The Five-second Rule: It’s Actually True, Sometimes

Susan Patterson

12 years ago

Q: My mom (Grandma) is always picking up my baby’s pacifier off the floor and saying, “Five-second rule – it’s OK.” It freaks me out. Is it safe? – Paula P., Atlanta

A: Is there any science behind many moms’ favorite germ-control method – the five-second rule? Millions of parents, grandparents and legions of parenting gurus and doctors say there is. But we thought we might take a closer look, and you’ll be surprised by what we found.

Even though you want to make sure your children’s immune system develops properly (they need exposure to good and bad bacteria for that), too much of the five-second rule isn’t healthy. It depends on what hit the ground (wet things like apple slices and pacifiers collect germs quickly; harder, dryer candies or crackers, not so much) and where it landed (the sidewalk is surprisingly clean, say researchers, while your kitchen floor may have bacteria from raw meat juices and other foods that can cause gastro-upset).

If nasty bacteria are lurking underfoot, it takes ingesting about 10,000 of them to get sick. Any fewer and the body usually fights them off rather easily. So, how soon can those 10,000 glom on to a dropped pacifier? In a flash – whether it’s been 1 second or 30 – it’s covered with bacteria. Picking it up and giving it a quick rinse under running water may reduce the amount to an acceptable level – around 1,000; but sticking it in your mouth and then giving it back to your child just adds your bacteria to what came off the floor.

What you do NOT want to do is put hand sanitizer on the object. It’s not made for mouths! Instead, travel with spare pacifiers and sippy cups; use water to rinse off food and objects when possible. Really stuck? Wipe it off with a paper towel and keep your fingers crossed!

– Dr. Michael Roizen and Dr. Mehmet Oz