/ Health, Home & Energy

Washing machines – does washing at 60 really banish bugs?

Washing machine

More than a third of Which? members use the 60°C program on their washing machine regularly. But is 60 the magic number when it comes to keeping bacteria at bay? And do washing machines actually reach 60°C?

We asked our members why they choose to wash at 60°C. More than half use this program to wash items like towels and bedding. These are laundry items that are typically associated with germs and for a long time the wisdom has been that we need to wash laundry at higher temperatures if we want to wipe out bacteria.

Normally, we test washing machines using 40°C programs, as modern washing detergents are effective enough to allow people to use 40ºC for almost all their washing needs. Towels and bedding seem to be the exception, due to the perceived advantages of washing at 60.

But can you rely on your washing machine to reach this temperature? And is 60°C actually high enough to kill bugs and bacteria anyway?

Testing top temperatures

We put 12 washing machines to the test and measured the top temperature they reached during a 60ºC  wash and how long that temperature was maintained. Eight of the machines did not get to 60 degrees at all. The lowest top temperature was 43°C.

Most of the machines kept the water cooler than 50°C for the majority of the program. That’s not exactly what you might expect if you’re using the 60°C wash with the hope of keeping your laundry bacteria-free.

Banishing the bugs

Our test results suggest that a typical 60°C wash can’t be relied upon to kill bacteria, especially if your machine only reaches this temperature for a couple of minutes (or not at all).

We asked a microbiologist for advice about ridding laundry of bugs and he explained that the real key to wiping out bacteria is using a good laundry detergent to wash them away. Detergents are much more effective than they used to be at lower temperatures, so even if your machine doesn’t get to 60°C, a good detergent can remove bacteria and viruses.

I very rarely use a 60°C wash at home. I prefer to be as energy and water efficient as I can and use a fast program that washes at 30°C. I used to wonder if I was taking any chances by not using a hotter wash on things like towels and sheets. Now I know that laundry detergent has a major role to play in bug removal as well as stain removal, I just have to always remember to actually put some in the detergent drawer…

Do you wash at 60°C? Which washing machine program gives you the most peace of mind when it comes to keeping your laundry bug-free?

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I generally use low-temperature washes because they are faster, less likely to damage clothes, and cheaper in terms of energy use. However I have been concerned about bacteria build-up/mould/slime in the machine.
Recently I had a very stained large white cotton cover for an armchair to clean, so I put it in on a very hot wash. To my horror it came out with lots of large grey/brown spots (some in a regular pattern, similar to the holes in the washing drum).
I can only conclude that using the hot wash on that rare occasion had dislodged lots of scum resident in the machine which had then deposited itself firmly on the fabric.
I have heard that it may be necessary to do lots of empty hot washes in a row to get rid of all this gunk – sounds expensive and troublesome! Any thoughts?

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Susanc – I think you are right and it is difficult to think of any other explanation of what you have seen.

Frequent maintenance washes are important when routinely washing at low temperature. Grease from our skin – maybe natural oils sounds better – builds up in the tub surrounding the clean shiny drum, and helps bacteria and moulds stick there and multiply. I am not convinced that doing a maintenance wash once a month is enough and I am not convinced that it is essential to run the machine empty. You might not have found out about the problem if you had run your machine empty. Without dismantling a washing machine it is difficult to know how clean the innards are.

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This has solved a mystery. I sent an evening dress shirt to the laundry for a premium-priced professional wash and ironing service. It wasn’t soiled but I was having the suit dry-cleaned and thought it worth having the shirt done properly as well and presented immaculately in a sealed cellophane enclosure for storage until needed again. After I brought it home and opened the brown paper wrappping I noticed that there were lots of off-white/greyish spots all over the front of the shirt. It didn’t occur to me at the time that they were in a sort of pattern. There was a note pinned to the shirt explaining that despite their best efforts the laundry couldn’t eradicate the stains on the shirt. I didn’t do anything more about it and just put it down to experience. I subsequently washed the shirt on its own in our machine on a 60 C cotton wash using Fairy non-bio gel with a small amount of fabric conditioner and ironed it myself while slightly damp [the shirt, I mean] and with a gentle spray-starch application. The results were at least as good as any laundry and the shirt looks perfect again. One never quite knows where dry cleaning services get the laundry done – it’s probably farmed out to local people on piece rates who, as one would expect, try to keep their costs down by generally using a low temperature setting. They might not pay much attention to the cleanliness of their washing machine believing that (a) frequent use takes care of any problems, and (b) this a 40 C wash is good for the environment. Once in a while they probably have to do a hot wash and, hey presto!, the clothes draw out the scum from the drum. I thank Susan C for explaining this.

raj says:
29 March 2015

When the same happened to me I thought it was mould or mildew. In fact the drum bearing was broken and it was bearing grease. Do have that checked. I ruined quite a few shirts.

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Our machine did a perfect wash. The laundry service let us down and won’t get our custom again.

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Bearing grease seems a plausible cause for susanc’s problem. Bearings are usually sealed units but the space between the bearing and seal may be packed with grease. A washing machine engineer would know if this is the case.


Susan if the marks on your cover after washing were greasy it could also be sign that the bearings are going on your machine, if it happens on other programmes as well.

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It is over 16 months since this problem of nominal 60C washes being far from that and Which? said it would be liaising with DEFRA. Perhaps we can have an up-date. The concept that fixed measurements like degrees C can be misused by manufactuers to meet EU plans is deeply troubling.

” 43°CThe hottest temperature reached by a Hoover washing machine on the 60˚C program

Instruction manuals must, however, contain wording stating that the temperature specified might not be reached. When we questioned all the manufacturers involved in our testing, they quoted this clause as the justification for not reaching 60˚C.
This means that the Hoover washing machine that only reaches 43˚C and gets an A+++ energy rating is acceptable under the current requirements of the EU label.

What is Which? doing about this?
The top temperatures reached by different machines in our tests varied by 24˚C. With no law requiring particular temperatures to be reached, manufacturers can, in theory, not heat the water as much to save on energy costs and improve their ratings.
As guidelines are currently so relaxed, we think the energy label is not a transparent and fair way to compare washing machines. Which? has contacted several organisations, including the Department for Environment, Food and Rural Affairs (Defra), which oversees the energy label in the UK.

Defra has confirmed that it will bring up this issue as part of the European Commission’s review of washing machine energy labels, so we’ll be meeting with Defra before that review to present our evidence.”

I am also ashamed to note that despite running this story the Which? website does not actually provide a button for dicovering which machines offer a hygiene wash – generally code for a more thorough wash with longer high temperatures and more rinse cycles. Given the huge rise in children suffering from allergies this would be useful. The 60C testing for washing machines also appears to be have been a one-off by Which? so consumers have no idea as to the actual temperatures reached in this cycle.

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Not only are we washing at lower temperatures, but modern machines use far less water, leading to frequent comments about poor rinsing in Which? reports and by users. It is interesting to compare the amount of water used by a modern machine and mine, which I have had for 33 years (today is it’s birthday). It’s one reason I’m holding on to it. I should point out that I live in an area where there is plenty of water. I appreciate that other areas are not so lucky, but in order to conserve water, perhaps Defra should be questioning the use of drinking-quality water for gardens and flushing the loo.

We now know that the 60C setting on a modern washing machine relates to cleaning performance and not that it washes at 60˚C. At best this is confusing, and I wonder if the same applies with the 40˚C setting. My biggest concern is that our machines are not allowed to accumulate very large numbers of bacteria and moulds anchored by grease, protein and goodness knows what else. This can be hidden from view behind a shiny stainless steel drum and the user will probably be unaware of the problem until there is a smell or the door seal becomes contaminated. I am not convinced that a monthly maintenance wash is enough, partly because I have not seen any evidence. I believe that we should go back to programme settings that relate to the washing temperature and would like to see some standardisation of the time held at this temperature, which can vary greatly between models.

A further concern is what chemicals are used in laundry detergent and even more so in fabric conditioners, which are designed to remain on our clothes after washing. The chemical composition of these products can change without users being aware of this, which is very difficult for users who are suffering from skin irritation or more serious conditions.

I would like to see investigations done totally independent of manufacturers of detergents and washing machines.

As discussed elsewhere, many washing machines are now being designed in a way that makes it difficult or impossible to carry out repairs such as replacing bearings cost effectively, leading to increased costs for consumers and adding to the mountain of waste.

There are so many problems and uncertainties related to washing and though our modern machines are effective in cleaning, we urgently need to start doing some research. Independent research.

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Dieseltaylor – I have now looked back at article the about washing temperature published in the September 2013 issue of Which?

To quote a headline: “MYTH 60˚C KILLS BUGS”

Prof Bill Grant has written in this article: “No one has suggested that heavily contaminated domestic linens should not be treated appropriately. However, are 60˚C washes necessary for sanitising normal linens? Bacterial spores and some viruses are quite resistant to 60˚C. The major sanitising effect of the domestic wash is the removal – rather than the destruction – of bacteria and viruses.”

Dave says:
5 March 2015

I used to sell washing machines for a living and I knew back in the early 90s that they rarely reach the set temperature and if they do, not for long… I have a dog and to be sure, I like to always wash at higher temperatures – often using hotter temperature setting 70 – 80c depending on whites being soiled…. Ive tried the expensive detergents but a hotter temperature is better…

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Preventing dysentery
You can reduce your risk of getting dysentery with good hygiene. You should:
wash your hands with soap and warm water after using the toilet, and regularly throughout the day
wash your hands before handling, eating or cooking food
avoid sharing towels
wash the laundry of an infected person on the hottest setting possible

I wondered thta given the Which? testing regime did not check the 60C wash whether the higher claimed temperatures of 80 or 90c were checked by Which? subsequently. The NHS advice seems particularly clear. Probably help if they made clear what temperature was actually effective – it may be 55C for half an hour posiibly.

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The effect of temperature on the death of bacteria etc. has been extensively studied and the results can be expressed in the form of a ‘thermal death curve’. This depends on the bacterium, so I would not expect a temperature and time to be quoted. The environment is another important factor. I would expect bacteria to be killed more readily in the presence of a laundry detergent than in plain water, especially with a washing powder containing sodium percarbonate or other bleaching agent.

I would be interested to know if there is evidence of disease transmission by domestic washing machines. Bear in mind that our skin is covered in bacteria and so are our houses – particularly floors – even in the cleanest home. Many modern synthetic materials used in clothing would not survive high temperature washing, and woolen garments were traditionally washed by hand at low temperature. As Prof Bill Grant pointed out in a Which? article, the physical removal of bacteria in the washing process is an important way of reducing numbers.

Humans can generally cope with a certain number of bacteria, below a threshold estimated as the ‘infective dose’. In some cases this is low, which is why Escherichia coli 0157 is particularly dangerous in food poisoning.

If someone in the household has a serious infection, disinfection of clothing and bedding before washing would be sensible, in the same way that reusable nappies are disinfected prior to washing.

I am much more concerned that low temperature washing allows a thick coating of bacteria to build up inside washing machines. This ‘biofilm’ can contain huge numbers of bacteria, which could contaminate every load of washing. The user may be aware of an unpleasant smell and/or discolouration of the door seal due to growth of bugs. Routine use of high temperature washes will avoid this heavy contamination.

marco_wm says:
13 May 2015


I think that there are two old fashioned products that are really cheap and effective that no house should be without; bleach and disinfectant.

The reason that people don’t use them is that they are not advertised.

The reason that they are not advertised is because no one company owns the “brand”. So they can’t charge high prices.

At my local saisburys, a two litre of bleach costs about 40p, a litre and a half of disinfectant, 45p.

Thats enough for about half a year!

We are being sold all manner of branded cleaners and what not, and many times the price, which are all a bit less useful than these two (very cheap) classics. Indeed, often the only useful bit in the high price cleaners will be a little bit of bleach. The rest is perfume and flim flam.

At least once a month I use a hot cycle with bleach in my dishwasher. Works wonders. Removes scum, grease and I presume bacteria. For the washing machine, I do the same.

When washing bedding and towels, try mixing up a diluted solution of disinfectant (a whole liter of supermaket disinfectant costs about 40p) and pouring into the pre-wash drawer of your machine. I dilute it about 10 to 1 before pouring it into the drawer. The machine then adds its own water for the pre wash. The advantage is that this cleans the clothes AND the drum, pump, pipes etc.

After the pre wash is done, the main wash starts, which washes away the smell of the disinfectant.

If you hate the ‘hospital’ smell of disinfectant, you can now buy disinfectant different aromas rather than just pine.

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I agree about the value of bleach. Used on a damp cloth it can be used to clean work surfaces and chopping boards after handling raw meat, especially chicken.

I am not convinced that it is necessary to treat bedding and towels with disinfectant, unless they have become contaminated with faeces or used by someone with a serious infection. Most people do not disinfect clothes and bedding before washing, yet they don’t become ill.

Bleach used in small quantities is environmentally safe because it rapidly breaks down. Disinfectants may persist and when they get into water courses such as rivers they can do a lot of damage. They have a place but should not be used unnecessarily.

If you do a hot wash once a week then a washing machine will stay clean without using bleach or disinfectant.

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wavechange – Research shows that humans mar clothing to the extent of 1gm per day. US research
My guess is we are talking sheets and underwear. Unfortunately I do not have the source for the original research.

I agree that most people do not suffer as a result of this – any more than other animals – from contact with faeces.

The summary is perhaps overdramatic and actually only really suggests better studies are required according to IFH who also mention:
“we must bear in mind that oxidising microbiocides such as chlorine bleach are used at concentrations ranging from 0.5 up to 50,000 ppm, and are a vital part of our armory to prevent infections in healthcare settings, water treatment, the food and pharmaceuticals industries – and also in the home when used in a targeted manner to prevent the spread of infectious germs.”

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Thanks for the link, DT. Having read this paper, my first reaction is that the study is flawed in many ways.

The authors have compared different countries where there different infection rates could relate to numerous factors other than use of bleach. A much better study would, in my opinion, have been to compare infection rates in children who live in homes/schools where bleach is used or is not used in a single country, or to do the same studies in different countries.

At the most basic level (1) the authors do not say whether their studies relate to use of hypochlorite bleach or peroxide bleach, both of which are in common use, and (2) how the bleach is used. I don’t recall mention of its use in laundry.

In the Discussion section the authors state: “However, the evidence is inconsistent across countries, the health effects are rather modest, and the exposure and health assessment and cross-sectional design are a limitation, not only in our study but also in the previous studies. Nevertheless, the high frequency of use of disinfecting cleaning products—caused by erroneous belief, reinforced by advertising, that our homes should be free of microbes—makes the modest effects reported in our study of public health concern.”

That’s a good point. Advertising is making us far too concerned about keeping our homes free of bugs. If that’s really important, not only should we disinfect everything but we should replace carpets with vinyl floor covering and fabric/leather sofas with easy-to-clean plastic.

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I agree the test is flawed to a degree but a useful talking point.

This one is closer to home and recent and highlights that nurses are washing uniforms at home on inadequate heating and seemingly some without guidance.

About DMU

Nearly half of hospital uniforms are washed in temperatures too cool to kill bacteria, says DMU research

De Montfort University Leicester (DMU) researchers have recommended there should be national guidelines set for washing uniforms of nurses and other hospital staff after it was revealed 49 per cent of those surveyed did not use water hot enough at home to kill off certain bacteria.

The ground-breaking research, carried out jointly by DMU microbiologist Katie Laird with PhD student Kate Riley and Principal Lecturer John Williams, from the university’s School of Fashion and Textiles, surveyed 265 hospital staff anonymously at four unnamed hospitals in the East Midlands.
They were asked how often they washed their uniforms, the temperatures they washed them at and whether uniforms were washed separately from other clothing.
The results showed 49 per cent of those surveyed did not wash their uniforms at a recommended temperature of 60°C while 40 per cent also washed their uniforms with other clothing. A total of 74 per cent of respondents said they washed their uniforms after every shift, meaning more than a quarter were potentially carrying bacteria-contaminated clothing into another shift.
The four hospitals surveyed offered different washing guidelines or, in some cases, no guidelines at all on specific aspects of uniform care.

The report authors have called for national guidelines to be introduced and have also recommended washing of hospital uniforms is moved back in-house.
It is common for staff to launder their uniforms at home as it reduces NHS costs and is more convenient. The report writers have suggested that moving uniform cleaning back in-house would rule out any possibilities of not meeting a national standard.
The research acknowledges the correct cleaning of uniforms is an important aspect of infection control as uniforms can carry Hospital-Acquired Infections (HAIs) such as MRSA and Clostridium difficile.
HAI’s, caught by patients as a result of treatment by healthcare providers, cost the NHS more than £1 billion a year due to prolonged stays in hospitals while the infection is treated. Older people, the young and people with weakened immune systems are particularly vulnerable to these infections which can cause discomfort or pain and in some cases result in disability or even death.
The report says “the development of national guidelines for domestic laundering of healthcare uniforms would ensure greater clarity for staff on how to launder uniforms”.
DMU student Kate Riley, who is studying a PhD in “Textiles – Improving sustainability of regularly laundered healthcare clothing”, was able to carry out the research with the help of a Society for Applied Microbiology Hardship Grant.
She said: “The study highlights the importance of research in this area to determine the overall effectiveness of domestic laundering and deciding whether a return to in-house laundering is the most appropriate solution.”
DMU’s Katie Laird, a national lead in research into the control of hospital-acquired infections and co-author of the report, said: “We would like to thank the hospitals and staff that contributed to this research. Without them we would not have been able to establish what home uniform laundering practices were taking place and thus highlight an important infection control issue.
“This is especially important due to the increase in Hospital Acquired Infections and their antibiotic resistance.”
Ms Riley is currently carrying out research to discover the optimum wash temperatures and wash times to kill off bacteria as well as the best detergents to use. She is also testing the micro-organism survival rate on different textiles to see which materials could be used in uniforms.
She said: “All textiles react differently in a domestic laundering cycle and it is important that suitable fabric choices are made for healthcare uniforms.”
Dr Roger Salmon, Chief Executive of the Textiles Services Association, welcomed the report saying: “The Textile Services Association represents UK laundry and textile rental companies who provide specialist services to the health-care sector.
“It has long been campaigning for a detailed study to support its considered view that through the vehicle of hospital workers wearing both their clean and soiled uniforms in transit, the potential hazard of cross-contamination is increased. The inability of domestic washing machines to carry out a validated hygienic wash process and the practice of mixing classifications at home further exacerbates the cross-contamination potential.
“As with hospital linen and operating theatre garments, nurses’ uniforms should be laundered to a validated hygienic standard to protect patients and staff.”
Posted on Monday 30th March 2015

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Washing hospital workers’ uniforms is very different from routine home washing, particularly if the workers have any contact with infected patients or facilities they use. I would like to see the risk assessments for letting workers launder their own uniforms. It seems unwise, to say the least.

In the department I worked in, the lab coats of staff working with the most dangerous bacteria were autoclaved (steam-sterilised) at 135°C before sending to the laundry.

Although home washing of hospital workers’ uniforms concerns me, I remain to be convinced that routine low temperature washing in the home is causing transmission of infections, providing that the machine has a regular high temperature service wash with detergent containing bleach to prevent heavy contamination of the internal components with bacteria and other microorganisms.

Angus says:
10 July 2016

Does anyone know why some machines have a “60” setting and immediately next to it a “60 degree C” setting? What is the difference?

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Your question is so open and without any clues as to the makes and models you are referring about its hard to answer you . There are so many possibilities to your question that I will pick one and if it does not apply dont blame me just give me more info . Its possible that they apply to=wash +rinse temperatures this is a feature in US machines but that is only one answer out of many.

dieseltaylor says:
10 July 2016

My Bosch 2000 machine has two 60C settings and the “E” one utilises the hot water fill from my hot water cylinder so my machine does not heat hot water when I already have it “on tap”.

My guess is that this is a way to to let consumers choose a hygienic 60C wash – using that temperature – and the other is a lengthy wash at a lower temperature which will give the optical cleanliness equivalent.

It should be noted strongly that the claimed 60C temperature wash may not actually be near that or if it is only fleetingly. Which? has been extremely unhelpful in not provding this information in its testing. Given the vast numbers of nurses and similar workers were hygiene is the main priority I consider it a disgrace.

Consumers cannot check this data, Which? can, but chooses not to do so. De Montfort University has already highlighted the quality! of nurses laundering at home.

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Yes diesel that could be an answer too , although while searching on the web one site said 60 C is not high enough to kill off all germs and that strong washing powder / bleach etc were needed . The US machines go up to 95 C . I absolutely agree about the NHS and laundries , as a hospital engineer there were two laundries where I worked a regional Central Laundry and a hospital laundry (much smaller ) .The smaller one was needed because where I worked was an infectious disease hospital and I am NOT talking of mumps/measles etc but the most virulent African diseases known to man . if you know hospital procedures then you will know blood samples tissue samples are taken they were disposed in a hospital incinerator but the clothes were cleaned in the hospital laundry . I repaired every conceivable piece of hospital equipment including laundry machinery and as wavechange mentioned Autoclaves . Steam pressure was 120 P/sq in and that was used in the autoclaves and laundry equipment I can assure you that the temperature was a mile above 60C as I got a steam burn and needed treatment . What happens ?? privatisation and the laundries —yes you have guessed it – homeward bound for doctors and nurses to their 60C washing machines , now thats what I call PC and money saving over public safety . its a great life isnt it ?

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Angus – There are now EC standards for washing machines and it is no longer necessary to use 60˚C for a modern machine to achieve cleaning performance that conforms with the standard. I assume that the other setting refers to a programme where the machine does reach a maximum of 60˚C for an unspecified time.

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Once again I will say that nurses in contact with infected patients should not be laundering their uniforms at home. As Duncan says, privatisation has a lot to answer for.

Using laundry detergents containing bleach (generally powders and tablets, but not liquids and gels) will help deal with bugs, though soiled fabrics should be treated using products designed for decontamination of nappies before they are put in the machine.

dieseltaylor says:
11 July 2016

The EC standards are flawed. This was established in 2013 and Which? said it would be writing to Defra as the responsible department.

The driver for the standard was to reduce power usage which was a laudable aim. However there were two flaws exploited by the manufacturors to gain the A+ ratings or/and to lower costs.

1. Removal of the dual hot anf cold input with a mixer valve. Single cold water infill with water heated in the machine. Savings to the manufacturer. Use of low temperatures on nominally hot washes.

2. For those swathes of customers, particularly around the Med, who have solar heated or gas heated water jn store they are now likely to be using a machine which will use electricity to heat water in the machine – not the green solution the EU wanted.

3. The need for heat in the wash cycle has been made by scientists and hygienists covering a number of viruses, allergens, bugs, and moulds. There is an 80+page document I have mentioned here and delivered to Which? in 2013. The German testing consumer body has found one washing machine in 2015 which on its 60C wash carried it out at 27C.

4. The EU needs to have meaningful sysmbols AND proper temperature standards rather than another example of a dubious much fudged standard like the car emissions test. Hot water washing is required by the NHS for staff uniforms whether carried out at home or on-site yet no body warns consumers that not all machines provide the advertised temperature of 60C.

5. I am not in a position to access all the details of all the machines however in the final analysis what a manufacturer claims and what is delivered in the wash are two different things.


In the home setting a 60C wash need not be common but in some households because of the work they do – dealing with animals, care of people, working the soil, drains, – it is an important matter.

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The benefits of hot & cold fill are questionable and have been debated on Which? Convo. If free hot water is available from solar water heating then hot & cold fill will obviously make more sense than using electricity to heat water in the machine. On the other hand, if hot water comes from a tank heated with an immersion heater it is better to heat water in the machine and avoid heat loss in the pipework. With gas water heating, whether it is beneficial to have hot & cold fill will depend on how well the pipes etc are insulated and the length of the pipe between the tank or combi-boiler. In my previous house using gas-heated water was worthwhile but I do not think it would be in my present home because of the length of the pipe run.

As far as I know, a washing machine with hot & cold fill does not use a mixer valve, just a pair of solenoid valves that admit hot and cold water when needed. My old washing machine used no hot water on the 40˚C setting and took in both hot and cold water on the 60˚C programme. The hotter the wash, the more likely it is that a hot & cold fill machine will save money.

As solar water heating becomes more popular we may see an increased demand for hot & cold machines.

rob hender says:
10 April 2017

it denotes a 60 degree centigrade setting as opposed to a 60 degrees farenheit d setting.

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This might address some of the issues raised. A PAS is a Publicly Available Specification – here a Pre Standard. I presume it is a document to describe a standard test procedure to be used, not a mandatory requirement as part of an approvals process (such as a safety standard). For those with access to standards this is 34 pages long.

British Standards Document
PD IEC/PAS 62958
Clothes washing machines for household use. Method for measuring the microbial contamination reduction

IEC PAS 62958:2015 © IEC 2015 – 7 –
SC 59D decided to address the measurement of the microbial contamination reduction in
washing machines by developing a globally acceptable Publicly Available Specification to
respond to the increase in consumer complaints regarding odour from washing machines and
washed laundry caused by presence of microorganisms.


IEC PAS 62958:2015(E) specifies a test method for measuring the reduction of microbial contamination in clothes washing machines and of the possible cross contamination to uncontaminated load. This PAS applies to clothes washing machines for household use, with or without heating devices utilising cold and/or hot water supply. It also covers washing machines which specify the use of no detergent for normal use. This PAS applies also to washing machines for communal use in blocks of flats or in launderettes. This PAS does not deal with professional washing machines nor with commercial laundry operations associated with food service, hospital linens or other non-residential applications. It also does not address the needs of persons with specific health conditions requiring special sanitization and/or disinfection techniques. This PAS does not specify safety requirements and does not deal with performance of washing machines measured under IEC 60456 nor with effects on fabrics.

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Thanks Malcolm. We do need public access to standards relevant to the general public.

In the same way that failure to clean lint filters is a risk factor for tumble dryers catching fire, failing to carry out periodic maintenance washes is likely to be the main problem with contaminated washing machines. For the benefit of those who are new to the problem, washing machines used at low temperature become coated on the inside with a sticky biofilm containing bacteria and other microorganisms when not in use. Most of this is hidden, though nasty smells and discolouration of the door seal are sure signs of a contaminated machine. Using liquid or gel laundry detergent exacerbates the problem because these contain no bleach. Machine manufacturers generally recommend a monthly maintenance wash on a high temperature setting to keep the innards of the machine clean.

I have recently bought a new washing machine that has a ‘hygiene’ light, indicating that a programme using a temperature above 60˚C has not been run for a long time. It advises that in order to prevent bacteria and unpleasant odours building up in the machine, it should be set to Cottons 90˚C using powder detergent. The significance of powder detergent is that it contains bleach, which will help kill bacteria. It’s a good start, though I would recommend doing a maintenance wash more frequently.

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I wonder how many people would actually want to look at standards, understand the way to find all relevant standards and then understand and interpret what they say? However, it is very unlikely that standards will be made free to everyone; they are world wide, all countries would need to participate, and the huge funding necessary to replace sales and subscriptions would then fall on the hapless taxpayer who, i suspect, would think of more appropriate use for their taxes. 🙂

However I think legitimate enquiries about what standards have to say should be answered by organisations that have both access to them and understand where to find the information required. Which? say they have access to all standards and should have the expertise to handle them as part of their normal testing and investigation of products and services, so they could respond to members couldn’t they? Or BSI could offer this service. I have, on occasions, had good and constructive responses from BSI, and from AMDEA.

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As I’ve said when we were discussing tumble dryer fires, British Standards Online is available for home use to individuals who are registered users of the Glasgow Libraries. Unfortunately my temporary membership of the Mitchell Library has expired. My nearest city library offers on-site access and is still thinking about online access, but perhaps it would be provided if there was more demand. Of course there are other standards we need access to, but it’s good to make a start and set a precedent. As you say, there would not be many who want personal access to standards, so let them register for the service and leave the funding of publication and updating of standards as it is at present. There is no need to hit the taxpayer.

For me, this is all about fighting for freedom of information that can be of public interest and should be in the public domain.

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I have currently found access to standards – read only. The problem if access to all standards were free is that many people would not purchase them so the current funding would be substantially reduced. And we would need international agreement – standards are international and funded in the same way elsewhere I believe. So while I would like universal free access I do not see it happening. You can look at contents and abstract for free, but as with many scientific papers you have to pay for the full text.

I believe Which? should help members via their access, as many issues with products in these Convos would benefit from knowing the content of standards – tumble driers, washing machines, and I’ve found BS EN 16086-1 on soil improvers and growing media. Remember a report on best buy garden composts? I wonder if Which?’s test lab referred to this for a procedure. Interestingly (really?) the UK had to adopt this standard but voted against it because the test plant used – Chinese cabbage – was not sensitive to some of the pesticides currently found in composted materials and there was poor reproducibility between laboratories. Which just goes to show how tricky it can be to do reliable testing in some cases.

I still wait to hear if Which? will test the fire resistance of faulty Indesit machines to provide some information on their compliance with the standard.

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If we insist on companies continue to pay for access to standards they could be made freely available to the public. I have explained elsewhere how open source publication has revolutionised science publishing. The authors pay to publish and everyone enjoys free access.
The purpose of an abstract is to help the reader to decide whether to obtain the full article.

As far as I’m concerned we know that the standard for tumble dryers is not satisfactory because there is no requirement for an interlock or other device that would require the user to clean the lint filter before the next cycle, decreasing the danger of fire. Better exposure of standards would allow more people to read them and identify the problems. There is now a vast number of recently retired people who don’t just want to watch soap operas and check their Lottery numbers, who would be happy to do unpaid work for common good.

Back on topic, can you explain why only the abstract of a Publicly Available Specification should be available? 🙁

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Many companies would use the free access route – just like the “public”.
“Publicly Available Specifications (PAS)

“International Standard (IS)
A Publicly Available Specification is a publication responding to an urgent market need, representing either:
a consensus in an organization (e.g. manufacturers or commercial associations, industrial consortia, user group and professional and scientific societies) external to the IEC or
a consensus of experts within a working group.
A Publicly Available Specification does not conflict with an International Standard however competing Publicly Available Specifications on the same subject are permitted.

The objective of a Publicly Available Specification is to speed up standardization in areas of rapidly evolving technology.

A simple majority of the Participating Members of a Technical Committee or Subcommittee approve the document. An IEC-PAS responds to an urgent market need for such a normative document and is designed to bring the work of industry consortia into the realm of the IEC.

PAS may either be the result of deliberations in a working group or project team, when it is felt that an intermediate publication released widely might be useful, or it may also be a dual-logo publication, developed by an external organization in A- or D-liaison with the committee concerned. In the case of the former, the committee may decide to designate the PAS as a Pre-standard.”

I don’t think their is any implication it should be free of charge, but that anyone can get hold of it. Some documents will not be publicly available. Standards in preparation for example until they reach a draft for comment stage.

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Thank you. If the companies would not pay for the information they need to ensure that their products comply with legislation then raise the funding by taxing them or by some other means.

I may have mentioned that British Standards are copyright, which is why I paraphrased information about the tumble dryer standard I reported on. I doubt that Which? would be permitted to pass on the full text to us.

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I am suggesting when we have questions involving products and what standards say, Which? consult their standards and tell us. I asked them about what standards say about fire in tumble driers; they seemed unable to reply as Which? so asked BSI who gave an answer that did not address the question. I then got access to the tumble drier safety standard and quoted earlier what it had to say about spread of fire and relevant tests on materials. That is what I had hoped Which? would tell me – as an example.

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How did you get access to the standard, please?

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I have, for now, found a way. However, when I asked Which? if they had access to all relevant standards they replied that the had. I would suggest that when Members at least, and why not Convo contributors, ask questions that concern standards they have the facilities to answer them. It can be a little time consuming tracking down the appropriate standards(s) but in conjunction with the test laboratories they employ and their expertise they are better placed than we are.

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Whatever the merits of judging the performance of a washing machine by the effectiveness of cleaning, it is not acceptable to use numbers that look like temperatures but are not. Moving to the current standard presented the manufacturers with a problem because previously, automatic washing machines did make use of different temperatures in their programmes.

Looking at my new machine, the labelling is not intuitive. I had assumed that the labels 60˚C and 40˚C (which are in boxes) might be temperatures but referring to the booklet I learn that these settings will use lower temperatures and the wash performance is the same as the standard Cottons 60˚C programme, which is shown on the machine as 60, not 60˚C. I would like to measure the temperature attained and how long this is maintained to know what is happening. I’m not sure of an easy way to do this and nearly wrecked my thermocouple probe last time I checked the temperature of a machine.

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Well wave change – you as a Professor will find this technically “right up your alley”–the Columbus -a novel sensor system for domestic washing machines invented by various Professors and high tech individuals– archives.sensormag.com/articles/0602/32/main.shtml . Meanwhile I will look for a more up to date version.

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Thanks Duncan. I’ll have a proper look later.

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Fascinating. This describes a small device that measures not just temperature but a variety of variables during a washing cycle and is capable of surviving in what is physically and chemically a harsh environment and doing the job without modification of the machine. Not having the resources I think I’ll have to carry on with simple temperature probes.

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May I point out that the microbiologist that Which? used his speciality was nothing to do with hygiene and was in an article lauding the use of the 40C wash and by inference the value of Which? testing solely on the basis of optical cleanliness at that temperature.

Bearing in mind the spread of antibiotic resistance I refer you and everyone else to this summary from a reputable source:

” As outlined in the introduction, in the past few years, infectious disease has moved back up the health agenda, prompting governments and health agencies to invest in hygiene promotion as a means of reducing the infectious disease burden. A number of examples illustrate why and where effective hygiene practices associated with clothing and household linens are particularly important:

The proportion of people living in the home and general community who have reduced immunity to infection is increasing. Although the risks of exposure to pathogens are the same as for everyone, these people are more likely to develop infections as a result of microbial exposure, if hygiene procedures such as laundering of clothing and household linens are not implemented or are inadequate.

New MRSA strains are now circulating in the community. These community strains (CA-MRSA) differ from hospital strains in that they are just as likely to affect young active people as the elderly or infirm. Although CA-MRSA strains are now a major problem in the USA, they are still relatively uncommon in Europe and elsewhere, and there is thus still an opportunity to avoid the problem escalating to a similar same scale. The findings of this report suggest that transmission of S. aureus (including MRSA) via clothing etc is a particular risk and that effectiveness or otherwise of laundry hygiene processes could be an important factor in defining the rate of spread of these strains.

Technological and policy changes are being introduced to reduce costs and/or environmental effects without regard to the potential impact on disease risks. There are indications that low temperature laundry process may be insufficient to eliminate pathogens from fabrics and that such processes may increase the risks of spread of infection via clothing and household linens.

In the UK, US and elsewhere, healthcare workers frequently launder their uniforms at home. This report shows the extent to which their clothing can become contaminated by contact with infected patients indicating the importance of effective laundry hygiene at home. A UK questionnaire study of nurses working in 3 hospitalsi indicated that 31% of nurses did not use the hospital laundry whilst a US survey of nursing staff indicated that 26% home-laundered their scrubs.ii

Apart from infectious disease, a parallel agenda of global importance is sustainability. Protecting health by preventing infection is in itself a more sustainable approach than treatment. Equally however, hygiene measures must themselves be sustainable. The issue of hygiene in relation to sustainability is assessed in a 2010 IFH report.iii

From the data presented in this report, it is concluded that, although laundry processes should be able to deliver clean fabrics with minimum, use of water, power and chemicals, it is equally important to ensure that laundered clothing does not represent an infection risk. After wear or use, clothing and household linens, most particularly that which comes into contact with the body surfaces, should be laundered in a manner which not only renders them aesthetically clean, but also hygienically clean i.e. free from pathogens.

To achieve this, there is a need to ensure that laundry products are clearly labelled so that consumers can understand whether, and under what laundering conditions, their laundry products can be expected to produce fabrics which are “hygienically” as well as visibly clean. It is also important for regulatory authorities to recognise that the “hygienic cleaning (i.e. biocidal/germ removal action) of laundering is achieved by a combination of heat, rinsing, detergent and chemical oxidative action. This is a very different situation from the biocidal mode of action of disinfectants including antibacterial products) on hands and environmental surfaces. ”


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My opinion is that we as a society are far cleaner and more hygienic than previous generations and modern washing machines and steam irons have enabled this with simplicity and economy. People change and wash their clothing much more frequently and, for most purposes, frequency is as important as temperature. Laundering all the bedding is no longer a chore of immense proportions and the expense and inconvenience of using a commercial laundry service is avoided. Generally, the utensils we use, the hygienic products that are available, the way we conduct ourselves, the indoor life, and lots of other things, reduce the tendency for spillages and messes. Air-conditioning, appropriate toiletries, and less manual labour have reduced perspiration problems. And society is now much more appearance-conscious so clothes are replaced more frequently anyway. The washing action is far more efficient in modern machines, the detergents used are much more effective, and steam ironing is now the norm. So I do not think the standard 60 setting for most washes is bad at all. The facility is available for a hotter or a longer wash and for better treatment of specific fabrics. For those working in certain occupations where infection and contamination are a risk [including production kitchens] then I would expect them to be responsible and either use the sterile laundering services available at most such sites or ensure that if they wash their garments at home they use the right programme and detergent products which couldn’t be easier or safer nowadays.

Addendum : (I had to break off and attend to the mighty Amazon that was about to disgorge my orders elsewhere).

I meant to add that people have a far higher standard of personal hygiene these days with [at least] daily showers and hair-washes, and are generally wearing proper protective clothing if their work involves dirty or unhygienic conditions. Our homes and workplaces are much less insanitary with proper cleaning routines and a sense of pride in good hygiene standards. More fresh produce and food stuffs are packaged than ever before reducing the introduction of dirt into the home. The incidences of scabies are now extremely rare and although I have read that nits, fleas and head-lice are recurring problems effective treatments and preventive measures are rapidly introduced upon discovery. Now that men’s office suits can often be put in the washing machine that soiled, stinky and repellent work-wear is a thing of the past [and the opprobrium of adjacent colleagues will soon deal with any malingerers]. So in my view, frequent washing on the 60 programme [even if it does not reach more than 50 degrees] is good enough and any bad soiling can easily be dealt with with a minimum of labour and a high degree of efficacy [it doesn’t matter if the grass stains are not expunged from your cricket whites].

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I am concerned about healthcare workers taking their uniforms home for laundering, but have no idea what regulations and policies are in place. In addition to NHS staff there are plenty of workers in the private sector including care and nursing homes, private hospitals and dental practices. The university department where I worked had its own policies for staff working with hazardous bacteria and other microorganisms. Overalls and lab coats were steam sterilised before being sent to a local company for laundering.

I do see a need to monitor the effect of current domestic laundry practices on the risk of spreading infection. In recent years, the popularity of laundry detergents lacking bleaching materials has increased. Short washing cycles have become popular. Low temperature washing has become the norm for most people. If users don’t carry out ‘maintenance washes’ the insides of their washing machines will become coated with a slime containing huge numbers of bugs that could contaminate the next load. 🙁 I don’t see this mentioned in the IFH report, which is not published in a peer reviewed journal.

Criticise Bill Grant if you wish, but at least he has pointed out that washing process is the main way of removing bugs from fabrics, a point missed by many writers. He has also pointed out that we cannot rely on 60˚C to kill bugs: https://conversation.which.co.uk/home-energy/washing-machines-60-degrees-kill-bugs-detergent/#comment-1402751

I believe that the way forward is to investigate the issue and if deemed necessary to introduce new standards for washing machine programmes, that all manufacturers would have to comply with.

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Wavechange – I share your concern over the home laundering of work-wear in medical and personal care occupations. I would have expected that, following a risk assessment, appropriate procedures and safe working practices would be incorporated into each employer’s health and safety at work management policy and practices documentation with reliable procedures in place to check for compliance. This should certainly be the case for any organisation subject to an audited quality assurance system but for the rest it might be wishful thinking. Small establishments might not have satisfactory sterilising equipment on site so would rely on commercial laundry services and an appropriate wash specification. Thousands of health and domiciliary care workers are not site-based and have no practical alternative than to launder their uniforms at home. The supply of disposable aprons and overalls has reduced the risk of soiling and contamination of their outfits but they should still be laundered at a high temperature.

Although low temperature wash programmes are available on most machines, I don’t know how many people actually use them or mostly use the 60 programme that is the default setting on many machines. Obviously there must be many who cram the machine full and set a 30 degree wash; clearly that will not be hygienic for under-garments, night-wear bedding, towels, and such like, and will not do for shirts and blouses where no under-clothing is worn, nor for jeans, trousers and any close-fitting clothes. I would consider all children’s clothes should be washed on the 60 programme as a minimum. Strangely, the dishwasher delivers a much hotter wash than most washing machine programmes but the volume of water used is much less.

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John – The reason that a dishwasher washes at higher temperature is that it relies on the action of aggressive chemicals and hot water sprayed on the cutlery and crockery. For research purposes I have tried my dishwasher on the 35˚C setting for the first time and it did not even fully dissolve the tablet, never mind cleaning the crockery. I will go back to using 65˚C.

Even if healthcare workers are given a procedure for laundering their uniforms, I don’t know how many would follow this. For years, instructions provided with tumble dryers have indicated the importance of cleaning the filter but not everyone does. This is why I have advocated the need to redesign dryers to force compliance or move to better designs that have no high temperature heater – heat pump dryers being the obvious example.

If uniforms have to be laundered at home, I believe that chemical disinfection is the best option.

At one time, a setting of 60˚C meant that a household washing machine would achieve that sort of temperature – maybe plus or minus 5˚C because simple thermostats are not accurate. The holding time at which the temperature is maintained would vary with model. Modern machines are tested for cleaning performance, yet we see meaningless temperature settings. My recent Miele machine has 60˚C and 60 settings. From what I have read, the 60˚C setting is a long wash at lower temperature and the 60 setting corresponds to 60˚C. 🙂 I must check with a meter but need to buy a new thermocouple probe. I’m unhappy about manufacturers showing meaningless ‘temperatures’ but have sympathy because the problem has arisen because of new testing standards. Not all machines have a default programme and mine, for example, stays on the setting last used.

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I repaired all types of hospital laundry equipment as there were two laundries in my hospital GROUNDS – a hospital laundry and an area central laundry . All local hospital soiled items , doctors/surgeons / nursing staff , laboratory staff etc had their clothing laundered at the small local laundry –why was it there ? -easily answered as it was an INFECTIOUS Disease hospital . Not only known British diseases but all exotic diseases , thats why it had a large biological technical staff as well as an “Animal House ” I repaired the autoclaves that after repairing were tested to a certain temperature as well as worked in the animal house on equipment . very high standards were employed in both the collecting and washing and ironing of soiled clothing , I NEVER saw nursing staff take home soiled clothing , as a matter of fact their jobs would have been in jeopardy if they had . The much larger Central Laundry catered for all the Regional ( part of a large city ) hospital clothing , again great care was needed as many women were employed in both. What do you get now ? PRIVATISATION -aka -outsourcing to many commercial companies , I do not believe for one minute they are to the same very high standard –prove me wrong ? I contracted a “mystery ” infection while working there , my doctor when finding out I worked at -******* hospital sent blood samples away not only to a hospital laboratory but to the city health dept. When the results came back he refused to tell me what it was I was suffering from BUT I was immediately banned from going to work and told to stay indoors ,it was 2 weeks or more till more tests relieved I was “cured ” -IE- disease not spreadable . Now its a “save money exercise ” that has failed (in my view ) . It is disquieting that several of the websites exposing faults in the privatization of the British laundry services have been -“404″ ed ” or securely blocked. I have still to talk about the drop in bodily resistance. ALL severely contaminated items were incinerated in the onsite incinerator .

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It is also well established that outsourcing of cleaning services has lead to some dirty hospitals.

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Absolutely right Wavechange .

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Infection-risks-clothing-and-household linens-revised0413.docx

From the site I referenced. There is also an 80 page meta -analysis on the site.

JW you refer to 60 washes but the complaint is that what it says is a 60 wash – that you might think is around 60C it is very probably not. The Germans, having found a 60 wash carried out at a max 27C . They seem to be taking this into account in their scoring ….. which also indicates that they are testing at the 60″temperature”. Which? , unless things have changed. continue with an optical cleanliness test of a 40C? wash.

WC refers to microbiology. I have also researched insects such as bedbugs [and allergens] though not currently a “hot topic” in Europe the high temperatures are required.

Whilst overall the population is fine I suspect that the poorer people , who may suffer ill-health or bad conditions may be the very people who are buying the cheap and probably misleading washers. They are also the people who may have food preparation roles or cleaning roles.

In August 2013 the talk was of Which? having words with defra regarding the new Guidelines which allowed misleading labelling of washes. Despite Which? having two defra big-wigs on Council I have seen neither hide nor hair of an up-date.

I am not paranoid about my health as I am generally disgustingly healthy but my father at 90 was not. I also take a very dim view of organised industry lying.
A 60C wash should be what it claims to be ditto the other temperatures.

If they invent new symbols like O60 to indicate an optical cleanliness equivalency I have no problem with that concept. And they can make the O numbers defaults provided it is clear where the hygiene washing buttons are.

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Patrick – I was aware of the controversy over a “60 programme” [avoiding the use of degrees] and in a previous post I did say that might mean no more 50 degrees Celsius.

What people need to know is that a 60 wash programme is a good general programme for most purposes but is not hot enough to thoroughly cleanse clothing and bed linen

I think most washing machine users have plenty of common sense and are capable of selecting the best functions and programmes offered on modern machines, and can follow the laundry instructions on most garments and other washable items. There seem to be very few hygiene incidents attributable to poor laundry practices. As I tried to imply, steam ironing will also help to purify the laundry – although I know a lot of people do not iron the things that would benefit the most in terms of hygiene.

So far as I am aware no manufacturer refers to a “60 deg C” wash – they refer to a 60 wash, which I agree is meaningless. It would be better to have min, cool, warm, hot, very hot, and max rather than pointless numbers but since machines are made for international markets and territories with different languages, and where either Celsius or Fahrenheit could apply, something non-denominational is required.

Maybe one of the problems is that compared to our parents’ and previous generations we have lost a lot of our immune system protection but in exchange we are a lot cleaner.

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That last sentence could be a parable John, of which I agree completely. We all live in a body not a Superman outfit and a ticket in the pocket saying– Planet Krypton to Earth –non-returnable.

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I would like to see misleading temperatures removed from washing machines and instructions and said this long ago.

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Perhaps it would be useful to have a look at manufacturers’ recommendations for washing. Some fabrics, notably women’s clothing, must be washed at low temperatures to minimise damage and washing at 60˚C is out of the question. In some cases, using a laundry detergent containing bleach is inadvisable too. Low temperature washing need not be a problem, but it takes longer to remove dirt and bacteria etc. Biological washing powders help too. Here is an undated guide provided by Which? http://www.which.co.uk/reviews/washing-machines/article/washing-machine-temperature-guide

In a recent Convo we learned that some people don’t wash their sheets very often. I’m very glad that I was never expected to wear a suit at work, having heard that some do not have suits cleaned very often. Like John, I am not aware of many cases of infections spread by low temperature washing.

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Below is a Powerpoint presentation which reduces the evidence to a presentation which details transference by clothing etc. and is a pretty easy way to get up to speed in 39 slides.


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And just for laughs and to avoid any invalid washing moments

I have always been unhappy with bagged-salads and this article is a doozy.

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I am less than impressed by what is reported in the IFH articles but a relevant article in a proper scientific journal is cited:

Honisch et al. (2014) Journal of Applied Microbiology 117, 1787–1797. Impact of wash cycle time, temperature and detergent formulation on the hygiene effectiveness of domestic laundering.

Aims: Investigation of the effect of temperature and duration of the laundering process with and without activated oxygen bleach (AOB)- containing detergent on the hygienic effectiveness of laundering.
Methods and Results: Cotton test swatches were contaminated with Staphylococcus aureus, Enterococcus hirae, Pseudomonas aeruginosa, Candida albicans and Trichophyton mentagrophytes and were washed in a household washing machine using temperatures between 20 and 60°C and different wash cycle times. The logarithmic microbial reduction factor and cross-contamination (i.e. transfer from contaminated to sterile swatches) were used to indicate the hygienic effectiveness of the washing process. For all tested micro-organisms, the temperature needed for decontamination depended on washing time and detergent type. Hygiene effectiveness of laundering was enhanced by inclusion of AOB even at lowest temperatures, except for C. albicans, which was virtually unaffected by AOB. The use of AOB- containing detergents as well as high washing temperatures reduced cross- contamination to sterile swatches included in the load.
Conclusions: Depending on the type of organism, longer wash cycle times or the use of AOB-containing detergents can be used to enhance the hygiene effectiveness of laundering.
Significance and Impact of the Study: The study demonstrates that it is possible to compensate for the loss of hygiene effectiveness of laundering at lower temperatures using detergents with activated oxygen bleach or by extending the wash cycle time.

Conflict of Interest
This study was funded by Miele & Cie., LG Electronics
Deutschland GmbH, Bosch und Siemens Hausger€ate
GmbH, Electrolux Italia S.p.A. and Bauknecht Hausger€ate

My notes:
AOB – active oxygen bleach – is commonly sodium perborate and will be present in most laundry detergent powders and tablets.
Maybe low temperature washing is enough to remove the bugs with the dirt, especially if detergent with bleach is used – see the text that I have emboldened.

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Glad to oblige with bringing more information out.

You will appreciate that the normal human will be overloading the wash and the actual machine temperature can be all over the place, and will not compensate for water hardness, and skimp on the amount of detergent. I think heat is the only “variable” that is actually controllable by the manufacturer. And that is the one the EU have messed with.

You have to laugh otherwise you cry.

BTW test.de report that with washing powders you can get very reduced efficacy is the powder settles out. Well that is what I think they are saying. They were testing for colour but it makes you wonder about powders with AOB and perhaps this aspect should be looked at.
” XL-cartons against bags
In the Laundry room of the Institute 24 color detergent had to show whether they really are the specialists for Colorful. In the Test, 13 so-called compact powder in plastic bags against 11 powder in up to five kilos of heavy cardboard carton entered. The result: a bag of powder in the Test, the dirt experts. 11 of 13 Compact washing bottom line, well, five of them also colours well preserved. Only a single color Laundry detergent from the big box is a Compact competitive, and overall good. Of the other XL products, two means are eight satisfactory or sufficient, even defective.”

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Actually reading further the formulations are apparently different with the compacts having different compositions. Looks like they are the ones to buy – provided you are not going for hygiene wash.

Very interesting article and would form the detailed part of a CAwiki article

Powder with different formulations

Voluminous powders are manufactured according to the other, for the provider is often significantly cheaper recipes as a Compact in small packages. Your reputation to deliver much for little money, you will not meet. At best, a product in the bulk pack, the price-performance ratio with 10 cents per wash load. Three of the five test winner − all in a compact powder − clean, hardly more expensive: they cost 12 cents per wash load.

Everyday Laundry

In the laboratory, textiles piled up next to colorful Checks also a mountain of everyday Laundry. 57 households have used Shirts and towels in the test order within a week and dirty. After the subsequent wash by the testing Institute, the textiles go back again to everyday life. 15 times the Back and Forth is repeated. In between and at the end of five experts to examine, how well the different powder dirt. In addition, a measurement device determines, how strong the textiles after the wash Grays. In the case of four agents, the results are so unsightly, that the test of quality are judgements sufficient or deficient.

Colors without bleach

None of the tested products is not as a specialist for stains of any kind. That is a surprise. Color washing powder does not contain bleach. This protects the colors, but also splashes of red wine, tea, or dark fruit juices. Even more important is how strong the remedy for such stains. After all, no one wants to jettison a color favorite shirt, just because coffee is spilled on it. 7 500 spots have stamped the examiners in the laboratory individually on white cloth, pipette, or printed, and after Washing, signing off. The Palette ranged from roast juice over the curry sauce and oil to Make-up and Chocolate ice cream.

Effective against spots

Against persistent engine oil is also the best Colors to come though. The most Compact remove stains at 40 degrees but good. This testifies to the powerful combinations of grease-dissolving surfactants and dirt sticking enzymes. The two weakest Compact in the Test with the patch, however, is hardly better than most of the powder from the cardboard box.

Just a few gentle colors

On the duration of each washing means are colors pale appearance. The power of the chemistry involved in them. Some of the color detergent, however, the balancing act between powerful Cleaning and gentle care: you are good at it, to protect the colors. A further advantage of this medium: they contain Zellulasen. These are special enzymes that nibbles off protruding fibers. You smooth virtually through the Wash roughened fabric surfaces. The colors look so beautiful for longer. Most of the powders in the Test Colorful faster, pale look.

Three protect bad before Staining

Thus, in the washing machine no dyes from a piece of Laundry are transferred to another, the manufacturers of so-called dye transfer inhibitors. Almost all of the powder in the Test to protect the Textile good in front of the RUB off. Poor grades received in this discipline only three of the powder from the package: the test materials are stained.

Compact materials with better content

That Compact is usually cleaner than washing the powder out of the large boxes, of different chemical composition. In the Large are often cheaper, less effective ingredients or lower amounts of powerful active ingredients. This applies to surfactants, such as for enzymes. And also for the water softener: The best washing powder out of the bag soften water with a high proportion of zeolites. The are particularly effective, but quite expensive. Softener in powder from large packages is mostly carbonate, the less effective sodium.

Fillers without the washing effect

Up to half of the Laundry detergents consist of sulfate in the large cardboard boxes in addition of sodium. The salt is used for washing clothes. The filler is cost-effective. Its only function is to ensure that the powder remain dry, and better out of the measuring cups trickle.

Compact powders are the first choice

Compact powder from the bag, have the advantage that they per wash using less packaging material and fillers to get along than the in a carton. Two of the winner of the test cut, however, in the test point water pollution as the Only one in the Test is only satisfactory. The reason is they burden sewage treatment plants with slightly higher amounts of Surfactant. The environmental balance sheet of the XL-powder has improved over the decades. Today you will be in a lower dosage than 30 years ago. Instead of 200 grams and more per wash cycle provider recommended for you now 65 to 75 grams. Most of the Compact lie here approximately at the same level, but due to their higher density, less space in the measuring Cup.”

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Patrick, this is interesting, but what would be your summary of all this information?

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Ideally I would do Google and a Bing translations also before advising anyone.

However from the above I am now a convert to the compact offering as I thing test.de have made a very good case providing the science aswell as a recommendation.

From the point of view of hygienic washing I am very keen that reliable temperatures are used, and also the length of time taken at that heat. As mentioned humans and hard water and overloading, and even using the wrong powder will all weaken the hygienic factor and heat is the only one that can/should be relied on.

In the test slides the length of time for a longer wash did not address the problem of washing machines that very briefly reach the nominated temperature and then drop off rapidly.

This needs to be covered and I will write to IFH tomorrow asking about that. I do know that the Beko machines did keep a plus 55C temperature for much much longer than most, and of course some machines got nowhere near 60C in the 2013 trial.

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Do we just ignore the possibility that physical removal of bacteria could be more important than temperature (e.g. when comparing 40˚C and 60˚C) and the fact that 60˚C will not kill all the Gram positive bacteria? Any competent scientist would consider all the relevant factors rather than focusing on one.

Recalling the Which? report that tested the temperatures attained by different machines and the holding time at these temperatures. I would expect to see a variation between models and I wonder how many of each was tested. Without this information it is safest to assume that only one of each was tested.

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I am a little disappointed wavechange in your absolutist statements – and I certainly know increased rinses are very useful for removing bed mite debris and eggs.

I have collected all the data I can find aswell as what IFH have – and bear in mind I have been in correspondence with a University, the RCN, AllergyUK, Que Choisir, and the IFH over the last couple of years.

” fact that 60˚C will not kill all the Gram positive bacteria” All the evidence is expressed as LR log reduction and it is acknowledged nothing is 100%. It is all a matter of reduction of risk by reduction in the nasties.

Water for rinsing in some countries is more expensive than using hot water freely provided by the sun so the UK perspective of cheap water versus global emission saving does not — wash. : )

I am not phobic about germs etc etc but then I do not work in an environment where I ought to be very concerned.

I am concerned hat people who do work in environments were blood, soil, dirt and faeces etc are common that they are able to be confident in the wash provided by their machines. We must also consider sickness in the home when a hygienic wash is required.

People can control the powder, the pre-wash, the amount of clothing etc but if they believe they are doing a 60C wash and it is operating at a much lower temperature I think that is a deplorable situation.

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What I am trying to do is raise awareness of all the relevant information rather than just focusing on washing temperature. Using laundry detergent containing bleach, raising the temperature, increasing washing time and good rinsing all help to remove bacteria, dust mite faeces, etc. Good rinsing and not using excessive detergent are also important in removing detergent residue that could cause skin irritation. I did not mention rinsing above but it is relevant and something I have mentioned in earlier discussions.

Chlorine or oxygen bleaches are extremely effective at dealing with harmful bacteria. Products such as ‘Napisan’ are sold for use in washing machines. They will also help prevent the insides of machines from building up a coating of bacteria and moulds.

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So how does one check to establish that the real temperature of a washing machine is accurate and coincides with the temperature at which it is set on the programmer? My washing machine is almost antique by today’s standards, so my question is , has technology advanced enough for consumers to be able to determine the real temperature of the water washing the laundry?

On the question of bed bugs, they are very much alive and sucking in Londons top hotels, due mainly to the high proportion of foreign travellers transporting them in rucksacks and on their clothing and the little devils are becoming more resistant to treatment. More reading on this can be found at: http://www.standard.co.uk – London is being infested by super resistant bed bugs.

Warning: Anti-histamine cream at the ready before logging on!

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I could just imagine those “super bedbugs ” being a basis for a US blockbuster move showing millions of them crawling all over London stopping traffic eating people and The Lord Mayor calling for help from Will Smith +Jeff Goldblum of “Independence Day” -the movie who arrive with alien weapons to destroy them. I have warned that chemical sprays will get out of hand and affect the insect world.

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The simplest way to check the temperature is to use thermocouple (see Wikipedia) connected to a meter. The wire probe will pass through he door seal without leakage. This works OK if the machine is run empty but with a load present, the wire is likely to be broken by repeated bending. Nowadays there is no need to have an expensive temperature meter since some inexpensive multimeters can be used with thermocouples.

Laser thermometers are popular with hobbyists and it has been suggested that the temperature of a washing machine can be measured through the glass door. That does not work.

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I have a infra-red “gun” which cost around £13 and so I can point it at the water coming into the dtergent drawer – partially opened – at that shows 60C which is AFAIR a tad lower than my immersion heater setting.

Your machine Beryl will probably have a hot and cold feed and this is what speeds up the wash. Dual-fills have gone out of fashion and they are rare beasts. I have pointed out to Which? the lack of a dual-fill filter button when you want to see which ones of the 300+ machines reviewed offer it.

For single cold fill machines they use their heating element [ at the probable peak time rate] to heat the water. This takes time and energy and for some they barely make any attempt to get near the supposed temperature. Having said that Which? calculated the cost at around £32 a year compared to £24 for a 40C wash.

For people in those circumstances and without access to the right equipment my gun would give a reading from the glass cover. In the September 2013 magazine article they actually provided graphs for the temperature profile for various makes. Beko kept the high temperature the longest.



” Stand-out results
The washing machine that stayed warmest for longest was the Panasonic NA-147VB4, which maintained a temperature of around 60˚C for three minutes.
The Beko WM7043CW stood out as it kept the water around or above 55˚C for 30 minutes (see graph 2, above) – much longer than any other machine in our tests. Beko said this is for better cleaning and hygiene reasons and that all its washing machines follow a similar heating pattern. The second machine to produce surprising results was the Indesit IWD71251ECO, which consistently reached 67˚C (see graph 3, above). But Indesit said: ‘This is different than the temperature measured during our internal tests and has to be considered as abnormal’.”

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You have a wonderful imagination Duncan!

Why doesn’t someone invent a remedy to make super humans who are resistant to certain toxins? If it works with bugs why not us? Bordering on the futuristic, it could be the solution to replacing the antibiotic predicament.

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The temperature of the incoming water is not a useful indicator of the washing temperature. That’s not surprising because hot water will cool when it enters a cold machine. I confirmed this on my own machine back in the early 80s.

Measuring the temperature of the door glass with an infrared thermometer (often called a laser thermometer because a laser is used to show where it is pointing) is not very accurate but as Patrick says they are cheap and can be used to get an insight into what is happening.

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Thats what I was hinting at Beryl – too many chemical taken by both insects and humans , the first to destroy them –but only breeds “super bugs ” and the second for people to stop pestering their doctors for medicine for the common cold and closeting them in environments that buffer them from the outside world for years and then expect them to grow up resistant to disease and downgrading their DNA by a type of selective breeding that “hybridizes” them to be less than normal evolutionary human beings.

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@dieseltaylor Patrick – Perhaps we could look at the problem of contaminated washing machines. Thanks to the move to lower temperature washing and use of liquid and gel laundry detergents that don’t contain bleach, users are seeing evidence of microbial contamination of door seals and detergent drawers, and reporting foul smells from their machines. There are some reports that clothes smell after washing, suggesting contamination from bugs growing in the machine. It will not just be the door seals and detergent drawers that become contaminated.

The usual recommendation is to carry out a ‘maintenance wash’ at regular intervals, using a high temperature and a laundry detergent containing bleach. My own experience showed that washing once a week at 60˚C was sufficient to keep the inside of the machine clean but with modern machines that don’t reach this temperature, I suggest doing maintenance washes at the highest temperature available. Incidentally, I wonder if a 90 setting still means 90˚C.

It is quite clear that continued use of low temperature washing using gels or liquids allows bugs to grow in washing machines. I believe this could be a bigger issue than concern about bugs remaining on clothing after low temperature washing, but it depends on whether the bugs that grow inside washing machines are harmful or not.

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wavechange – You are right with your suspicion. Most cross-contamination events occur in sub-50C washes.

I am indebted to IFH for a glimpse at some articles that are probably available to you WC.

Impact of wash cycle time, temperature and detergent
formulation on the hygiene effectiveness of domestic
M. Honisch1, R. Stamminger1 and D.P. Bockm€uhl2
1 University of Bonn, Bonn, Germany
2 Rhine-Waal University of Applied Sciences, Kleve, Germany
activated oxygen bleach, domestic laundry,
laundry hygiene, wash cycle time, washing
process, washing temperature.
Dirk P. Bockm€uhl, Rhine-Waal University of
Applied Sciences, Marie-Curie-Strasse 1,
47533 Kleve, Germany.
E-mail: dirk.bockmuehl@hsrw.eu
2014/0930: received 7 May 2014, revised 5
September 2014 and accepted 5 September

y Britta Brands1, Angelina Brinkmann1, Sally Bloomfield2 and Dirk P. Bockmühl1
Microbicidal Action of Heat, Detergents and Active Oxygen Bleach as Components of Laundry Hygiene

They may mean more to you than to me as a layman but unlike the washing-machines reported by Which? in 2013 where we usefully saw the temperature graphs over time in these experiments the water temperature is high for the at the correct temperature for the time stated.

They machine was adapted by Miele for the purpose. We can therefore say confidently that all bar one of the machines Which? tested did not keep a high temperature for a suitable period.

Anyway see what you think. The formula remains that heat has an effect, AOB has an effect, and mechcanical action and rinses have an effect. : )

“For domestic laundering, hygiene effectiveness is important
against fungi as well as bacterial strains. In developed
countries, T. rubrum accounts for 70% of all dermatophytoses
(including athlete’s foot) in humans. Textiles (including
socks and stockings) in direct contact with affected
skin are major pathogen carriers and only a few viable
spores are required for skin infection (Hammer et al.
2010). For people with vaginal candidiasis, tight-fitting
garments may become contaminated and can cause reinfection
after successful therapy (Ossowski et al. 1999).
Although this systematic analysis of the impact of time,
temperature and detergent type has contributed valuable
information about the impact of these factors on the
hygiene effectiveness of laundering, it was only possible
to evaluate a single type of washing machine and two
defined detergents in this study. It is possible that other
machine parameters (such as mechanics, temperature
profile, water consumption and number of rinse cycles)
and other detergent formulations could also be exploited
to improve hygiene effectiveness at lower temperatures.
These aspects require further investigations.”

Note they have not considered mites,bedbugs etc in the testing regime.

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This is the paper I mentioned earlier, Patrick: https://conversation.which.co.uk/home-energy/washing-machines-60-degrees-kill-bugs-detergent/#comment-1466887 I have the full paper and posted the abstract, which will be in the public domain. I’m glad you have a copy and I will read it properly.

“The formula remains that heat has an effect, AOB has an effect, and mechcanical action and rinses have an effect. : )” Precisely. I’ve been wanting to take all factors into account, but one that has been overlooked is internal contamination of machines. What I’m trying to find is information about the bugs that grow in washing machines when they are not in use. I suspect that the numbers will be far greater than those left on fabrics after laundering. However, not all hazardous bacteria grow well outside the body. It would be interesting to know which species are typically found in machines.

Another consideration is short washes. My Miele machine does a 20 minute wash and I assume that other makes offer similar short washes. I have not tried it but subtracting the time for filling, rinses and spinning, the actual wash time will be very short indeed. If you are going to rely on mechanical cleaning and bug removal, long washing cycles are needed.

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Yes you did post that and perhaps I should have highlighted this one more from 2016 which seems to me the very natural extension of the 2014 piece.

Britta Brands1, Angelina Brinkmann1, Sally Bloomfield2 and Dirk P. Bockmühl1

Microbicidal Action of Heat, Detergents and Active Oxygen Bleach as Components of Laundry Hygiene

“5 Conclusions
Overall, the results of this study confirm that the microbici-
dal action of heat makes a significant contribution to the hy-
giene efficacy of laundering at 608C, producing 1 to 3 LR
when the temperature is maintained for at least 15 min. By
contrast, heat has little microbicidal effect at temperatures of
40 8C or below. Since laundry detergent without AOB ap-
pears to exert limited microbicidal action, this means that
hygiene efficacy at temperatures of 40 8C or less is almost
entirely dependent on removal of microbes during the wash
and rinse cycles.
One of the aims of this study was to see how, and to what
extent, it might be possible to compensate for the loss of hy-
giene efficacy at reduced laundering temperatures by enhan-
cing the microbicidal action of other components.
Although the detergent used in this study had some mi-
crobicidal action, the extent of this action appears to be lim-
ited, even at extended contact times up to 90 mins. Because
the lethal action was variable across test strains, it indicates
that use of detergent to compensate for loss of hygiene effi-
cacy associated with low temperature laundering is not a
feasible option. Since the detergent as used in this formula-
tion resembles current market products, it suggests that this
approach is not a worthwhile option to pursue.
By contrast the results suggest that, where detergents con-
taining AOB are used, the microbicidal action attributable to
AOB has the potential to compensate for the loss of efficacy
associated with low temperature laundering. Further work
would be worthwhile to understand the source of the incon-
sistencies between the suspension test and machine laun-
dering test data with T. mentagrophytes and C. albicans, and
to evaluate whether and how this might be addressed to en-
hance efficacy of AOB against C. albicans during machine
laundering at lower temperatures.
This study shows that increased contact times have little
or no effect on the microbicidal action of heat, detergent or
AOB, from which it is deduced that the increased LR values
observed by Honisch et al. [4] by extending the wash cycle
time from 15 to 90 min, are due to enhanced removal.
Further work is required to investigate how and to what ex-
tent detachment can be further increased by mechanical ac-
tion, including an increase of the number of rinse cycles.
Since some fabrics are not suited to laundering in AOB-con-
taining detergents, other options need to be explored to
meet the need for effective laundry hygiene at lower tem-

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This does not come up in Web of Science, the search tool that I use to look for scientific papers. That’s because it is not in a peer reviewed journal. I don’t have a copy of the article and have no insight into the experimental design or the basis of the authors’ conclusions, so cannot make any useful comment.

We have agreed that temperature, bleach, mechanical action and rinsing are factors in removing bugs. Obviously the length of the wash cycle will be important too. What I’m looking for is information about the contamination of washing loads by machines that have a biofilm of bacteria and fungi growing in them.

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I think I know what you are after Wavechange– Professor Sally F. Bloomfield/Professor Martin Exner/ Professor Carlo Signorelli-professor Kumar Jyoti Nath /DR Elizabeth A Scott — PDF on this very subject –highly detailed — http://europeantissue.com/wp-content/uploads/The-infection-risks-associated-with-clothing-and-household-linens.pdf— let me know if the URL doesn’t work I have put a link to it on my screen.

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Thanks Duncan. I realise that I have a copy of this (it’s a Word file, complete with annotations 🙁 ) on my desktop, downloaded from the IFH website. I’m disappointed that the authors have not published in a peer reviewed journal and have not stated the source of their funding. I will have a look at some of the references at the end of the document.

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Wavechange -have a look at -http://www.infectioncontroltoday.com/articles/2003/02/lessons-in-linen.aspx- scroll down to description of two types of hospital laundry cleaning temperatures and chemicals used. Dont know why its not a direct link ?

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That’s a strange article, obviously copied from another source without the references.

It’s no surprise that chlorine bleach is effective in combination with low temperature washing. We use it to disinfect reusable nappies, wipe kitchen surfaces and to sterilise babies’ bottles. Unfortunately it damages some fabrics and is no use with dark colours, and might not be compatible with the materials used in construction of washing machines.

Once again we see reference to a combination of methods used to remove bugs.