Wearing sunscreen regularly is an essential part of protecting your skin from harmful sun exposure. But with so many choices available these days, it’s important to understand what goes into the different types of sunscreens and how these ingredients work to protect your skin. Here, we describe the key differences between mineral sunscreen and chemical sunscreen to help you make the right decision for your skin.
The sun causes damage to your skin when radiation from the ultraviolet (UV) end of the light spectrum penetrates the skin. UV radiation is divided into UVA and UVB radiation based on the wavelength of the light. UVB radiation is responsible for visible skin damage on the surface – that’s the sunburn we see so often at the beach. UVA radiation penetrates into the deeper layers of your skin, causing cellular damage linked to wrinkles and other signs of aging. Exposure to both UVA and UVB radiation can increase your risk of developing skin cancers.
Sunscreens protect your skin by preventing or reducing the amount of UV radiation from reaching the surface of your skin. They do this using active ingredients that act as UV filters and are classified into one of two groups; either chemical or mineral (also called physical).
Chemical UV filters protect the skin by actively absorbing and then dissipating the energy from UV radiation. While mineral UV filters also absorb energy from UV radiation, they have the additional effect of reflecting and scattering UV radiation when it reaches the skin.
Mineral sunscreen contains a mineral-based physical UV filter. The two common ingredients used for a mineral-based physical sunscreen are zinc oxide and titanium dioxide. These mineral UV filters work by forming a physical barrier on the surface of the skin that absorbs, reflects, and scatters UV radiation.
Forms a physical barrier on your skin. The outermost layer of your skin is called the stratum corneum and is composed of a protective barrier of dead skin cells called keratinocytes. Underneath the stratum corneum lies living skin cells in the remaining layers of the epidermis and the dermis. Because mineral sunscreen forms a physical barrier on the surface of your skin and very little of the mineral UV filter penetrates through the stratum corneum, they are less likely to be absorbed into living skin cells. This helps to lower the risk for skin irritation and makes mineral-based physical sunscreen a good option for sensitive skin and for babies over 6 months of age.
Provides broad spectrum protection. Sunscreens in New Zealand are required to have broad spectrum coverage that protects against both UVB and UVA radiation. Both zinc oxide and titanium dioxide offer effective protection against UVB and some UVA radiation, while zinc oxide also offers protection against the full spectrum of UVA radiation.
Less appealing texture or appearance on the skin. The light reflecting and scattering properties of mineral UV filters can result in sunscreen with a thick texture or that leaves a residual white film on skin. However, most mineral sunscreens now use formulations that contain micronised or nanoparticles of zinc oxide or titanium dioxide. This results in smaller mineral particle sizes, reducing the intensity of white film and improving both transparency, texture and consistency of the sunscreen.
Chemical sunscreen contains one or more chemical UV filters. There are almost 30 chemical UV filters approved for use in sunscreens in Australia. While all these chemical UV filters work by absorbing and stabilising UV radiation into the chemical molecule itself and then dissipating the energy as heat, they differ in which wavelength of UV radiation they absorb. Some chemical UV filters only absorb UVB, others only parts of the UVA spectrum, while others have been developed as broad spectrum UV filters that absorb radiation across both the UVB and full UVA range.
Provides broad spectrum protection. As previously mentioned, sunscreens in New Zealand must meet the standard of providing broad spectrum coverage. To achieve this standard, chemical sunscreens either use broad spectrum UV filters that absorb radiation across the UVB and UVA range, or they combine two or more chemical UV filters to deliver broad spectrum UV protection.
No white film. Chemical UV filters are usually free from the light reflecting properties that cause mineral sunscreen to sometimes leave a white film on the surface of the skin.
Always read the label. Follow the directions for use. When using sunscreen always wear a hat, protective clothing, and sunglasses. Avoid prolonged high-risk sun exposure. Reapply sunscreen frequently or use in accordance with directions.
Skin sensitivity. Chemical UV filters can penetrate the stratum corneum, meaning they can come into contact with living cells within the epidermis. Individuals with sensitive skin may have an increased risk of skin irritation or allergy.
Impact on marine environments. Certain chemical UV filters have been banned from use under the Hawaiian Reef Bill.
When you’re looking for a great sunscreen to protect your skin, explore the INVISIBLE ZINC range of mineral sunscreens. All INVISIBLE ZINC products contain micronised zinc oxide, using just the single mineral UV filter to offer broad spectrum coverage.
Mineral (physical) sunscreens contain the UV filters zinc oxide or titanium dioxide that form a physical barrier on your skin, absorbing and reflecting UV radiation. Chemical sunscreens contain one or more chemical UV filters to absorb UV radiation. Both will protect your skin from the sun.
Mineral sunscreen provides broad spectrum coverage against both UVB and UVA radiation by forming a protective layer on the surface of your skin.
To improve texture and transparency, mineral sunscreen often contains micronised or nanoparticles of zinc oxide or titanium dioxide. These mineral sunscreens form a protective layer on the surface of your skin to provide broad spectrum UVB and UVA coverage.