How Far Do Germs Travel When You Cough or Sneeze?

Even if you’re stuck at home, you’re not off the hook when it comes to spreading (or catching) sickness. Droplet-borne illnesses like the common cold, influenza, and, yes, the novel coronavirus, spread when someone coughs or sneezes, and they can linger on surfaces for hours or days afterward. 

But how far, exactly, can droplets travel when you cough or sneeze? And more importantly, how should that distance affect your home hygiene routine if you or someone in your home might be sick? Here’s everything you need to know about keeping your space sanitary when somebody’s generously sharing their droplets. 

Dr. Elizabeth Scott, professor of microbiology at Simmons Center for Hygiene and Health in Home and Community at Simmons University in Boston, says as a general rule, droplets can travel between three and six feet from someone’s nose or mouth onto a surface or another person. (That’s why the Centers for Disease Control currently recommends maintaining six feet of personal space to curb the community spread of COVID-19.)

One easy way to help keep germs from traveling (and, ultimately, infecting someone else) is to use a tissue when you sneeze or cough, then disposing of it immediately after and washing your hands. Just make sure to have enough tissues on hand, since germs can stay viable on soft surfaces. The International Forum on Home Hygiene recommends avoiding the use of handkerchiefs when you’re sick, since you’re less likely to spread droplets if you throw away a tissue after using it once. When you use a tissue, always throw it away immediately in a trash bin with a disposable liner or bag instead of leaving it on another surface.

You can’t always predict when a cough or sneeze is coming on (and the most sudden sneezes seem to attack suspiciously when you have your hands full). And you definitely can’t control roommates who won’t take their health seriously. If someone in your household is sick or may be sick and you want to avoid accidentally infecting the other people who live there, you need to be extra vigilant about disinfecting surfaces after someone sneezes or coughs into the open air.

A note: If you’re sick, the very best way to avoid spreading the illness to the people you share your home with is to isolate yourself in another area of the house, and use a separate bathroom if you’re able—but we know that’s not always feasible for every person and every home. Read more tips for sharing a home with a sick person.

If you’re sitting on the couch and then disperse droplets, consider the surfaces within a six-foot radius and disinfect accordingly. Did you sneeze in the general direction of your coffee table and side table, or on your couch pillow and throw? Then disinfect those hard surfaces and toss the soft ones in the laundry. If you’re in the kitchen doing dishes and don’t cover your mouth or nose when you sneeze or cough, that might mean you disinfect your knife block, faucet, and counters before someone else can touch them—and, of course, your hands and the dishes. 

Since germs can survive outside the body for hours (or days) on dry surfaces (the novel coronavirus can remain viable on hard surfaces like plastic and stainless steel for up to 72 hours), practice targeted hygiene and disinfect affected areas as immediately as possible. 

Keep in mind that cleaning and disinfecting are totally different things. Just because you wiped a surface down and removed all visible signs of your sneeze doesn’t mean you’ve nipped the problem in the bud. To make sure you’re actually killing and removing droplet-spread germs, you have to use disinfecting or sanitizing methods.

For hard non-porous surfaces, like a glass coffee table or varnished wood tabletop, you can use an EPA-registered disinfecting product, a diluted bleach solution (the CDC has a recommended ratio for disinfecting with bleach), or isopropyl alcohol in a concentration of at least 70 percent (70 percent alcohol is actually better at disinfecting certain germs than higher concentrations).

To sanitize soft surfaces, like a throw blanket or pillow, you can machine-wash them in hot water. If your washing machine has a sanitize cycle, or you have access to liquid laundry sanitizer, you can use those treatments as well. If you’re not able to machine-wash, or you sneezed on a surface like your sofa, you can use a clothing steamer or iron to treat your fabric surfaces with high heat and kill germs.