Understand what to look for when choosing a sunscreen, including Sun Protection Factor (SPF), broad spectrum and an AUST L number.
The sun is the strongest source of ultraviolet radiation (UVR). The UVR spectrum includes ultraviolet A (UVA) and ultraviolet B (UVB). Of the UVR that meets the Earth’s surface, approximately:
Both UVA and UVB can cause skin cancer. UVA is responsible for skin tanning and skin aging. UVB is the primary cause of sunburn.
The SPF measures how effectively a sunscreen protects the skin from UVB radiation, which causes sunburn. The SPF rating must be clearly displayed on the label.
To protect your skin from damage, choose a sunscreen with SPF 30 or higher.
When used correctly, a SPF 30 sunscreen filters out around 97% of UVB rays, while a SPF 50 sunscreen filters around 98%. The difference in protection between a SPF 30 and SPF 50 sunscreen is small. The difference becomes smaller as the SPF value increases. Even a SPF 25 sunscreen still filters around 96% of UVB rays and provides much better protection than no sunscreen at all.
Regardless of the SPF value, you should always apply sunscreen according to the instructions on the label and reapply frequently. Most people do not use enough sunscreen.
SPF has usually been measured on human skin in a laboratory. Scientists measure how long it takes for intense UVB radiation to burn skin with the sunscreen liberally applied compared to bare skin. For example, if skin protected with a sunscreen takes 300 seconds to burn, but bare skin burns in 10 seconds, the sunscreen’s SPF is 30 (300 divided by 10). Right now, all sunscreens in the ARTG need to be tested in this way.
In 2025, a new way of measuring SPF was developed by the International Organization for Standardization (ISO). The new way involves testing sunscreen in a laboratory. We are currently reviewing existing SPF testing requirements, including exploring using this test method.
Find out more about our SPF testing review.
The term ‘broad spectrum’ on a sunscreen label means that the sunscreen provides protection against both UVA and UVB radiation.
All sunscreens used primarily for UV protection must provide broad spectrum protection and this must be clearly displayed on the label.
Mineral sunscreens (also called physical sunscreens) use zinc oxide and/or titanium dioxide as their active ingredients to protect the skin by reflecting or scattering UV rays.
Chemical sunscreens absorb UV rays and convert them into heat energy, which is then released from the skin.
Both mineral and chemical sunscreens protect against UVR and offer advantages and disadvantages. For example, mineral sunscreens can be gentler on the skin, but can feel thicker and heavier. While chemical sunscreens are generally more lightweight and non-greasy.
It's best to choose the product that you prefer as you are likely to use it more frequently.
All sunscreens we regulate must be included in the ARTG and display an AUST number on the front product label. You can read more about how we regulate sunscreens.
You can use the product’s AUST number to search for the sunscreen on our publicly accessible ARTG database. The ARTG entry for the medicine includes information such as the ingredients included in the sunscreen. The name of the product in the ARTG for the AUST L number must be the same name that is on the product’s label.
