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Kia Ora all
I am trying to find, with not much success, information on the likliehood (or otherwise) of legionella exposure when servicing fire sprinkler systems.
My limited knowledge suggetss that this is a likely risk, but our fire engineers "have never heard of such a thing"".
I would be obliged if anyone can point me in the direction of any research material/resources which I can review.
Many thanks
Gary
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Sprinkler systems are pressure systems, not open to atmosphere or accessible to foreign bodies. Is it possible for legionella to develop?
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Yes, a recent HSE document (http://www.hse.gov.uk/aboutus/meetings/hseboard/2013/300113/pjanb1309.pdf) mentions that fire sprinkler systems have the potential to create a risk from Legionella. A Fire Industry Association guidance document I came across (Guidance on Legionella in Fire Fighting Systems and Equipment FIA Guidance for the Fire Protection Industry) contains some good general guidance in relation to sprinkler systems and may provide you Gary with some information on what you are looking at currently. There is also some further information out there in relation to fire sprinkler systems and Legionella, but effectively they all say the same thing in that the risk of exposure and contracting Legionella (once risk assessed and the necessary control measures undertaken) is realitively low. Of course it will vary from system to system, but hopefully the above information will help you in what you are looking at.
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It must be such that anything and everything [car windscreen water systems?] may have the risk where the circumstances can come together that allows the bacteria to survive and multiply
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Ubiquitous bacteria, stagnant water, plenty of nutrients, variable temperatures that all add up to ideal breeding conditions.
But, is anyone aware of any reports of infection from sprinkler systems?
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David Bannister wrote:Ubiquitous bacteria, stagnant water, plenty of nutrients, variable temperatures that all add up to ideal breeding conditions.
But, is anyone aware of any reports of infection from sprinkler systems?
Never come across it myself and have had feet in both camps (active fire suppression systems / H+S).
Sprinklers are not like the depictions you see in films. Only the heads above the fire will activate so if you are being doused by sprinkler water, you are probably also in the middle of a fire.
Routine testing shouldn't produce exposure either since you are opening up a 1" test line to full flow. Insurance and maintenance testing even less so since that is a 4" main going full bore, straight to a drain.
This thread did start me thinking about dust suppression systems in the waste industry - fine water spray with pipework left out in the baking sun to reach a suitable temperature. If the system is not run for a few days, do you have a suitable breeding ground?
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Stevie have you never heard of a sprinkler head being damaged by maintenance man?
I have.
Further - sprinkler systems are being installed into private residential houses now, I wonder if this increases the risk to householders who may decide to DIY sprinkler maintenance themselves ?
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Gary
In a previous life I was the Health and Safety Adviser for one of the main companies that designed and manufactured sprinkler systems.
The sprinkler test cell was an area where new sprinkler heads were tested, this involved spraying a known volume of water through pipework and across a bucket covered floor. The test was observed by our technicians and then the water volumes in each bucket (and hence the spray pattern) was established. It was, as you might imagine, a very damp atmosphere.
At one point in time one of our technicians contracted a legionella type infection, described at the time as an "unusual strain of pneumonia". It was the doctors opinion that the infection was most likely caused by exposure to the water spray.
The pipes would lie over the weekend etc with some water residues in them and it was considered that this was the source
So I would say that a legionella type infection is feasible when working with sprinklers.
Hope this helps
Stuart
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I find it interesting to see an innocent question that seems so simple at the start develop into a much broader area of discussion.
It just shown the power of this forum in educating the users.
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I think others have clearly demonstrated that exposure to aerosol is possible. Degree of exposure is the key thing really. Legionella can usually get into a closed system if mains water or otherwise non-sterile water is used to fill or top up. Proliferation potential follows from that point.
HSG274 Part 3 covers other risk systems including fire suppression but only goes so far as to say that exposure should be minimised during witnessing of tests or blow-down of sprinklers. Clearly flushing is not a reasonable control measure! ;) Servicing is not covered but one would imagine that a similar approach would be warranted. Stevie40 seems to suggest that usual testing shouldn't lead to a particular aerosol generation but each system on its own merits?
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Oh, and yes, dust suppression systems sitting around unused in warm conditions would potentially be a pretty good breeding ground and a weapon of mass transmission!
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Thanks all for feedback so far.
My thinking.
pipework is internal to building structure and hence sits at a nice stable temperaure for bacteria to multiply.
The entire system is in effect a dead-leg under pressure.
My opinion is that the prescence of legionella bactreia is probable.
Maintenance activities often mean draining down a leg of the system. Observations of this activity are that an aerosol is created (in most cases for a short time only).
and we are a large public hospital.
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Gary, mention of a hospital triggered a memory of hearing about a legionella outbreak at a hospital traced back to the discharge of a fire hosereel through an upper floor window creating a mist that entered an open ward window and eventually led to a fatal outcome for a frail patient.
I have no further details but should be relatively easy to track down on t'internet.
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Firesafety101 - realised after I'd posted that I'd forgotten to mention impact damage. Never seen it happen but have seen the aftermath with the dirty water everywhere. Amazing how much the pipe branch network can hold even once you've turned off at the stop valve.
Nobody hung around beneath the deluge but you are right, there could be some exposure if say an FLT driver was trapped beneath a collapsed racking system with inrack protection compromised.
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Xavier123 wrote:Oh, and yes, dust suppression systems sitting around unused in warm conditions would potentially be a pretty good breeding ground and a weapon of mass transmission!
Indeed. I work with street/utility workers and their training/awareness/toolboxtalk includes guidance on use of water for Stihl Saw dust suppression. They have large 25L bottles of water on the back of their trucks, not used every day, which could breed legionella.
Suppressing dust on Stihl saws is necessary because of cement dust. When using them the operator is bent over the cutting area. The water suppression creates a mist of water. Another good reason to wear RPE and they are advised to change the water in the bottles every day.
JohnW
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John, HSE advise water suppression is not enough and should also wear RPE.
Silica is probably just as harmful as Legionella although takes longer to kill.
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FireSafety101 wrote:John, HSE advise water suppression is not enough and should also wear RPE.
Yes I was implying there that the saw users always wear rpe (FFP3) for the dust, and that another good reason is to avoid inhaling the water mist.
John
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Oh and I explain the reason to wear rpe AND to use water suppression is to also protect the public from the dust!
John
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Hmmmm water suppression is an effort to avoid creating dust in the first place, RPE is worn in case harmful silica particles are airborne.
Do you suggest members of the public should be wearing RPE as well as the operatives?
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FireSafety101 wrote: Hmmmm water suppression is an effort to avoid creating dust in the first place, RPE is worn in case harmful silica particles are airborne.
That's what I said FS.
FireSafety101 wrote:Do you suggest members of the public should be wearing RPE as well as the operatives?
No, because the water suppression is reducing the risk to the public.
FS, I don't think you have followed the thread well. I'll let you get back to your sprinklers :o/
John
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stevie40 wrote:
Sprinklers are not like the depictions you see in films. Only the heads above the fire will activate so if you are being doused by sprinkler water, you are probably also in the middle of a fire.
some systems are like those in the movies were they have a hammer system so if one head activates all the others in the area smash as well or you can manually activate all the heads by pressing a button
also there are flood systems which have no alcohol heads you turn a tap manually again spraying the whole area
then there are pressurised bag and ballon etc
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Got a link to those systems Psycho? Last involved with sprinklers in 2008 and I do not recall any such system at that time other than old water deluge systems for protecting listed structures - e.g. the Stone Bow in Lincoln.
How do these systems maintain water pressure? how many heads activating at once?
Thanks
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Physo - What is a pressurised bag and balloon in terms of a suppression system???
As for avoiding Legionella, we have an extensive pre-action water mist system, which as it is normally dry, get's around much of the preventative maintenance re waterbourne nasties
The same can be said for our boreholes which supply the water mist system and the building's grey water supplies, as that takes a lot of looking after.
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mssy wrote:Physo - What is a pressurised bag and balloon in terms of a suppression system???
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Pressurised Bag and balloon is a system that is usally used offshore in shipping
what you have is a pressurised bag or balloon which puts a presure on the fresh water up to the spray head the ballon is in a cylinder which contains fresh water
once the the head ruptures this back pressure from the balloon then runs the system until the fire main is run up to provide the secondary water supply,
which on a ship is usally salt water also the time for the firemain to activate may be 20-30 seconds , the initial fresh water also prevents corrosion in the pipes as the salt water back up usally causes the pipework to rot also the salt deposites can cause the heads to block up so the sprays do not activate so efficiently
a use for a hammer system would be in an area you may decide to flood, Due to a risk of explosion
so if you have an area on a ship for example and there is a fire in the same room or adjacent and what ever is in that room is over heating you hit manual which makes all the heads activate at once to flood the compartment or if you are carring cargo which is highly explosive you set to automatic so all the heads activate at the same time, a drop in pressure causes the hammer to smash all the other heads or if you have mixed low leval cargo you just set the system to normal use and single heads to activate
maintenance for the above
Daily check for leaks and the pressure at ballon , cylinder is at the required bar leval
Weekly, Release pressure in main line to check that alarms go off
Monthly Top up as required
6 monthly full drain of system,
Flood systems used on Paratecnic lockers were the distress flares can get so hot they can melt through a deck, Lockers flooded for cooling down , usally sighted high up on a ship so loads of decks to mealt through
smoke lockers no floods at all as smoke flaires are usally salt/water activated, again high up on ship away from doors so activation does not go into ship
then there is the totally specialised systems of
Bromochlorodifluoromethane still legal on some ships were the pipework has a back up of CO2 and a third back up of Salt Water used in main machinery spaces etc etc
Then Novac systems etc
Hope this helps
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Why not read the LPC Rules for Sprinkler installations 'Legionella and fire fighting systems' published by the Fire Protection Association
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Hedgehog wrote:Why not read the LPC Rules for Sprinkler installations 'Legionella and fire fighting systems' published by the Fire Protection Association
Yup, read that.
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