A new study published in JAMA suggests the FDA may have reason to look more closely at the ingredients that protect patients from sun damage. Try this question on the details.
Results of a randomized clinical trial titled "Effect of Sunscreen Application Under Maximal Use Conditions on Plasma Concentration of Sunscreen Active Ingredients" have prompted the FDA to invite industry and "other interested parties" to conduct formal, longer-term studies on systemic absorption of chemicals that block the sun's harmful UV rays.
Which of the following active sunscreen ingredients achieve human blood levels > 0.5 ng/mL?