At least four types of sunscreen ingredients absorbed by the skin must be researched thoroughly, as a new report revealed they can enter the bloodstream at potentially dangerous levels.

A new study conducted by the Food and Drug Administration showed that a day is enough for four sunscreen chemicals to enter the bloodstream and remain there until the concentration of chemicals continues to increase with daily use.

Should sunscreen use be abandoned completely? Experts from the Center for Drug Evaluation and Research under the FDA said this does not mean that sunscreen use should be avoided. Instead, the FDA urges that more research must be done to ensure that these four sunscreen chemicals are "regarded as safe and effective."

Researchers Examine Sunscreen Ingredients

In the new study, researchers enrolled 24 healthy volunteers and randomly assigned whoever will use any of the following products: a spray or a lotion that contained the chemicals octocrylene, avobenzone, and oxybenzone, or a sunscreen that contained the chemical ecamsule.

Study participants were told to put on the sunscreen on 75 percent of their bodies four times each day for four days. Over the course of seven days, at least 30 blood samples were taken from each participant.

Researchers found that five out of six participants who used the sunscreen with ecamsule had traces of the chemical in their blood with levels that were significant enough by the end of the first day. Meanwhile, all the other participants who used the lotion or spray with three chemicals also showed significant levels in their blood.

Concerns Over Sunscreen Ingredients

Sunscreen was approved for use in the United States as a solution to sunburn. One type of sunscreen used chemicals to filter the sun, while another type of sunscreen used minerals such as zinc oxide or titanium oxide to block the sun.

David Andrews, a senior scientist from the Environmental Working Group, explained that there weren't a lot of concern about the impact of sunscreens at first, but this changed when the FDA began conducting safety tests.

Andrews explained the chemical oxybenzone stood out in the new study.

"Oxybenzone was absorbed into the body at about 50 to 100 times higher concentration than any of these other three chemicals they tested," Andrews added.

This can be alarming because a 2008 study examined urine samples and found traces of oxybenzone in 97 percent of the samples. Since then, oxybenzone has been linked to shorter pregnancies in women, hormone changes in men, and lower levels of testosterone in young boys.

However, these are only correlations, and researchers warn against concluding associations.

Still, some states have decided to ban the use of sunscreens with oxybenzone. In Hawaii, sunscreens that contained oxybenzone and octinoxate have been banned because they allegedly cause coral bleaching.

Sunscreen Is Not Unsafe, But More Research Must Be Done

Dr. Robert Califf, former chairman of the FDA, assured the public that the findings of the research, which has been issued in the journal JAMA, does not mean that sunscreen is unsafe.

On that note, Dr. David Leffell from the American Academy of Dermatology urged that more studies must be conducted to find out whether sunscreen has harmful effects. In the meantime, he said people should be "aggressive about sun protection."

Lastly, Scott Faber from the EWG said that finding out that chemicals put on the skin can be absorbed by the body is not new. He explained that the new study is the FDA's way of telling sunscreen manufacturers to conduct research to see if chemical absorption poses health risks.

Photo: Cam Fu | Flickr