Sunscreen and insect repellent in the same bottle? The products may save time, but the government is questioning if there should be more oversight.

The issue: A handful of small studies, using animal and human skin cells, suggest mixing sunscreen with the insect repellent DEET might increase DEET absorption — and make sunscreen not protect as well.

Also, sunscreen is supposed to be applied repeatedly in great dollops, as sweating or swimming wears it off. And it's for young children, starting at 6 months of age. But insect repellents have limits on how often they're used, and how young. How can product labels reconcile those instructions?

About 20 versions of sunscreen-bug repellent combinations are sold, says the Food and Drug Administration. The FDA regulates sunscreen, and the Environmental Protection Agency regulates insect repellent — but the combo products are in limbo, not really belonging to either agency.

So the FDA put out a notice seeking comment on whether concerns were strong enough that the products should have additional oversight.

No, says the Cosmetic, Toiletry and Fragrance Association, which contends the studies that raised the questions are flawed.

"We need to do more studies," counters Dr. Darrell Rigel of the American Academy of Dermatology.

Complicating the issue, Canadian researchers recently tested human skin cells and found questions beyond all-in-one products: Spraying on DEET and then rubbing on sunscreen actually increased DEET absorption the most.

Just because more DEET is absorbed doesn't mean it's enough to harm, cautions Dr. Charles Ganley, FDA's nonprescription drugs chief. His bigger question is whether the products bear proper instructions.

A decision could come later this year.