Chances are you’ve seen the SPF rating on a bottle of sunscreen. You likely know what SPF is and why you need it to protect your skin from skin cancer. But do you know what UPF stands for and why it is also important?
The Difference Between SPF and UPF
Both SPF and UPF involve ratings, but they measure two different things. In a nutshell, SPF measures how effective a sunscreen is at protecting your skin against burning from the sun’s rays. UPF, on the other hand, measures the amount of UVR (ultraviolet radiation) that a fabric blocks.
The SPF (Sun Protection Factor) on Sunscreens
SPF is the measurement of how well a particular sunscreen protects your skin from sunburn.
To generate an SPF rating, researchers measure SPF in a laboratory on human skin. They measure it by identifying the amount of time it takes for skin to get burnt by ultraviolet radiation (particularly UVB, the culprit behind sunburn) in two ways: (1) without sunscreen, and (2) with sunscreen that’s been liberally applied.
If skin that has sunscreen protection burns in about 300 seconds, for example, but without sunscreen takes only 10 seconds, the SPF would be 300/10. This is equivalent to SPF30.
SPF only measures the amount of blocked UVB, not UVA. You can purchase sunscreens, known as broad-spectrum sunscreen, that protect you from both types of rays. The Cancer Council Australia recommends using a non-expired sunscreen labelled as SPF30 or above, water-resistant, and broad spectrum.
The UPF (Ultraviolet Protection Factor) on Clothing
Over the past 20 years, clothing with UPF has been seeing substantial growth worldwide, including here in Australia.
Sun protection clothing isn’t SPF rated, but rather UPF rated. The UPF rating measures how able the fabric is in blocking the sun’s ultraviolet radiation (UVR). Sun protection clothing is treated with chemical UV absorbers or colourless dyes that block out ultraviolet-A rays (UVA) and ultraviolet-B rays (UVB).
The current Australian / New Zealand Standard is broken down into three UPF ratings and protection categories as follows:
|UPF Rating||Percent UPV Block||Protection Strength|
|40, 45, 50, and 50 plus||over 97.5%||Excellent|
|25, 30, and 35||96.0–97.4%||Very good|
|15 and 20||93.3–95.9%||Good|
As the UPF number gets higher, your skin is exposed to less light. A 50 UPF rating would mean the fabric allows two percent or 1/50th of the sun’s ultraviolet radiation to get through and reach your skin.
Each fabric varies on the UPF ratings depending on the following:
- Colour: Darker colours absorb more light than lighter colours
- Material weight: Heavier fabrics absorb more UVR
- Weave: The tighter the weave, the less UVR can get through
- Moisture content: Some fabrics provide less protection when wet
- Tension or stretch: More fabric stretch reduces UPF rating
- Condition of fabric: Frayed or worn fabrics lets more UVR through
Light-coloured garments would provide you with less protection from UV rays and can even be as much as 50 percent less protective if wet.
More Skin Safety Tips and Tools
Wearing protective clothing and applying sunscreen are only two important things you can do to reduce your risk of skin cancer. You should also seek shade, slap on a wide-brimmed hat, slip on sunglasses, and get screened for skin cancer to decrease your skin cancer risks.
It’s vitally important that you get checked for skin cancer early on and that you know your risk level. You can find out right now if you have a high risk of melanoma by taking our MoleMap Risk Assessment Tool. And if it’s found out that you’re at risk, you can then begin taking the necessary preventative action steps.
MoleMap is one of the best screening tools for catching melanoma early. In fact, it can and has diagnosed almost ten times more early-stage skin cancer cases than any other screening tool or practice. MoleMap offers you an almost 100% five-year survival rate.
Early detection is vital. Tumours that are thin and haven’t yet travelled down from the surface of your skin most likely mean they haven’t spread into the layers or other parts or areas of your body, which could be fatal.
When you use MoleMap to detect melanoma early, you provide yourself with a higher likelihood of being able to have it cut out and cured.