The Healthy Door Knob, a Fascinating Home Fact
It is logical that door knobs would be covered with bacteria from the many hands that touch them, but do you every think about that before you put your hand on it? This is a problem that can’t just be ‘handled’ by a napkin or by opening the door with your pinkie. We are in luck, nature has provided us with a simple solution to this problem, so we don’t have to worry as much!
Ions of several metals including brass and copper are antimicrobial, that is, they kill bacteria. It is because of the “Oligodynamic Effect”. Wikipedia defines the effect as “a toxic effect of metal ions on living cells, algae, molds, spores, fungi, viruses, prokaryotic and eukaryotic microorganisms, even in relatively low concentrations.”
If you ever see a doorknob made from stainless steel or aluminum, beware… it is probably loaded with bacteria, some surviving for more than a month. A study of hospital doorknobs showed that brass and copper impede bacterial growth, while aluminum and stainless steel let the bacteria go crazy. In fact, within 8 hours a brass door knob will be completely disinfected, while aluminum and stainless door knobs may never be. Unvarnished brass is the most antimicrobial of all the metal choices for a door knob. Brass is best for health!
Sources: wikipedia.com, almostscientific.com, houselogic.com, tested.com