Can food coloring poison you?
Dyes, pigments or colorings are found in soaps, shampoos, shaving creams, lipsticks, vitamins, cereals, juices and contact lenses—and that's even before your day gets going. The Food and Drug Administration subjects additives to the most rigorous tests of any products out there.

Over the years, certain dyes have raised red flags. One, FD&C Yellow No. 5, listed as tartrazine on some medicine labels and found in dessert powders, custards and some beverages, can cause itching and hives, though in fewer than one out of 10,000 people. Still, safety notwithstanding, the FDA suggests that consumers should avoid taking in huge quantities of any single additive.

Bottom line: Have one maraschino cherry, not 2,000.

Are warts contagious?
Yes. Warts are infections, caused by viruses, and thus transmissible. If your best friend has a wart, avoid using her towel or unlaundered clothes.

Bottom line: Friendship has its boundaries.

Can my cell phone give me brain cancer?
Cell phones are, essentially, two-way radios that emit low levels of radiofrequency (RF) energy both during stand-by mode and when you're using them. Scientists have found that exposure to RF over a prolonged period of time (22 hours a day in animal experimentation) can cause adverse health effects by heating up body tissue. As for humans? According to the FDA, "The available scientific evidence does not show any definitive health problems associated with using a cell phone." Then again, the FDA website also points out there's no proof that wireless phones are absolutely safe, either.

Bottom line: The jury's leaning heavily toward feeling safe, but it's still out. Our educated guess? Talk on.

Can cooking with aluminum pots and pans give you Alzheimer's?
No one knows the causes of Alzheimer's, and scientific studies associating aluminum with the disease are conflicting. The Alzheimer's Association website states, "The majority of mainstream scientists"—as well as the World Health Organization, the National Institutes of Health and the Environmental Protection Agency—"now believe that if aluminum plays any role at all in Alzheimer's, that role is small." People would have to ingest an almost comically inhuman amount of aluminum from cookware to come close to the levels reported to be found in Alzheimer's patients' brains.

Bottom line: The risk doesn't pan out.

Are aspartame and saccharin bad for you?
In response to a slew of cyber rumors that aspartame (NutraSweet, Equal) contributes to a variety of ailments, George Pauli, associate director for science and policy at the Office of Food Additive Safety for the FDA, says: "Aspartame...has been widely tested, and we've come up with no problems at all."

Saccharin is a slightly different story. Extensive tests have proven that high doses cause bladder cancer in rats, but the National Cancer Institute has determined that people who ingest saccharin show no greater risk of cancer than those who abstain from the stuff. But, Pauli adds, "It's a lot easier to do rigorous tests on rats than it is on people."

Bottom line: If terms like "unlikely" and "not a strong risk" don't soothe you, stay away from saccharin.

Do microwave ovens cause infertility?
The FDA's Center for Devices and Radiological Health, which regulates the manufacture of microwave ovens, says there is little cause for concern. Excessive leaking of microwaves is likely to occur only if the oven predates 1971 or if its door hinges, latch or seals are damaged. Even then, the amount of microwaves is negligible, unless your oven has been doubling as your pillow. A person standing roughly two feet away from a microwave oven would receive one 100th the amount of microwaves received at two inches.

Bottom line: "We are not aware of any health risks from microwave oven leakage," says an FDA spokesperson.

Can tooth-whitening wreck your teeth?
Before considering any tooth-whitening agent, says Christine Dumas, D.D.S., you'll want your dentist to see if any of your teeth are cracked, you have cavities, or your gums have receded, exposing roots (if you dab tooth-whitening paste onto a naked root, your loved ones will have to peel you off the ceiling). Also, if you have crowns or two-color fillings, you could end up with teeth of various shades—hardly that fresh-faced, surfer-girl look you had in mind.

Bottom line: For a completely safe whitening, let your dentist do it.