sun and tanning beds do.

Can you still tan with sunscreen?

While we don’t encourage tanning via the sun, you can still tan while wearing sunscreen, but the process will be slower and less intense compared to tanning without any protection. While sunscreen significantly reduces the amount of UV radiation that reaches your skin, it does not block all of it. The remaining UV rays can still stimulate melanin production, leading to a tan over time.

Schedule a Skin Consultation

The MoS team recommend a number of sunscreens including RATIONALE #3 The Tinted Serum for daily use on the face, neck and decolletage. For the body we recommend Cancer Council sunscreens.

For personalised skincare advice, including sunscreens, book a consultation with our team here.

Book an appointment online or call the clinic on 5261 6171 to arrange an appointment.

Book an appointment online or call the clinic on 5261 6171 to arrange an appointment.

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