I read in the newspaper about SPF50+ sunscreens coming to Australian markets. Should we throw away our SPF30 products and stock up on SPF50+ sunscreen for increased protection in the sun?"

As of November 2012, Australian sunscreen manufacturers are allowed to make and advertise SPF50+ sunscreens. Despite the introduction of these new products with a higher SPF rating, there is no need to get rid of your current SPF30 sunscreens, providing they are broad spectrum, water-resistant and not passed their expiry date. 

The SPF rating indicates the amount of UVB radiation that potentially reaches the skin if the sunscreen is applied according to directions. For example, SPF30 is estimated to filter 96.7% of UVB radiation with 1/30th (3.3%) of UV reaching the skin. SPF50 is estimated to filter 98% of UVB radiation with 1/50th (2%) reaching the skin. Both can provide excellent protection if they are applied properly.

Sunscreen is an important sun protection measure, but should not be used as the first or only line of defence against ultraviolet radiation. Always re-apply sunscreen every two hours and use in conjunction with other sun protection measures: limiting time outdoors during peak UV times, using shade and wearing protective clothing, hats and sunglasses.