Welcome Guest! The IOSH forums are a free resource to both members and non-members. Login or register to use them

Postings made by forum users are personal opinions. IOSH is not responsible for the content or accuracy of any of the information contained in forum postings. Please carefully consider any advice you receive.

Notification

Icon
Error

Options
Go to last post Go to first unread
roshqse  
#1 Posted : 05 November 2012 11:10:25(UTC)
Rank: Forum user
roshqse

About to carry out a RA for legionella and just had a thought. (Dangerous I know!) Although we have no appreciable risk on the premises, (no cooling systems, no sprays, hot water above 60'c etc.) we do use high pressure washers off site. These are normally connected to mains water systems but do occasionally use water bowsers. Is there an appreciable risk of legionalla with this equipment? The water is heated to above 60 degrees in operation, the operators wear full waterproofs , gloves and full face masks but we cannot guarantee the cleanliness of the water bowsers, which are hired in when required. What's your thoughts? Am I being over concerned or is there a real risk?
Nidan  
#2 Posted : 05 November 2012 14:17:04(UTC)
Rank: Forum user
Nidan

This is my opinion (and only my opinion)... I take it the equipment is emptied of water at the end of each working day? If so I would suggest (my opinion!) that Legionella is not a problem. Ready to be corrected...
roshqse  
#3 Posted : 05 November 2012 14:49:29(UTC)
Rank: Forum user
roshqse

That was my initial thoughts too.. then I thought 'hang on'. They water supply is often from static water bowsers. My concern is the possibility of standing water in these not being flushed or cleaned.
colinreeves  
#4 Posted : 05 November 2012 15:11:20(UTC)
Rank: Super forum user
colinreeves

From memory, and confirmed looking at the HSE site, the bacteria can only flourish in water from 10-45 degrees C. If your pressure washer is only used at 60 degrees then any bacteria will be unable to survive. If, on the other hand, you also use a cold wash then there is a possibility.
roshqse  
#5 Posted : 05 November 2012 15:34:02(UTC)
Rank: Forum user
roshqse

Having discussed the work with the operatives it's been confirmed that it is always operated at above 60 degrees. I think I am going to issue a training bulletin stating that bowsers should be flushed before hand , washers always operated above 80 degrees and face masks worn on every activity. Thanks for your input folks.
Jake  
#6 Posted : 05 November 2012 15:50:16(UTC)
Rank: Super forum user
Jake

I'm not a fan of Legionella management (how many instances have been causes by the scenario in question? Any at all?) but technically speaking the bacteria could develop in the bowsers - you have no idea what temperature and for how long the water has been held there. So the water could have the bacteria. It would then depend on the process as to whether there is actually a risk. Presumably upon jet washer start-up the water isn't immediately ejected at your set temperature? (i.e. the machine would have to get up to temperature?), there could be (albeit very small) risk of bacteria release at this point. From memory a temperature around 60 degrees C does kill bacteria, but takes a few minutes, but 70 degrees plus is effective at instantly killing the bacteria. A face mask may help, but would need to protect against breathing in the steam (if this is a control measure you require). I guess there may also be a very small risk that the pressure washer it's self isn't "clean" so a suitable mask would be recommended in any case.
roshqse  
#7 Posted : 05 November 2012 16:08:33(UTC)
Rank: Forum user
roshqse

You've pretty much summed my feelings Jake! You're correct that the machines do take a few moments to reach the requested temperatures. Operating at 80 degrees and above will in my assessment and understanding kill bacteria instantly, the risk being presented for a very short period during warm up. The bowsers are the main problem as far as I can see because we have little control over them. They are hired in as required. I think it's a matter of training, PPE and control measures such as draining and flushing systems before use. Thanks everyone.
mikethoms  
#8 Posted : 11 August 2017 08:39:48(UTC)
Rank: New forum user
mikethoms

As per discussion, i realized that all of you are experts, having good piece of knowledge on best pressure washers and cleaning services, due to relevancy i don’t want to make a separate post for my question. What do you guys recommend me if i want to buy new and best pressure washer for home use? Is it wise decision to buy or should continue with pressure cleaning services? Wink

chris.packham  
#9 Posted : 11 August 2017 11:35:33(UTC)
Rank: Super forum user
chris.packham

A stupid question, perhaps, but trying to keep things in perspective.

Does anyone have any statistics on the number of cases of legionella that have been recorded arising from (domestic) use of a pressure washer?

Chris

Ian A-H  
#10 Posted : 11 August 2017 15:42:20(UTC)
Rank: Forum user
Ian  A-H

I would say the risk is very low. Once the heater kicks in the water is heated to a tempeature that will kill the bacteria, so there is a small risk in the first few seconds of operation. Also there may be residual (stagnant) water in the jet washer hose.

How about during the first minute or so of operation the jet is directed into the ground or a drain? (Provided the water has reached operating temperature during this time.) Once this is done the risk is negligible.

Ron Hunter  
#11 Posted : 11 August 2017 17:02:43(UTC)
Rank: Super forum user
Ron Hunter

All in all, I think I'm probably at as much risk every time I flush the toilet.

johnmurray  
#12 Posted : 11 August 2017 18:48:48(UTC)
Rank: Super forum user
johnmurray

thanks 1 user thanked johnmurray for this useful post.
JohnW on 13/08/2017(UTC)
mikethoms  
#13 Posted : 20 August 2017 10:49:46(UTC)
Rank: New forum user
mikethoms

As per thread discussion, i realized that all of you have good piece of knowledge on best pressure washers and cleaning services, due to relevancy i don’t want to make a separate post for my question. What do you guys recommend me if i want to buy new and best pressure washer for home use? Is it wise decision to buy or should continue with pressure cleaning services?

mikethoms  
#14 Posted : 20 August 2017 11:01:46(UTC)
Rank: New forum user
mikethoms

+ i'm lookng forward to know if pressure washer reviews on internet are valid to take final decision?

mikethoms  
#15 Posted : 21 August 2017 05:02:23(UTC)
Rank: New forum user
mikethoms

+ i'm lookng forward to know if pressure washer reviews on internet are valid to take final decision?

johnmurray  
#16 Posted : 21 August 2017 08:53:23(UTC)
Rank: Super forum user
johnmurray

Originally Posted by: mikethoms Go to Quoted Post
+ i'm lookng forward to know ifpressure washer reviewson internet are valid to take final decision?
Up to you! This topic is about legionella spread by use of infected water in pressure washers/steam cleaners. If it is attached to a mains-water outlet it is hardly an issue, as long as the cleaner has clean water in it from the outset! Type/maker/colour/power-source are commercial choices!
Users browsing this topic
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.