Transcript Legionella control

Legionella control in the
University of Sheffield
Legionella Awareness for
Departmental representatives
What is Legionella?
 A naturally occurring
bacterium
 Found in most water
systems
 Often 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 &
mists
 Can be contracted by choking
on contaminated water
 Statistically most susceptible
- 50 to 70 year olds
- Males
- Smokers
How big a risk?
Legionnaire’s Disease
 Potentially 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 types
 HSE view Legionnaire's Disease as
“preventable” assuming management
failure!
Legionnaire's Disease
Legislation
 The Health and Safety at
Work etc Act 1974
 Management of Health &
Safety at Work
Regulations 1999
 COSHH 2002
 ACOP L8 (see front
cover)
L8 Guide to Successful Control
Requires:
Management regime in place
Risk Assessments
Control regime
Maintenance and upgrade
Review
Risk Assessments should:
 Identify & quantify relevant wet systems plus
equipment holding / circulating water
 Assess potential for Legionella growth
 Identify who is at risk
 Assess the potential for bacterial transfer
 Quantify and prioritise the risks
 Determine suitable means of control
UoS Responsibilities 1
 Statutory Duty Holder who is ultimately
responsible – Registrar & Secretary
 Appointed Responsible Person for day to day
management – Director of Estates
 Deputy Responsible Person to cover holidays
and illness – Head of Engineering Operations
 Responsibility cannot be delegated
UoS Responsibilities 2
 Policy for the Control of Legionella bacteria
 Management structure in place with
Contractors charged with carrying out:  Legionella Risk assessments of all buildings
 Treatment of water assets where required
 Sampling and analysis of water systems
 Remedial works incl. removing “dead-legs”
 5 Zones - Engineers managing Contractors
Current Position
 Current regime in place for > 2 years
 95% buildings assessed (some low risk o/s)
 Current costs ~ £250,000 pa
 Monitoring of sample results on-line
 Legionella Procedures Manual in place
 Legionella Control Steering Group – 3 meetings
per year chaired by Prof R F Jackson
 Policy and Procedures on Safety Services
website
Typical Systems at Risk
 Cooling Towers
 Domestic hot & cold water systems
 Water features incl. ornamental fountains
 Equipment producing aerosols, mists or
droplets from stored water sources including
showers & humidifiers
 Equipment holding / circulating
water at 20 - 45⁰ C
Examples of lab & workshop equipment
 Water tanks & baths
 Spray taps
 Water recirculation systems for cooling
 Rarely used taps & showers (even at home)
 Misting equipment
 Dentistry tools
 Oil / water emulsions for
lubricating lathes
 Mobile AC equipment with water
Controlling Legionella bacteria
 Temperature monitoring
 Controlled release of water spray
 Avoid temp. conditions 20 - 45⁰ C
 Avoid water stagnation - empty & clean regularly
 Avoid materials which harbour bacteria
 Maintain cleanliness of spray outlets
 Water treatment where necessary
 Ensure correct & safe operation of system
 Flushing regime for rarely-used outlets
What Departments need to do - 1
 Identify a Nominated Person to help you
manage Legionella risks in your Department
 Identify & record all :  water-containing equipment which
operates in the temperature range 20-45⁰C
 all rarely-used taps & showers
 all equipment supplied from stored water
sources producing sprays, mists or aerosols
 Assess the risk of Legionella growth in each
What Departments need to do - 2
 Check 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 options
 Monitor temperatures; 20-45⁰C = risk range
 Every 2 weeks - heat water to 60⁰C for 5 mins
 Add disinfectants / Chloros as advised
 Empty out the water system, thoroughly clean
& refill with fresh water every month
 Clean & disinfect spray heads every month
 Flush rarely-used outlets weekly
 Arrange 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 step
 Record 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 coolers
 2 types generally available:
 Using large bottles of mineral water
 Plumbed-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!