Can anyone recommend a mask to reduce the risk of contacting legionella? I have to visit low use water systems and flush them through on a regular basis. The routine is to walk around and turn all the taps on then go back to the start and turn them all off again. The highest risk being the return trip. Any advice on a suitable mask?

I would anticipate that the highest risk could well be at the start of the job, not at the end. Do remember that once you find the correct mask you have to wear it properly - often not the case - and since you may be placing others who are in the vicinity at as great a risk as yourself, and possibly greater, you need to think what you are going to do to protect them. And think also about flushing low-use taps. That just gives the little blighters some fresh food. There are more effective ways of getting rid of them and/or keeping number low, including removing those taps that are used infrequently!

Were did this come from, EN149:2001 FFP3 is a valved paper mask, same as used to stop dust on construction site. But I would agree that there must be a better way of ensuring that it is controlled in infrequent used locations

Serious questions? Anybody any idea of the number of legionella cases in the UK contracted from turning a tap on? And in your risk assessment the probability would be.........?

You guys get somewhat over-excited by Weil's Disease with less than 100 reported cases per annum nationally, and the incidence of Legionnaires (excluding imported cases) is slightly higher. Do take care not to be dismissive of this potentially fatal infection. I was in Court over a case referred to me recently, when a ventilation engineer working for a company that offered a full Legionella management service (air con, spa, shower heads, taps etc) contracted a particularly severe infection. He launched an action against the premises where he thought he contracted his infection but molecular strain typing disproved a link and the case was withdrawn. But as part of my pre-case investigation I interviewed the patient and noticed that he had been issued with the wrong masks by his employer. So the case went down that route, and he got his money after all! These infections do occur, though the epidemiological data are often lacking. Shortage of EHOs, a mismatch between geographic work areas with that of EHOs, that in turn are not co-terminus with the geographic work areas of HPA regions makes for poor quality case investigation and follow-up of cases, as in the case I mention. That does not lessen the severity of infection - this guy had 5 days in Intensive Care, 18 days in hospital and still has impaired respiratory function that is now unlikely ever to resolve - or the incidence of infection, much of which is put down to unresolved sporadic cases but which may well be occupational.

No answers then? I believe the risk to be minimal but am quite happy to be persuaded otherwise - if you have the evidence. A nice little earner though!

This thread is livelier than I expected. The risk assessment identified the need for a mask but I did not know what type so used the expertise on the forum to get information. The water sources are unused toilets, sinks and showers - all to be put back into service at some time when the offices are re-occupied. The shower head is bagged following the advice on a different thread. Thanks for you input. I will consider the occasionally conflicting advice, review the RA then make my choice.