A group of chemicals in the body that helps to control a wide variety of chemical reactions is called?

The last safety review for oxybenzone was done in the 1970s, and does not reflect a wealth of information developed since that time indicating increased toxicity concerns and widespread human exposure. A recent review in the European Union found that sufficient data were not available to assess if oxybenzone in sunscreen was safe for consumers. Environmental Working Group again calls on FDA to review the safety of oxybenzone, given this new data on widespread contamination of the U.S. population, and to finalize its sunscreen safety standards so that consumers can be certain that sunscreen products they purchase are safe and effective.

Top scientists from CDC published results March 21, 2008 from a national survey of 2,500 Americans, age 6 and up, showing that oxybenzone readily absorbs into the body and is present in 97% of Americans tested (Calafat 2008). Oxybenzone, also known as benzophenone-3, was detected in the urine of nearly every study participant. Typically, women and girls had higher levels of oxybenzone in their bodies than men and boys, likely a result of differences in use of body care products including sunscreens.

A companion study released a day earlier revealed that mothers with high levels of oxybenzone in their bodies were more likely to give birth to underweight baby girls (Wolff 2008). Low birth weight is a critical risk factor linked to coronary heart disease, hypertension, type 2 diabetes, and other diseases in adulthood (Lau 2004). Among common sunscreen chemicals, oxybenzone is most likely to be associated with allergic reactions triggered by sun exposure.

In a study of 82 patients with photoallergic contact dermatitis, over one quarter showed photoallergic reactions to oxybenzone (Rodriguez 2006); another study reported 1 in 5 allergic reactions to photopatch tests resulted from exposure to oxybenzone (Bryden 2006). Sunlight also causes oxybenzone to form free radical chemicals that may be linked to cell damage, according to 2 of 3 studies (Allen 1996; Serpone 2002; Hanson 2006). A less visible but more alarming concern, this chemical absorbs through the skin in significant amounts, as indicated by the CDC study.

A previous biomonitoring study reported that 96% of 6 to 8 year old girls had detectable amounts of oxybenzone in their urine (Wolff 2007). An earlier study detected oxybenzone in the urine of all 30 adult participants (Ye 2005). Studies on human volunteers indicate a wide variation in the level of oxybenzone absorbed into the body, with some individuals absorbing at least 9% of the applied dose, as measured in excretions in urine (Hayden 1997; Janjua 2004; Sarveiya 2004; Gonzalez 2006).

Volunteers continued to excrete oxybenzone many days after the last application of the chemical, an indication of its tendency to accumulate in fatty tissues in the body (Gonzalez 2006). In addition to its ability to absorb into the body, oxybenzone is also a penetration enhancer, a chemical that helps other chemicals penetrate the skin (Pont 2004). Studies on cells and laboratory animals indicate that oxybenzone and its metabolites, the chemicals the body makes from oxybenzone in an attempt to detoxify and excrete it, may disrupt the hormone system.

Under study conditions, oxybenzone and its metabolites cause weak estrogenic (Nakagawa 2002; Schlumpf 2001, 2004; Kunz 2006; van Liempd 2007) and anti-androgenic (Ma 2003) effects. Oxybenzone displays additive hormonal effects when tested with other sunscreen chemicals (Heneweer 2005). Laboratory study also suggests that oxybenzone may affect the adrenal hormone system (Ziolkowska 2006).

One human study coapplying 3 sunscreen active ingredients (oxybenzone, 4-MBC, and octinoxate) suggested a minor, intermittent, but statistically significant drop in testosterone levels in men during a one-week application period (Janjua 2004).