How long germs live – and what kills them

Ever wondered if you’ve done enough to eliminate troublesome germs? Our scientists reveal how long germs can live for and how to stop germs spreading.

July 29, 2019

Cloth being wiped in bathroom
In the home

Nobody likes getting ill, so reducing germs is important for your health. But do you know how long germs can live for, and how to really kill them?

How long do germs live?

Here’s the bad news - some germs, like bacterial spores, can survive indefinitely. The lifespan of germs varies so much that some - for example E.coli and Salmonella may only live for around 20 minutes when actively multiplying, while other bacteria can become dormant and actually survive millions of years!

Here’s an example of how long different germs live:

  • Salmonella and campylobacter: Usually less than four hours, though they have been known to survive for up to 50 days on dirty surfaces.
  • Norovirus and clostridium difficile: More than eight hours – and some studies have revealed they can live for up to five months.
  • Staphylococcus aureus (MRSA): Seven days to seven months.
  • Influenza virus: Around 24 to 48 hours.
  • Cold virus: They survive for around seven days, but lose the ability to infect people after 24 hours.

How long do germs live on clothes?

We wear clothes every day, but have you ever considered how long germs will survive on them? The survival of germs on fabrics depends on several factors:

  • The type of fabric. Germs tend to live longer on cotton for example, as it holds on to residual water and has a very high surface area. By contrast, germs won’t live as long on polyester because it doesn’t absorb as much water.
  • The cleanliness of the fabric. Fewer bacteria will survive on very new, clean fabric whereas older, worn fabrics may have ‘invisible dirt’ that protects germs.
  • The humidity. Not only can mould survive on clothes stored in humid environments – it can actually grow.

How to stop the spread of germs

While germs will always be around the household, you can take a few simple measures to stop them from spreading:

  • Washing your hands is the most important. Always wash your hands after going to the bathroom, and before and after handling food. Try and washing your hands thoroughly for 20 seconds.
  • If you have a cold or cough, use a tissue – and encourage others to do the same. Put the tissues in the bin when you’ve finished with them.
  • Clean ‘high-risk’ areas - like the toilet and kitchen countertops – thoroughly with a detergent cleaner or disinfectant.
  • Pay particular attention to damp areas, where germs tend to grow. Clean the area thoroughly with detergent or disinfectant and wipe dry. Also make sure cloths, mops, kitchen towels and sponges can dry between uses. You could also put cloths in the washing machine on a 60C cycle to help get rid of germs.
  • Keep wet areas of the bathroom clean and as dry as possible to discourage mould growth. Wipe down grout and the shower tray with detergent to remove residual soap scum and dirt that could encourage bacteria growth. Open the window after using the bath or shower to let condensation escape.
  • If people in your household are ill, try and wash underwear separately on a 60C wash with a bleach-containing detergent.
  • Keeps pets away from food storage areas - and always wash your hands after handling pets.

How to kill germs

If you really want to blitz germs as much as you can, there are a few ways to do it:

  • Most germs are rapidly killed by temperatures of 60C and higher.
  • Keep places dry and airy. Drying clothes and towels rapidly in a tumble dryer or on a line in sunshine will kill many germs.
  • In many cases, washing with soap and warm water will remove many germs from surfaces – and an effective disinfectant or bleach will kill further germs. Bleach-based washing powders like Persil Bio will also help to control germs in the wash and some can be used for disinfection when used as a pre-soaker.