Legionella Control

[franksonny]

Can anyone tell me the criteria for testing hot and cold outlets.

Is it hot water to reach min. 55 degrees within 1 minute and cold water no higher than 20 degrees ?

Thanks.

 

[Johnmelad502]

Can anyone tell me the criteria for testing hot and cold outlets.

Is it hot water to reach min. 55 degrees within 1 minute and cold water no higher than 20 degrees ?

Thanks.

In what context?

 

[franksonny]

In the context of legionella control criteria.

After a bit of research, I have found the answer.

The outlet at the cold water tap should be 20 degC after running for 2 minutes and the hot outlet should reach 50 degC within 1 minute.

Info is here if anyone is interested:

http://www.hse.gov.uk/pubns/priced/l8.pdf

 

[mysteryman]

The hot should be 60.

 

[Biggles..]

no, it should be above 50 at the outlet.

60 from primary supply,50 on return (if fitted)

read L8 if your struggling to understand

 

[glasgowgas]

to elaborate on LCG`s correct post

hot sentinel tap, after running for 1 minute should be between 50 and 60 deg C (anything under 50 is a legionella risk, above 60 is a scald risk)

 

[ianniann]

Thank you for bringing that up. Statistically, scald risk is far more danger than Legionella so don't get carried away with the temperature.

 

[Onetap]

Statistically, scald risk is far more danger than Legionella so don't get carried away with the temperature.

Strange!

The control of Legionella is covered by the Health & Safety at Work Acts so,if it's not an owner-occupied house,you have to follow L8; store at 60, 50degC within 1 minute from any hot tap and cold at less than 20. Records have to be maintained.

Put 'very hot water' signs up. If the users are 'at risk' (very young, very old or disabled) you need TMVs. The L8 temperature recommendations aren't negotiable.

 

[transam]

Recent research carried out by ?? (cannot remember ) suggests that one of the biggest risks to contracting legionella is widscreen washers on cars ????

 

[ianniann]

Far more people killed by scalding in the home than by Legionella from domestic hot water, and orders of magnitude more people injured by scalding.

I don't dispute your description of the regulations, but I'm encouraging you to step out from behind your box-ticking 'elf'n'safety mentality and appreciate the actual dangers. Note also that the HSE encourages the restriction of hot water outlets to 44C maximum in non-domestic premises where "vulnerable" people may have access.

Still, all small potatoes. By far the majority of scalding injuries occur in domestic premises. While continuing to check your boxes, please be aware that hot water is the bigger danger and where possible systems should be set to no more than the necessary storage temperature and that combis can be set lower in most circumstances.

Oh, by the way, you can call me a hypocrite if you like. I have my water temperature considerably warmer than 60C, but then nobody likely to be harmed has access to it

 

[Biggles..]

just so people are aware,the risk of scalding is now covered by the long awaited part g ammendment.(3.63 onwards)

http://dl.dropbox.com/u/3745388/part g draft.pdf

also worth a read is

http://dl.dropbox.com/u/3745388/TMV's Hot water scalding prevention.pdf

legionella and scalding have their own important documenation that should be read and understood.

Lee

 

[franksonny]

In addition then, if TMV's are fitted to all outlets and all hot water is mixed, how do you take a temperature reading when carrying out a legionella control programme?

Do you just take a non mixed outlet, such as a kitchen sink and utilise it as the sentinel tap, regardless of where it is positioned within the system?

 

[Biggles..]

No for legionella control you would measure and record all outlets,for tmv's you would use a surface temp guage to measure the hot into the valve.

 

[dreadnoughtheating]

Given that the symptoms of Legionella are often confused with 'influenza', an I do wonder if it is an 'under recorded' cause of death.

Also, Legionella needs to be be ingested (via a spray?) rather than swallowed to become an issue - hence the plethora of regs about AirCon coolers/communal showers/fountains in lobbies of buildings etc.

Just my take

DH

 

[Onetap]

I don't dispute your description of the regulations, but I'm encouraging you to step out from behind your box-ticking 'elf'n'safety mentality and appreciate the actual dangers. Note also that the HSE encourages the restriction of hot water outlets to 44C maximum in non-domestic premises where "vulnerable" people may have access.

I'm well aware of the dangers, I was doing nursing home building services design 25 years ago. You can comply with the L8 temperature regime regulations and achieve safe discharge temperatures with TMVs on all hot outlets. Problems arise when the reasons behind the temperature regime aren't understood, or the temperature monitoring is neglected.

I was saying years ago that windscreen washer bottles were a legionella breeding ground.