Sunscreen test results

What difference does the SPF make?

"SPF" stands for "sun protection factor". It's a measure of protection against mainly UVB rays, the ones that cause sunburn. The higher the SPF number, the greater the protection - up to 50+.

Above SPF 50+ the additional protection is very small. In fact, high SPF values are a problem. Studies have shown that people use them to stay out longer in the sun, using sunburn as a warning to take cover. During this time you can receive large doses of UVA radiation.

The Australian/New Zealand standard limits SPF claims to 50+ in line with other international standards.

For more information, see “What do the SPF numbers mean?”

What do the SPF numbers mean?

An SPF15 sunscreen that's properly applied is meant to give you 15 times the protection you'd get with unprotected skin. So if you were outside in the sort of sun that burns unprotected skin in 10 minutes, then SPF15 would give you 150 minutes of protection. For SPF30 sunscreen, that time would extend out to 300 minutes and for SPF50 it would be 500 minutes (see our Graph).

That’s the theory. These times will vary from person to person because of skin type, activities (such as heavy exercise or swimming) and how well the sunscreen is applied. No matter how high the SPF, any sunscreen should be reapplied regularly – every two hours you’re in the sun.

No sunscreen blocks 100 percent of UV rays: SPF15 blocks 93 percent of UVB, SPF30 blocks 97 percent, and SPF50 blocks 98 percent.

What does "broad spectrum" mean?

Broad spectrum sunscreens protect against UVA and UVB radiation. Both contribute to premature skin ageing, damage to the immune system and skin cancer.

UVA radiation penetrates deep into the skin layer; it's dangerous because there's no immediate warning sign (such as the sunburn caused by UVB rays).

Will the sunscreen protect me all day?

No - sunscreen can be sweated, washed or rubbed off, the chemicals may break down over time, and people simply don't apply enough. You should reapply sunscreen every 2 hours.

Does having a tan mean you don't need as much sunscreen?

No. A tan is a sign that skin damage has already started. Any further UV radiation will only add to the damage, resulting in wrinkled leathery skin and possibly skin cancer later in life.

Do I need a special sunscreen for my child?

Proper protection from the sun is more important during childhood than at any other time in life. Childhood and teenage sunburn is a high-risk factor for developing melanoma.

Sunscreens that are specially formulated for children have a mild base designed especially for their sensitive skin. But there's no reason why children shouldn't use the family sunscreen, provided it doesn't irritate their skin. Test a small amount on the inside of their forearm first.

According to Professor Marius Rademaker, from the Dermatology Unit at the Waikato District Health Board, you don’t need a special sunscreen for kids. He told us there was little evidence to suggest there was a safety issue with using the active ingredients of adult sunscreens on children.

Professor Rademaker told us it was important to remember that sunscreens were just one component of keeping safe in the sun. “As well as wearing sunscreen, children should wear protective clothing and sunglasses, and parents should plan outdoor activities for early in the morning or later in the afternoon.”

Keep babies and toddlers out of the sun as much as possible. The best protection for them is staying in the shade and using cover-up clothing - as it is for everybody.

What about irritation?

Certain ingredients in sunscreens can irritate some people. This may be due to sensitive skin or a reaction to one of the ingredients (a chemical, preservative or fragrance).

The active ingredients in sunscreens must be listed on the label. However, unlike other cosmetics, sunscreens are exempt from having to list all ingredients if they comply with the Australian requirements.

You can check the active ingredients and preservatives of our tested sunscreen here.

What are the active ingredients?

Sunscreen active ingredients can be divided into two groups – physical blockers and chemical absorbers.

Physical blockers (zinc oxide and titanium dioxide) work by reflecting or scattering UV radiation and are effective at protecting against both UVA and UVB radiation. A downside is they leave white marks on the skin, although some products now use nanoparticles – tiny molecules with one or more dimension less than 100 nanometres (nm) – which makes the sunscreen transparent.

Chemical absorbers (such as octinoxate or oxybenzone) work by absorbing UV radiation and can be further differentiated by the type of radiation they absorb – UVA or UVB. These sunscreens often have a combination of ingredients to protect against UVA and UVB.

Some people choose to avoid sunscreens with chemical absorbers because of potential health risks. In 2019, a study by US Food and Drug Administration (FDA) researchers found four chemicals (avobenzone, oxybenzone, octocrylene and ecamsule) may be absorbed through the skin at levels higher than previously believed.

In January 2020, a follow-up study by the same researchers on six sunscreen ingredients (avobenzone, oxybenzone, octocrylene, homosalate, octisalate and octinoxate), backed up these findings.

The FDA has asked the sunscreen industry to provide additional safety information on 12 chemical sunscreen ingredients to validate their safety and effectiveness.

The European Commission is also investigating whether some sunscreen chemicals have endocrine-disrupting properties. Last year, the commission asked for scientific data on 14 chemicals including homosalate and octocrylene.

Some ingredients, in particular oxybenzone (also called benzophenone-3) and octinoxate (aka octyl methoxycinnamate) are also emerging as an environmental concern, especially in beach regions where they get washed off.

Due to the evidence showing these ingredients adversely affect marine life, the New Zealand Dermatological Society recommends using sunscreens without them. From 2021, sunscreens containing oxybenzone and octinoxate will be banned in Hawaii, except on prescription. The Republic of Palau has also banned these ingredients, as well as additional sunscreen chemicals.

To choose sunscreens without these chemicals, check the packaging – all active ingredients in sunscreens must be listed.

Are nanoparticles safe?

There is debate about the safety of nanoparticles and whether they can penetrate the outer layer of skin (which has been shown in lab studies) and damage living cells.

In 2017, the Australian Therapeutic Goods Administration concluded the majority of studies found nanoparticles didn’t penetrate “or minimally penetrated” the skin, suggesting “systemic absorption, hence toxicity, is highly unlikely”.

The European Commission (EC) concluded available evidence suggests zinc oxide and titanium dioxide nanoparticles can be considered safe for use on the skin as sunscreens up to a concentration of 25 percent. This does not apply to sprayable products, which might be inhaled.

With cosmetic products, which include sunscreens, nanoparticle ingredients are required to be labelled. The word “nano” must appear in brackets after the ingredient. However, if a sunscreen complies with Australian regulations, this isn’t required and products don’t need to declare the ingredients’ particle size.