Sunscreen 101: Natural vs Synthetic - What to Know for Skin Health in Aotearoa

New Zealand experiences some of the highest levels of UV radiation in the world. This is largely due to our relatively clear skies, outdoor lifestyle, reflective surfaces such as water and sand, and historically reduced stratospheric ozone at our latitude. As a result, daily sunscreen use is recommended year round, not just in summer, to help reduce the risk of sunburn, photoageing, and skin cancers including melanoma. Choosing the right sunscreen for your skin type and lifestyle genuinely matters.

One of the key decisions is whether to use a mineral (often called natural) or synthetic (chemical) sunscreen. Both can offer effective UV protection, but they differ in how they work, how they feel on the skin, and their broader environmental considerations. At Zurma, we generally encourage mineral sunscreens where suitable, due to their strong safety profile for sensitive skin and their more favourable environmental characteristics.

Mineral (Natural) Sunscreens

Mineral sunscreens use physical UV filters, most commonly zinc oxide or titanium dioxide. These sit on the surface of the skin and protect by reflecting, scattering, and absorbing UV radiation.

Why choose mineral sunscreens?

Generally well tolerated by sensitive, reactive, or compromised skin

Provide broad spectrum protection when formulated correctly, particularly with zinc oxide

Begin protecting immediately after application

Less likely to sting the eyes

Zinc oxide is considered low toxicity to marine life compared with many organic UV filters

Things to be aware of:

May leave a visible white cast, although newer formulations have improved significantly

Thicker textures can take more care to apply evenly

Like all sunscreens, they still require regular reapplication, especially with sweating or swimming

Synthetic (Chemical) Sunscreens

Synthetic sunscreens work by absorbing UV radiation and converting it into a small amount of heat. Common filters include avobenzone, octocrylene, oxybenzone, and octinoxate.

Why some people choose them:

Lightweight, transparent feel on the skin

Often easier to spread and cosmetically elegant

Frequently formulated with high water resistance, making them popular for sport and prolonged outdoor activity

Important considerations:

More likely to cause stinging or irritation for some people, particularly around the eyes

Certain filters, such as avobenzone, are photounstable unless carefully stabilised

Oxybenzone and octinoxate have been shown to contribute to coral reef damage in laboratory and field studies, and their use is restricted or banned in places such as Hawai‘i and Palau

Some synthetic UV filters have demonstrated endocrine disrupting effects in animal and in vitro studies, meaning they can interfere with hormone signalling under certain conditions

Human absorption of several chemical UV filters through the skin has been confirmed under maximal use conditions, although the long term clinical significance of this exposure is still being evaluated

Why sunscreen matters so much in Aotearoa

In New Zealand, unprotected skin can begin to burn in as little as 10 to 15 minutes on a clear summer day. UV exposure also occurs on cloudy days and through glass, particularly UVA radiation. The Cancer Society of New Zealand recommends the daily use of a broad spectrum SPF 30 or higher sunscreen, especially during the months of daylight saving.

General guidance:

For daily use, non nano zinc oxide based sunscreens are a good option for many people due to their broad spectrum coverage and skin compatibility

For tamariki, pregnant people, and those with sensitive or compromised skin, mineral sunscreens are often the preferred choice

For extended outdoor work or beach days, some people may choose a chemical sunscreen for its feel or water resistance. If so, opting for formulas without oxybenzone or octinoxate and reapplying regularly is sensible

What to look for in a sunscreen

Broad spectrum protection against both UVA and UVB

SPF 30 or higher

Zinc oxide based formulas for sensitive or eco conscious use

Free from oxybenzone and octinoxate where possible

Water resistance suited to your activity level

Sunscreen do’s and don’ts

Apply synthetic sunscreens around 20 minutes before sun exposure

Mineral sunscreens work immediately after application

Reapply every two hours, and after swimming or heavy sweating

Do not rely on SPF in makeup or moisturiser alone

Do not skip sunscreen on cooler or overcast days

Use sunscreen alongside shade, protective clothing, and hats for best protection

In summary

All approved sunscreens provide protection when used correctly, but they are not all the same. Mineral sunscreens, particularly those based on zinc oxide, offer a reliable, well tolerated option for many people and align well with both skin health and environmental considerations. In Aotearoa, where UV levels are especially high, thoughtful sunscreen choices play a key role in protecting both our skin and the taiao.

References
Matta, M. K., Zusterzeel, R., Pilli, N. R., et al. (2019). Effect of sunscreen application under maximal use conditions on plasma concentration of sunscreen active ingredients: A randomized clinical trial. JAMA, 321(21), 2082–2091.
Krause, M., Klit, A., Jensen, M. B., et al. (2012). Sunscreens: Are they beneficial for health? An overview of endocrine disrupting properties of UV filters. International Journal of Andrology, 35(3), 424–436.