Wednesday, 25 April 2007



The quesion is what is worse - moderate sun exposure or sunscreen? - read on - do you want to put this on your skin?

Benzophenone and oxybenzone (benzophene 3) are chemicals used in many sunscreens. They are among the most powerful free radical generators known. Another chemical found in sunscreen, Octy Methoxycinnamate (OMC), may be dangerous if it gets into the bloodstream, according to researchers in Norway, after observing its effects on mice. Scientists from the Norwegian Radiation Protection Authority believe that human cells could be damaged if this chemical penetrates into the skin. As far back as the 1970s, Professor Howard Maibach discovered that as much as 35% of sunscreen does enter into the bloodstream and the longer it is on the skin the more is absorbed.

Triethanolamine (TEA) is a chemical found in many sunscreens. When applied topically to female mice, an increase in liver tumors was noted, whereas male mice had a smaller increase in liver tumors but also developed kidney tumors. TEA combined with water or nitrates (often used as a preservative but not required by law to be listed) can produce nitrosomines, which are carcinogenic.

In 1997 sunscreen chemicals such as benzophenone and ethylhexyl-p-methoxycinnimate, and PABA esters such as padimate-o and octyl dimethyl PABA were banned by the European community. Light reflecting substances such as titanium dioxide and zinc oxide were incorporated into sunscreen as well as avobenzone or Parsol 1789. The latter is a chemical which blocks UVA but is also a free radical generator and skin penetrant. In a study conducted at Queens University in Northern Ireland, scientists found that 2-phenylben zimidazole-5-sulfonic acid (PBSA), an ingredient found in some sunscreens, damaged DNA when exposed to light. It is not known if this happens in humans as this research has been done in test tubes thus far.



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