Are Germs Spread When Laundering Clothes in a Shared Washing Machine and Dryer?

The Scoop on Poop

• The fecal matter in underwear presents the greatest contamination threat and Gerba states that the average pair of undergarments contains a tenth of a gram of bile, which can include such germs as E. coli, salmonella, and the hepatitis A virus. After the wash cycle, some of these germs remain in the machine and are distributed throughout subsequent loads of laundry, while other germs contaminate your hands as you transfer clothes from the washer to the dryer.

Water Temperature

• The University of Kentucky notes that more bacteria survive in cold water than in either warm or hot water and recommends selecting the hottest water setting. However, to effectively kill germs, the water temperature should be above 180 degrees and most residential washers don’t heat water to this temperature. Laundromats use much hotter water settings and studies show that these facilities are less germ ridden than the average homeowner’s laundry room.

Detergents and Bleach

• Detergents remove dirt -- but not germs -- from contaminated laundry. Adding a disinfectant is effective, but only if it meets the EPAs disinfectant requirements. This is verified by an EPA registration number on the product’s label. Since most disinfectants are designed to eliminate germs on hard surfaces only, make sure to select one that can be used for laundry. Chlorine bleach is a cheap, effective disinfectant that kills germs on any temperature setting.

Drying Effects

• The intense heat generated by a clothes dryer makes it an effective germ-killing weapon. It won’t eliminate all of the bacteria but will significantly reduce their numbers. How many germs actually survive is dependent on the size of the load, the dryer’s temperature and the duration of the drying cycle. Don’t overload the machine and use the hottest and longest setting possible – as long as it doesn’t shrink or damage the clothing. The dryer’s exhaust should be properly vented to the outdoors so germs won’t recirculate in the house. Drying clothes outside – while not as effective as a clothes dryer – is an option since the sun’s ultraviolet rays kills bacteria. Ironing and steam pressing are other ways to reduce the germs.