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Bazzer  
#1 Posted : 28 May 2021 15:47:39(UTC)
Rank: Forum user
Bazzer

I have completed a legionella risk assessment of the hot and cold water systems in an office. The hot water from the boiler is at 70 degC, balance valves fitted in the system are set to open at this temperature to increase water temperature in other parts of the system and to disnfect the system to reduce legionella risk. The wash hand basins are fitted with TMV's to give water at 44 degC. One problem is that the water from the kitchen sink standard mixer taps is at 70 degC, creating a significant scald risk; fitting a TMV would recuce the temperature to 44 which isn't really hot enough to remove grease. Any suggestions other than ' caution very hot water' signs.

chris.packham  
#2 Posted : 28 May 2021 16:20:09(UTC)
Rank: Super forum user
chris.packham

For hand washing the optimum temperature is between 32 and 38 deg C. Anything over 38 deg C should be considered as harmful to the skin. If you need more on this PM me with an e-mail address and I will send you an explanation with supporting data.

thanks 1 user thanked chris.packham for this useful post.
Bazzer on 28/05/2021(UTC)
Kate  
#3 Posted : 01 June 2021 06:58:05(UTC)
Rank: Super forum user
Kate

If you sometimes need warm water and sometimes need very hot water isn't the answer to have a mixer tap on which the user can adjust the mix just like they would be able to in their own home?

Bazzer  
#4 Posted : 01 June 2021 08:11:43(UTC)
Rank: Forum user
Bazzer

Yes youre right Kate, and it is a manual mixer tap like at home, but my concern is that the hot water temperature of 70 deg C is really too high in the workplace, and this poses a scald risk, and would rather have an automatic mixer that gioves water at 60 or less as lng as it is hot enough to remove grease.

chris.packham  
#5 Posted : 01 June 2021 08:19:02(UTC)
Rank: Super forum user
chris.packham

Kate,

When Berardesca and colleagues published their study on water temperature and the skin way back in 1998 I was involved in a project working with a skin specialist in Sweden. We visited a number of occupational physicians and asked them whether they could set their water at a temperature of just 40 deg C. In every case the temperature they set was well in excess. Relying on users to set the correct temperature is simply not a practical approach, hence my view that the TMV is an essential element in any hand washing facility.

hopeful  
#6 Posted : 01 June 2021 09:26:11(UTC)
Rank: Super forum user
hopeful

If the tap that you refer to is the wash hand basin in the kitchen then a TMV is acceptable. However in the washing sink there is less risk of scalding and you will be in conflict of Food Safety Regulations as the water needs to be hotter to sanitise equipment as well wash off grease. Generally people using these sinks are not vulnerable so the risk is less than in a public area where you do not know who is using the facility. Also through training they will understand the way to use the sink and they will also be used to using it, not strangers.

jodieclark1510  
#7 Posted : 03 June 2021 11:00:48(UTC)
Rank: Super forum user
jodieclark1510

Can the boiler or balance valves not be adjusted down at all?  How much stored water is there and what is the turnover like?

chris.packham  
#8 Posted : 03 June 2021 12:34:49(UTC)
Rank: Super forum user
chris.packham

Just a question . . . How hot does water have to be to 'sanitise' equipment in the sense of inactivating or killing potentially harmful microorganisms? I think you will find you would not wish to have your hands in water at this temperature for any length of time.

thanks 2 users thanked chris.packham for this useful post.
RVThompson on 03/06/2021(UTC), Dazzling Puddock on 03/06/2021(UTC)
Dazzling Puddock  
#9 Posted : 03 June 2021 15:04:07(UTC)
Rank: Forum user
Dazzling Puddock

There will be many things in a kitchen that are much hotter than 70 degrees C so the temperature should not be a major issue.

A pot wash sink is exactly that and should never be used as a whb, most KPs would wear gloves to protect the hands from hot water!

If you are not cleaning large pots and pans then get a dishwasher and forget about the issue altogether!

chris.packham  
#10 Posted : 04 June 2021 10:15:51(UTC)
Rank: Super forum user
chris.packham

Some years ago I had a request for help from a large kitchen in a teaching hospital. They had a dishwashing system for general crockery and cutlery, but large pots and pans were hand washed in sinks using very hot water. Those working in the area took it in turns to do the hand washing, each spending a day at this wearing thick, very long rubber gloves. On removing the gloves at the end of the day it was common to find layers of skin peeling of as a result of the extreme hyperhydration of the outermost layers of the skin (stratum corneum). If you are interested in how this was resolved PM me with contact details.

thanks 2 users thanked chris.packham for this useful post.
peter gotch on 04/06/2021(UTC), aud on 09/06/2021(UTC)
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