Page 10 - inPRINT Issue 63
P. 10


                   Legionnaires’ disease has an incubation
                   period of 2 to 10 days                  *

    environment  LEGIONELLA – REOPENING


               hen buildings reopen   Legionella risk factors
           Wafter lockdown, it     During the lockdown,
           is essential that water   there are two risk factors
           systems are not put     that may have increased,
           back into use without   creating ideal conditions
           considering the risks of   for Legionella bacteria to
           Legionnaires’ disease.   grow in your water system.
           There is an increased risk of   These are temperature and
           waterborne pathogens such   time for stagnation to occur.
           as Legionella bacteria being   Legionella bacteria thrive
           present in consequence   at temperatures between
           of the conditions that   20°C and 45°C, so one of the
           lockdown may have       key control measures for
           created. As a result of the   minimising the risk is to
           COVID-19 pandemic, there   ensure that your cold water
           is also the potential for   is cold (i.e. below 20°C) and
           an increased number of   the hot water is hot (above
           people to be susceptible   45°C).                 Actions to take before   Legal requirements
           to Legionnaires’ disease   When water is below 20°C   reopening:         and guidance
           due to a compromised    or above 45°C, Legionella   » Flush through simple hot/  Employers must manage
           respiratory system during   bacteria will not grow.   cold water systems with   the risks of exposure
           or after infection with   But water between these   fresh mains water for   to Legionella bacteria,
           COVID-19.               temperatures presents     several minutes        especially where buildings
            Legionnaires’ disease   a greater degree of risk,   » Increase the temperature   are closed, subject to
           is a type of pneumonia   particularly where it is left   of hot water systems to   low use or due to reopen.
           that can cause serious   to stagnate. Generally, if   above 60°C if possible   Guidance on how to do this
           respiratory illness. It can   water remains in a system   and draw it through   is provided in these (HSE)
           occur when tiny droplets of   without movement for more   to all hot water outlets   documents:
           water (aerosol) containing   than a week, the risk of   (a temperature over   L8 Approved Code of
           Legionella bacteria are   growth will increase.   60°C will kill Legionella   Practice and guidance on
           breathed into the lungs of                        bacteria over time)    Legionella regulations
           susceptible people, and   Control measures      » Flush through larger    HSG274 Part 2 – The
           is therefore very similar   For simple hot/cold water   hot/cold water systems   Control of Legionella
           to COVID-19. Preventing   systems, a review could   (including those with   Bacteria in Hot and Cold
           Legionnaires’ disease   be straightforward. The   tanks and showers) for a   Water Systems
           is typically achieved by   main objectives should be   significant period of time
           limiting the growth of   to prevent stagnation and   » Ensure the system is   For more information
           Legionella in building   keep water temperatures   capable of delivering   about Legionella, please
           water systems.          outside of 20-45°C. If    water at safe          contact Phil Ashcroft,
            Legionella bacteria will   possible, aim to ensure   temperatures by checking   HS&E Adviser, at
           inevitably enter man-   the turnover of any water   temperatures ahead of   [email protected]
           made water systems, but   stored in tanks every 24   reopening
           the degree of risk it poses   hours, and movement of   » Undertake a chemical   *
           will vary. All hot and cold   water through pipework and   disinfection of the water   room/fact-sheets/detail/
           water systems need to be   outlets at least once a week,   system        legionellosis
           considered, including those   to prevent it from becoming   » Undertake microbiological
           in hand washing facilities   stagnant.            sampling for Legionella
           and shower units.                                 bacteria

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