Sad to say, Australia has the highest per-capita rate of skin cancer in the world, according to the World Cancer Research Fund International. So with summer just around the corner, there’s never been a better time to learn about sunscreen.

The first point to make is that using sunscreen can, literally, save your life.

A 2020 study by Gordon et al, which modelled the incidence of skin cancers in Queensland over the next 30 years, found that daily sunscreen use could prevent 1,055 melanomas and 16,977 keratinocyte skin cancers per 100,000 people.

With that in mind, let’s take a deep dive into sunscreen – and bust some myths along the way.

When should you use sunscreen?

The Cancer Council advises people to use sunscreen whenever the UV Index is forecast to be 3 or above.

“Sunscreen needs to be applied 20 minutes before going outdoors. 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,” according to the Cancer Council.

“Many Australians apply too little sunscreen and forget to reapply. Sunscreen should be reapplied every two hours if you are spending time outdoors. As sunscreen can be easily wiped off, lost through perspiration you should also reapply after swimming, sweating or towel drying.”

How important is SPF?

Sun protection factor (SPF) is very important, according to the Cancer Council.

“In laboratory conditions, when used as directed, SPF30 sunscreen filters 96.7% of UV radiation and SPF50 filters 98%. Both provide excellent protection if they are applied properly,” the Cancer Council says.

The highest SPF for sunscreen available in Australia is SPF50+.

Chemical vs mineral – which type of sunscreen is best?

There are two types of sunscreen – chemical and mineral (or physical), which refer to the active ingredients used.

The active ingredients in mineral sunscreens create a barrier on your skin that reflects UV light, according to the University of Texas MD Anderson Cancer Center – which makes them better.

“Mineral sunscreens offer the most protection because they’re literally creating a physical separation between you and the sun,” dermatologist Anisha Patel says.

However, mineral sunscreens can feel uncomfortable and can leave a chalky residue, so some people prefer chemical sunscreens, which are less obtrusive – but also less effective.

That’s because chemical sunscreens absorb UV rays and also wear off more quickly than mineral versions.

Here’s how to tell the difference when shopping:

Mineral sunscreens typically contain active ingredients like zinc oxide or titanium dioxide. In Australia, popular options include brands like Invisible Zinc, Blue Lizard and Surf Mud.

Chemical sunscreens usually include ingredients such as oxybenzone, avobenzone or octinoxate. Examples commonly available are the Cancer Council’s Ultra SPF 50+, La Roche-Posay Anthelios and Nivea Sun Protect & Moisture.

Spray vs stick vs lotion – which type of sunscreen is best?

The answer is lotion, according to Healthline.

Spray is the worst option. “Most of the sunscreen that exits the container doesn’t make contact with your skin because it gets scattered into the air from even light airflow or wind,” Healthline says.

Stick is better. “But it’s easy to miss a spot because many stick sunscreens are narrow and you have to do a lot more work to get full coverage. They’re convenient to use on your face or smaller exposed areas of skin, but they’re not recommended for use on your entire body if you want convenient, sufficient protection.”

Lotion is the best. “Lotion sunscreens typically provide the most coverage because they are easy to pour or squeeze out of a bottle and spread widely on your skin. It’s hard to miss a spot as long as you can reach that spot with your (or someone else’s) hand.”

Which brand of sunscreen should you buy?

The Cancer Council stocks a range of SPF50+ sunscreens, which you can buy online.

If you want more options, Vogue has curated “the 15 best dermatologist-recommended sunscreens in Australia”.

Are chemical sunscreens unsafe?

The Cancer Council says it’s a myth that chemical sunscreens are toxic.

“The Therapeutic Goods Administration (TGA) regulates sunscreens in Australia, ensuring that only approved ingredients, including chemicals, which have been assessed for quality and safety, are used in each product. Given there have been many rigorous scientific reviews, there is now very strong evidence that the list of commonly used active ingredients used in sunscreen do not pose a concern for human health.”

Does sunscreen become unsafe after the expiration date?

No. But the ingredients can break down over time, which can reduce the effectiveness of the sunscreen, according to Healthline.

Is there a difference between face and body sunscreen?

Not according to Healthline, which says you don’t need to separate sunscreen for your face.

“That said, your face is often more sensitive than the rest of your body, so many people prefer a lightweight, nongreasy sunscreen formulated specifically for the face, especially for everyday wear. These are less likely to clog pores, cause breakouts, or irritate skin.”

Can you suffer sun damage when the sun is not out?

Yes, says the Cancer Council, because sun damage is caused by UV radiation, not temperature. “In fact, UV radiation can penetrate clouds and can even be more intense due to reflection from them.”

Can you suffer sun damage if you have darker skin?

Yes again, according to the Cancer Council. “Regardless of skin type, exposure to UV radiation from the sun and other artificial sources, such as solariums, can cause permanent damage to the skin. People with skin types that are less likely to burn can still receive enough UV exposure to risk developing skin cancer.”

Last word

The Cancer Council says using sunscreen is just one of five important ways of reducing the risk of skin cancer. The others are:

  • Wearing sun-protective clothing that covers as much skin as possible
  • Wearing a hat that protects your face, head, neck and ears
  • Wearing sunglasses
  • Seeking shade

On a similar note, Dr Jennifer Lin of Harvard Medical School warns there’s a danger in assuming that putting on sunscreen is enough to protect you against the sun.

“Many studies have demonstrated that individuals who use sunscreen tend to stay out in the sun for a longer period of time, and thus may actually increase their risk of skin cancer,” she says.