Evidence is trending to show that several common sunscreen chemicals have toxic or adverse effects on human health.

Extensive research has shown that a number of UV filters frequently used in commercial sunscreens (e.g. 4-MBC, octyl methoxycinnamate (OMC), octyl-dimethyl-PABA) possess endocrine-disruptor activity, i.e. interfere with endogenous hormone action and production.

Endocrine disruptors have been implicated in the development of a number of diseases, including reproductive cancers, as well as the abnormal development of the male reproductive system.

In one study, the application of oxybezone, 4-MBC and oxtinoxate for one week led to a drop in testosterone and oestradiol levels in men. More worrying is that these chemicals have been found in breast milk at concentrations known to have estrogenic effects.

A study by the Centre for Disease Control in the US found that 97% of the 2500 children and adults tested had oxybenzone in their urine.

Added to this is the problem that a large proportion of active ingredients in sunscreens can act as penetration enhancers to accelerate chemical absorption. Not good...

A recent move has been to nano-sized particles of titanium dioxide and zinc oxide to avoid the white paste residue. However, these ultra-fine particles may increase the risk of forming hydroxyl radicals ultimately damaging DNA.

We need to seek out safer alternatives, and look for sunscreens that resemble a food item rather than a complex toxic chemical equation.