Homemade sunscreen on TikTok? Give me all the chemicals

1:06 pm today
Woman applying sunscreen.

Experts are warning consumers against making sunscreen at home. Photo: Unsplash

Earlier this month, TikTok influencer Nara Smith kicked off a sunscreen controversy when she posted a video of her husband, Lucky Blue Smith, mixing up homemade sunscreen.

A bit of coconut oil, a bit of beeswax, a bit of zinc oxide, bit of this and bit of that is all you need for an effective sunscreen, right?

Nara Smith with her husband, Lucky Blue Smith, mixing up homemade sunscreen.

TikTok influencer Nara Smith in a video with her husband, Lucky Blue Smith, making sunscreen. Photo: TikTok

The video, which went viral across social media, piggybacks off a trend towards organic food, clothing and ingredients in our skincare and cleaning products. Smith is known for her almost-hypnotic cooking videos.

However, dermatologists in the US, where Smith is based, issued a warning against using homemade sunscreen, advising that it can lead to sunburn, premature aging and skin cancer. That advice is even more crucial for New Zealanders where peak UV levels can be 40 percent higher than at similar latitudes in North America.

Besides New Zealand's diminished ozone layer in the atmosphere, a primary UV ray defence, "the sun is literally closer to the Earth in the New Zealand summer, whereas it's further away from the Earth in the Northern Hemisphere," said Dr Louise Reiche, president of the New Zealand Dermatalogical Society. "We also have less pollution and we have an outdoor lifestyle."

Dr Louise Reiche

Dr Louise Reiche, president of the New Zealand Dermatalogical Society. Photo: supplied

Over the years, Reiche has seen the results of homemade sunscreens and it isn't good. Some patients have such severe sunburn the skin takes more than six months to recover. Others were left with permanent freckling.

I dabbled on the fringes of acceptable sunscreen when I lived in the US for a decade. When I started leaning towards using non-toxic products, I tried singular botanical ingredients like coconut oil rumoured to have an SPF rating of around four. I swapped out traditional sunscreens that use chemicals as active ingredients for mineral sunscreens that rely on zinc oxide and titanium dioxide.

In the US, where pollution and an ozone layer abound, mineral sunscreens seemed to work good enough. That has not been my experience in New Zealand when I moved here four years ago.

I quickly gave up the idea that a smattering of coconut oil could offer meaningful protection. I cycled through several mineral sunscreen brands from New Zealand, Australia and the US but always ended up with a red nose, cheeks and shoulders after swimming, sweating or just walking down the street. Now, I've gone back to using only chemical-based sunscreen.

Not all sunscreens are the same, and Reiche recommends using chemical sunscreen along with mineral components to protect again New Zealand's harsh sun.

"Zinc oxide is pretty good at protecting UVA [rays] but the UVB is much stronger here," said Reiche, of mineral sunscreens. "But if you're reapplying it, it should still be effective."

Belinda Castles from Consumer NZ.

Belinda Castles from Consumer NZ. Photo: D&K Photos Phil Scott

Belinda Castles, a research and test writer at the watchdog organisation Consumer NZ, sends her kids out into the sun for a day of lifeguarding with chemical-based sunscreen. They use a zinc oxide stick for extra coverage on vulnerable areas like nose, cheeks and lips.

New Zealand's sunscreen has come under tighter regulation since 2022. Sunscreens sold in New Zealand, whether chemcial or mineral-based, must be now independently tested to meet a set standard. Previously, Consumer NZ tested many sunscreens and created an annual guide for New Zealanders on effective sunscreens. The organisation found many didn't match the SPF claims stated on their packaging.

"When we tested them ourselves in a lab, which is an expensive exercise, we found sunscreens that only had an SPF of four or, you know ten," said Castles, "but [the makers] really didn't know that themselves because they hadn't tested it."

"It's not just as simple as mixing a few ingredients together with some zinc oxide," she added.

Now, Consumer NZ has a database of sunscreens that have been recently tested to show products meet the new legal standard.

Whatever sunscreen you use - provided it meets the standards laid out in the Sunscreen (Product Safety Standard) Act - should be applied before you go out into the sun and at regular intervals while using sun protection clothing, a hat and sunglasses, said Castles.

"We have really harsh UV rays here so it's a combination of all those sun safety measures," she said.

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