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What's in that sunscreen

By Denise Elliot

Summer is just around the corner and that all important sunscreen needs to come out - although, not necessarily last year’s sunscreen sitting in the cupboard. It is definitely best to purchase new sunscreen for each season to maximise the protection, as the rated SPF of a product will drop over time.

From a beautiful skin perspective a SPF25 or 30 on the face will help our skin age better with less wrinkles and pigmentation - ideally applied all year round.

The higher the SPF level the higher the chemical ingredients - around a SPF of 25 or 30 will give you good cover without needing the extra chemicals of higher sun protection factor products - any product needs to be reapplied after excessive sweating or swimming. Plan your time around the sun. Find shade, wear a hat, sunglasses, light clothing and don’t get burnt.

Sunscreens are made in two ways - either using a mineral block, such as zinc oxide and/or titanium dioxide, or with chemical ingredients.

Chemical sunscreens deserve close scrutiny because most are known to permeate the skin to some degree. Laboratory studies of some sunscreen chemicals indicate that they may mimic hormones and may disrupt the body’s hormonal system. Two European studies have detected sunscreen chemicals in mother’s breast milk indicating that the developing foetus and newborn infants may be exposed to these substances (Schlumpf 2008, 2010).

Oxybenzone is an example of a chemical found in some sunscreens. It may act like oestrogen in the body and has been shown to alter sperm production in small animals. It also shows high rates of skin allergy. Octinoxate, sometimes called Octylmethoxycinnamate also shows hormone like activity and thyroid and behavioural alterations in animal studies.

Preliminary studies suggest a link between higher concentrations of oxybenzone and its metabolites in the body, and increased risk of endometriosis and lower birth weight in daughters (Kunisue 2012, Wolff 2008).

While the number of chemical ingredients in many of our daily skin products is ridiculously excessive, there is no doubt that melanoma is a horrific scenario, we do need to protect our skin from damaging UV rays. It is then our informed choice as to whether we choose a chemical or mineral sunblock. There has been no evidence of hormone disruption with mineral sunblocks.


Stands for Sun Protection Factor and is a guideline of how long you can stay in the sun without getting burnt compared to unprotected skin. To determine a sunscreen's SPF, the testing is conducted on human volunteers. The product is applied to small areas of the back which are then exposed to UV light for varying periods of time. The patches are evaluated the next day to identify the first area showing slight redness. This is used to calculate the SPF.