legionella control in the university of sheffield legionella awareness for departmental...
TRANSCRIPT
What is Legionella?A naturally occurring
bacteriumFound in most water
systemsOften present in mains
water Easily colonises most
domestic water systems – hot and cold
Requirements for Growth?
Optimum temperature range of 20 - 45 ⁰C
Food source (other bacteria & sediments)
Prefers stagnant conditions
Route of Infection?Primarily through inhalation of
aerosols, fine droplets & mistsCan be contracted by choking
on contaminated water Statistically most susceptible
- 50 to 70 year olds- Males- Smokers
How big a risk?
Legionnaire’s DiseasePotentially fatal form of pneumonia –
5-30% fatality rate
200-300 cases of infection in England & Wales annually
Incubation period 2-10 days - typically 3-6days
Legionella pneumophila – 23 sub typesHSE view Legionnaire's Disease as
“preventable” assuming management failure!
LegislationThe Health and Safety at
Work etc Act 1974Management of Health
& Safety at Work Regulations 1999
COSHH 2002 ACOP L8 (see front
cover)
L8 Guide to Successful ControlRequires: Management regime in placeRisk AssessmentsControl regimeMaintenance and upgradeReview
Risk Assessments should:Identify & quantify relevant wet systems plus
equipment holding / circulating waterAssess potential for Legionella growthIdentify who is at riskAssess the potential for bacterial transferQuantify and prioritise the risksDetermine suitable means of control
UoS Responsibilities 1Statutory Duty Holder who is ultimately
responsible – Registrar & SecretaryAppointed Responsible Person for day to day
management – Director of EstatesDeputy Responsible Person to cover holidays
and illness – Head of Engineering OperationsResponsibility cannot be delegated
UoS Responsibilities 2Policy for the Control of Legionella bacteriaManagement structure in place with
Contractors charged with carrying out: -Legionella Risk assessments of all buildingsTreatment of water assets where requiredSampling and analysis of water systemsRemedial works incl. removing “dead-legs”
5 Zones - Engineers managing Contractors
Current PositionCurrent regime in place for > 2 years95% buildings assessed (some low risk o/s)Current costs ~ £250,000 paMonitoring of sample results on-line Legionella Procedures Manual in placeLegionella Control Steering Group – 3 meetings
per year chaired by Prof R F JacksonPolicy and Procedures on Safety Services website
Typical Systems at RiskCooling TowersDomestic hot & cold water systemsWater features incl. ornamental fountainsEquipment producing aerosols, mists or
droplets from stored water sources including showers & humidifiers
Equipment holding / circulating water at 20 - 45⁰ C
Examples of lab & workshop equipmentWater tanks & bathsSpray tapsWater recirculation systems for coolingRarely used taps & showers (even at home)Misting equipmentDentistry toolsOil / water emulsions for lubricating lathesMobile AC equipment with water
Controlling Legionella bacteriaTemperature monitoringControlled release of water sprayAvoid temp. conditions 20 - 45⁰ CAvoid water stagnation - empty & clean regularlyAvoid materials which harbour bacteriaMaintain cleanliness of spray outletsWater treatment where necessaryEnsure correct & safe operation of systemFlushing regime for rarely-used outlets
What Departments need to do - 1Identify a Nominated Person to help you
manage Legionella risks in your DepartmentIdentify & record all : -
water-containing equipment which operates in the temperature range 20-45⁰C
all rarely-used taps & showersall equipment supplied from stored water
sources producing sprays, mists or aerosolsAssess the risk of Legionella growth in each
What Departments need to do - 2Check Legionella Procedures Manual for
information of the management of specific items of laboratory equipment
If your equipment is not listed, determine the best means of reducing Legionella risks – if needed, contact Department of Estates for help
Consider which treatment options are the most appropriate from the next slide
Treatment / remedial optionsMonitor temperatures; 20-45⁰C = risk rangeEvery 2 weeks - heat water to 60⁰C for 5 minsAdd disinfectants / Chloros as advisedEmpty out the water system, thoroughly clean
& refill with fresh water every monthClean & disinfect spray heads every monthFlush rarely-used outlets weeklyArrange with Estates for removal of “dead-legs” Arrange with Estates for samples to be taken if
risk exists (sampling is NOT a control measure – it takes 10 days for results to be sent through – it monitors whether your controls work)
Next stepRecord all actions taken and
results received.Review the efficacy of the
treatment regime by checking the results of analyses received
Re-assess the risk assessment if there are any changes to the operating parameters or the system layout
Drinking water coolers2 types generally available:
Using large bottles of mineral waterPlumbed-in units
Legionella is not reported to be a problem with water bottle coolers, usually work outside “critical temperature range”,
1 reported instance of Legionella bacteria being isolated from Activated Carbon filters in a plumbed-in unit in New Zealand – replace as recommended by manufacturer.
We hope you found this information useful!