When you reach for an ice-cold soda, you should be aware of the potentially dangerous contaminants on your soda can. Reader's Digest health and safety investigator Caitlin Hoff explains that she always cleans off her cans before drinking out of them or transferring her beverage into a fresh glass, as she feels the cans will inevitably be covered with contaminants.

In 2013, a team of North Texas investigators tested 20 soda cans sourced from various locations. The petri dish with a sample from a corner market grew mold, a college campus' energy drink had yeast on it, a restaurant chain served up a can contaminated with staphylococcus, and a gas station energy drink tested positive for coliform, a bacteria found in animal intestines.

Dr. Cedric Spak, a specialist in infectious diseases at Baylor University, says that running water is one of the most effective tools you can use when cleaning your can. While you may be tempted to use more heavy-duty cleaning tools other than a stream of water, it may not be advisable, as it isn't wise to put potentially caustic cleaning chemicals anywhere near your mouth.