"The funding agencies that we've submitted to have said that this is something that industry should fund, but industry has cut [budgets for] research and development," explains Kerry Hanson, a chemist and sunscreen researcher at the University of California at Riverside. As a result, so-called "safe" sunscreen ingredients may simply be the ones that haven't been as thoroughly researched.
The one thing that is clear is that any sunscreen is far better than no sunscreen_ sunburns, especially in children, are much more dangerous than a little oxybenzone or retinyl palmitate. That said, don't rely on sunscreen to do all the work. If your family spends lots of time outside, invest in sun hats and sun-protective clothes, which pose no known risks except maybe to your bank account.