Dangerous bacteria in air-con: drivers urged to get theirs cleaned

Dangerous bacteria

All sorts of nasties can come out of your car’s air-con (Picture iStock/Humonia)

Do you know what’s living in your car’s air-con? You may never have considered it but a car’s air-conditioning system is a haven for bacteria. Scientists have even discovered that some of the bugs can be dangerous, leading to meningitis, urinary tract infections and sceptic arthritis.

Our expert has already written this useful guide on why you can’t expect air-conditioning to work effectively if it’s not regularly serviced. But new research has found out exactly what inhabits our air-con. In America, where air-con has been common in more vehicles for longer, they even have a name for the effect that exposure to these bacteria can have: Sick Car Syndrome.

What is the most common bug in our air-con?

The micro-organism found most frequently when London Metropolitan University scientists tested in-car cooling systems was Bacillus Licheniformis. This bacterium lives in soil and in birds’ feathers. Although it sounds pretty revolting, it’s actually not that harmful to humans. Boffins have even been investigating whether it can be used to remove plaque from teeth.

What about the dangerous bacteria?

The next most common bugs found are from the Bacillus family. Bacillus Subtilis exists in soil. However, it is also lives in the gut (and therefore faeces) of humans. And it is very hard to kill: experiments have proved it’ll even survive in space!

Dangerous bacteria

Are these chaps currently inhabiting your air-con? (Picture iStock/Chiari_VFX)

It’s closely followed by other members of the Bacillus family. The spores of this regularly contaminate raw foods and in extreme cases can cause stomach ache, diarrhoea and vomiting. Bacillus bacteria have links to a wide range of infections including meningitis and septicaemia.

How was the research conducted?

Scientists from London Metropolitan University took 15 cars and examined their air-conditioning filters. They found micro-organisms in all of them. On average cars had 1.6 kinds of bacteria in their air-con. Drivers in Plymouth had the most contaminated cars followed by those in Dundee. Cardiff drivers had the cleanest.

Senior lecturer specialising in microbiology at London Metropolitan University, Dr Paul Matewele, said: “Some of the bacteria found has links to animals, the gastrointestinal tract of humans and some infections that could cause a lot of harm to individuals, especially those with a compromised immune system. The study highlights that air-conditioning systems are suitable breeding grounds for bacteria. I’m sure if car owners knew what they were blowing out of their air-conditioning’s vents they would think twice before switching it on this summer.”

What can drivers do?

It’s recommended that car air-con units are serviced every two years. That’s because air-con contains refrigerant which slowly leaks away, reducing the system’s ability to cool. In addition to what’s known as a re-gas, many garages will also perform a bacterial cleanse.

This is where they put a cleaner through the system to kill the bacteria. These build up over time because it’s a frequently warm, moist environment with lots of nooks and crannies to harbour germs. Some of these are odourless but some will cause the stale smell that sometimes comes out of a car’s vents.

Is there a DIY fix?

Garages will frequently charge around £20 to perform an air-con bacterial cleanse. However, from £5 upwards you can buy aerosol treatments that claim to clean cars’ air-con. With the engine and air-conditioning running, you place these in a closed car, set them off and leave them for 10 minutes so the gas can circulate through the car’s system. Some people swear by them, others speak less favourably.

12 comments on “Dangerous bacteria in air-con: drivers urged to get theirs cleaned

  1. Steve Michelle 01/06/2018 6:34 AM

    Get it done profesionally, you need new filters too, so worth spending out for a clean system.

  2. Andrew Davidson 09/08/2018 7:20 AM

    Most cars have some form of ventilation or heating system. Is the problem confined to vehicles with air-con?

  3. peter 10/08/2018 7:58 AM

    very interesting and makes good sense, £50 re-gas , worth going the extra mile for

  4. Julia Honeyman-Tate 10/08/2018 12:53 PM

    Thank you for your advice with regard to cleaning Air Com Systems. Will ask my local
    garage to attend to this and to replace the filters.

  5. Jeff Kendrick 12/08/2018 8:39 AM

    Why haven’t we heard of this before?
    It seems there’s always someone coming up with yet another way of fleecing more money off the motorist.

    • paul stott 21/02/2023 2:56 PM

      Your 100% correct BMW charged me £25 to clean mine I thought this reasonable Toyota charge my 80 year old mother £200!!

  6. david page 12/08/2018 9:40 AM

    MY CHILDREN SUFFERED from car sickness on our frequent necessary long distance journeys we discovered the cause
    was psycological ,by giving each a personalised sick bucket the concern about being sick dissapeared and all was well for the future. This was before it was common place to have a/c(such luxury) in cars we could afford.but I appreciate the a/c advice and will include it in my next service

  7. J M Wyber 13/08/2018 8:29 AM

    We were quoted £99 by a Toyota dealership for this service. Is this reasonable

    • paul stott 21/02/2023 2:57 PM

      My 80 year old mother was charged £200 by Toyota!

  8. linda cresswell 13/08/2018 9:53 AM

    Just range my garage and they have quoted £150 + VAT to clean my aircon, is this the going rate for this. My car is 4 years old.

  9. Jerry 14/08/2018 9:58 AM

    Mine stopped working months ago. Will I still suffer from bacteria?

  10. elaine savage 27/08/2018 8:09 PM

    Where can you buy the aerosol treatments from?

Leave a Reply

Your email address will not be published.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>