Published by
Stanford Medicine

In the News, Infectious Disease, Nutrition, Public Health

Science weighs in on food safety and the three-second rule

Science weighs in on food safety and the three-second rule

Here’s something that may interest those who adhere to the belief that food dropped on the floor is safe to eat if pick up within a few seconds. An LA Weekly blogger today offers an overview of scientific experiments done to determine if the three-second rule, or any variation of it, will prevent you from eating contaminated food. From the piece:

A few years ago, Harold McGee looked at tests conducted by Clemson University researchers in which slices of bologna and bread were placed onto salmonella-laced surfaces to determine how quickly each item picked up the bacteria. Suffice to say, the longer the items stayed in contact with the surface, the more bacteria they collected. More recently, researchers at Manchester Metropolitan University conducted their own experiment on behalf of household products company Vileda to test the three-second rule and found that certain foods were more likely to pick up the bacteria than others.

According to The Daily Mail, the university researchers went beyond bologna and bread for their study, choosing to test cooked pasta, ham, a biscuit, bread with jam and dried fruit because they’re commonly eaten and because they contain varying levels of water, a “key factor in whether items will sustain bacterial growth in the three seconds before they are picked up from the floor.” As it turned out, that water level, and high levels of salt and sugars, made a huge difference in how much bacteria collected on each food.

Although study results are mixed, another thing to consider is that some viruses seem to need little help spreading, as was the case with a recent norovirus outbreak that was traced back to a reusable grocery bag. In the end, any pleasure gained from eating a tasty morsel from the floor or countertop hardly seems worth the risk.

Previously: Slight decrease in food-borne illnesses, reports CDC, FDA introduces pilot programs to improve methods of identifying foodborne illness sources and Report shows high costs of foodborne illnesses
Photo by Eric Skiff

Comment


Please read our comments policy before posting

Stanford Medicine Resources: