SPF refers to the length of time you can be exposed to the sun before signs of sun exposure are visible (skin redness, etc). An SPF rating of 15 means you will receive the equivalent of one minute of sun exposure if you spend 15 minutes in the sun. However, SPF only refers to UVB unless it is SPF 50. UVB is responsible for skin burning whereas UVA is responsible for skin ageing.
An SPF below SPF 50 does not protect against UVA, which can travel deeper into the skin than UVB and cause damage over time without immediate visible signs of sun damage. UVA damage has been linked to fatal melanomas and skin cancers. Many people have a false sense of security when they use sunscreen with SPF 30 – they may not wear a hat and they may extend their sun exposure – meanwhile the UVA is freely damaging their skin.
When it comes to sunscreen, the guidelines are to apply sunscreen liberally – using about 30 grams for the whole body or a third of a teaspoon for the face – every two hours and at least 15 minutes before exposure. For more info, visit http://www.cancer.org.au/cancer- controlpolicy/ position-statements/sun-smart.
You must remember, however, that wearing sunscreen and a hat or sitting under the shade is not sufficient. For instance, you can still get sun damage sitting under shade next to a swimming pool because 70% of sun exposure is reflected; and UVA penetrates untinted glass so many people have more sun damage on one side of their face due to sun exposure while driving.
Look for Dr Serene’s Sunvisor for optimum eye protection and coverage against UVB and UVA.