Good Sunscreen Practices: A Dermatologist’s Guide

Australia has a harsher climate than most countries. This, combined with the outdoor lifestyle of our culture, raises the risk of skin cancer. Protection from continuous Sun exposure is vital for reducing the risk of skin cancer, and for the prevention of premature ageing. Sunscreen plays a major role in this. But as not all sunscreens are alike, we must find and use sunscreen products that are both high quality and suitable for our skin type. To avoid confusion, the following guide explains how to select, apply, and benefit the most from sunscreen, according to your skin type.

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DermScreen was established in 2022 by a group of Australian dermatologists. Recognising the widespread problems with skin cancer in this country, we decided to improve melanoma survival rates through early detection. We do this through humanised technology, providing affordable, accessible, convenient skin screening in our three Sydney clinics. Visit us at Mosman, Bondi Junction, Randwick and Sydney CBD.

How to Choose the Right Sunscreen for Your Skin Type

Sunscreen selection should start with understanding your skin type.

Dry skin: Cream-based sunscreens with hydrating ingredients such as hyaluronic acid, glycerine, or ceramides help moisturise while providing UV protection.
Oily or acne-prone skin: Choose non-comedogenic, oil-free, or gel-based formulas that reduce shine and prevent clogged pores.
Sensitive skin: Mineral sunscreens containing zinc oxide or titanium dioxide are less likely to cause irritation. Fragrance-free and alcohol-free options are best.
Combination skin: A lightweight, balanced formula that hydrates dry areas without adding oil to the T-zone is recommended.

Understanding your skin’s needs ensures that sunscreen feels comfortable on the skin, encouraging consistent, daily use.

Chemical vs. Physical Sunscreen: What’s the Difference?

Sunscreens fall into two main categories: the chemical type and the physical type (mineral). There are also sunscreens that combine these types.

Chemical sunscreens use ingredients such as avobenzone, octocrylene, and oxybenzone to absorb UV rays and convert them into heat. These formulas blend easily and are cosmetically smooth. However, some ingredients may be absorbed into the bloodstream, and their long-term effects are still being studied. Some countries will ban some chemical sunscreens if they are known to harm marine life and coral reefs.
Physical sunscreens use zinc oxide or titanium dioxide. They sit on the surface of the skin and block or scatter UV rays. They are FDA-recognised as safe and effective and are ideal for sensitive skin, pregnancy, and children. Older physical sunscreens tended to leave a white surface on the skin, but newer formulas have improved significantly. Tinted sunscreens are almost unnoticeable if they match the tint of the skin.
Combination sunscreens use a mixture of chemical and physical filters. This both increases the SPF and improves the texture.

Is SPF 50 Really Better Than SPF 30?

SPF indicates how well a sunscreen protects against UVB radiation, the main cause of sunburn. Basically, the SPF number shows how long a person can stay exposed to the Sun and still suffer the same damage. An SPF of 30 means a person can stay in the Sun 30 minutes and only suffer 1 minute of sun damage.

SPF 30 blocks about 97% of UVB rays.
SPF 50 blocks about 98%.

While the difference seems small, SPF 50 is beneficial for people with fair skin, sensitive skin, or a history of skin cancer. Regardless of the number, the key is applying enough sunscreen and reapplying regularly.

Do I Need Sunscreen Every Day?

Yes. Sunscreen is necessary even on cloudy days, indoors, or during winter. Up to 80% of UV rays may pass through clouds, and UVA rays can penetrate window glass. Daily sunscreen use helps reduce the risk of skin cancer and will significantly reduce premature ageing.

Some people avoid sunscreen because they worry about vitamin D deficiency. There is a small measure of truth in this; limited sunlight exposure can lead to low vitamin D levels, affecting bone health and the risk of osteoporosis or rickets. However, sunscreen will not block all sunlight, and we can usually maintain healthy vitamin D levels through incidental sun exposure, dietary intake or perhaps supplements in more extreme cases. If you are worried, just make sure to get some Sun exposure in the early morning after sunrise. The sunlight is still quite moderate at this time. Early morning Sun exposure also helps reset your circadian clock so you can sleep at night.

How Much Sunscreen Should You Actually Apply?

Most adults apply only half of what they need for effective protection.

General guidelines include:

One ounce (a shot glass) for the entire body.
A teaspoon each for the face, neck, and each limb.
Apply 15–30 minutes before going outdoors, especially for chemical sunscreens.
Reapply every two hours, or sooner after swimming, sweating, or towel-drying.

Don’t forget commonly missed areas: ears, back of the neck, scalp, hands, and tops of the feet. Some people have learnt the hard way that sunburn on the back of the knees or elbows is very painful. This is easily avoided with sunscreen.

Common Sunscreen Mistakes and How to Avoid Them

Key mistakes include:

Using too little: Reducing protection by half.
Skipping reapplication: Especially at the beach or during outdoor activities. Reapply every 2 hours.
Using expired sunscreen: Never rely on products older than three years. Most sunscreen containers will include a use-by date. If in doubt, buy some new sunscreen.
Relying on makeup with SPF: Usually insufficient alone.
Not shaking the bottle: Ingredients can separate over time. If the product is too thick or too thin, then separation has occurred.
Do not skip sunscreen on cloudy days or for indoor time: UV rays still penetrate clouds and windows. Consider a SPF 30 for milder conditions, and a SPF 50 with protective clothing in high Summer.
Believing darker skin does not need sunscreen: While dark skin does help to a small extent, all skin tones can burn and develop skin cancer.

Best Sunscreen Practices for Children and Teenagers

Children and teenagers need reliable sun protection to reduce long-term risks.

Use broad-spectrum, water-resistant SPF 50+ sunscreen.
Apply 20 minutes before sun exposure and reapply every two hours.
A teaspoon of sunscreen is needed for each limb, the torso front and back, and the head/neck.
Combine sunscreen with hats, long sleeves, shade, and UV-protective sunglasses. If you buy the child/teenager a style of hat, glasses and shirt that they prefer then the items will get more use. Children and teenagers will wear the hat/glasses by choice rather than by obligation.
For infants under six months, avoid direct sunlight and rely on clothing and shade. Sunscreen should be used only on small-exposed areas if necessary. Children’s hats and an umbrella can be useful here.

Regular sun protection also helps prevent myopia progression in children, as spending time outdoors supports eye health.

Sunscreen for Sensitive Skin: Dermatologist Recommendations

Sensitive skin benefits most from:

Mineral sunscreens with zinc oxide or titanium dioxide.
Look for fragrance-free and alcohol-free formulas.
Your skin may benefit from soothing ingredients such as aloe vera, chamomile, or calendula.
It’s a good idea to patch test before first use. Allergies are rare, but a test is worthwhile.

Apply gently by patting rather than rubbing to prevent irritation, and re-apply consistently.

Other Forms of Sun Protection

Wearing a broad-brimmed hat goes a long way to protecting your face from Sun exposure. A suitable hat is inexpensive and should last a few years. Make sure to wash the hat on a regular basis to prevent moisture and fungal issues. Leaving the inside of the hat exposed to the Sun will remove most of these issues.

A decent pair of UV-proof sunglasses provide will solid protection for your eyes. Replace the Sunglasses every 2 years as the UV proof coating diminishes over time.

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A consistent sunscreen routine is one of the simplest and most effective ways to protect our skin. Finding the right product is not too difficult if we know our skin type. After this we just need to apply it correctly on a daily basis. It’s worth it to know that our skin is safe, and we reduce the ageing on our appearance.