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FEDECAI Conference

FEDECAI Conference. Legionella – A British Perspective Presented by David Handley of Healthy Buildings International On 24th October 2002 in Valencia. What is Legionnaires ’ Disease ?. Potentially fatal form of pneumonia Affects anybody, but some individuals are particularly susceptible

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FEDECAI Conference

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  1. FEDECAI Conference Legionella – A British Perspective Presented by David Handley of Healthy Buildings International On 24th October 2002 in Valencia

  2. What is Legionnaires’ Disease ? • Potentially fatal form of pneumonia • Affects anybody, but some individuals are particularly susceptible • Contracted by inhalation of legionella bacteria from contaminated water • High fever, chills, headache & muscular pain • 200 –250 reported cases each year • Fatal in approximately 12% of cases • Legionellosis – range of illnesses cased by legionella bacteria

  3. What are Legionella? • Types of bacteria • Found in water at temperatures 6°C to 55°C • Requires nutrients to multiply • 40 different types of legionella • Legionella pneumophila – 16 serogroups • Legionella pneumophila sg1 is the causative bacterium for 90% of Legionnaires’ Disease

  4. Where are legionella found? • Found in environmental water sources • Colonises manufactured water systems • Cooling towers • Hot and cold water systems • Air handling plant • Other plant that uses or stores water

  5. History of Legionnaires’ Disease • 1976 Philadelphia • Clinical samples pre 1930 • 1985 Staffordshire Hospital • 1986 BBC London • 2002 Barrow-in Furness

  6. Legionella - Legislation • Health and Safety at Work Act 1988 • The Control of Substances Hazardous to Health 1994 (COSHH) • Approved Code of Practice (ACoP L8) • Launched 8th January 2001 • Replaced HS(G) 70, ACoP L8 (Rev) & MISC 150

  7. Requirements of the ACoP • Identify & Assess Sources of Risk • Prepare a Scheme for Preventing or Controlling the Risk • Implement & Manage the Precautions • Keep Records of the Precautions Implemented • Appoint a Person to be Managerially Responsible

  8. Changes in the New ACoP (1) • A New Title • Legionnaires’ Disease, The Control of Legionella Bacteria in Water Systems • Previously • The prevention or control of legionellosis (including legionnaires’ disease) • Aim • to directly identify the subject matter and avoid confusion

  9. Changes in the New ACoP (2) • The New ACoP is Split (Part 1 and Part 2) • Part 1 – The ACoP • Part 2 – Guidance on Control • Includes Guidance in Part 1 • Aim • to make clear the Employers duty under the COSHH Regs to control legionella

  10. Changes in the New ACoP (3) • Use of Risk Systems HAS TO BE AVOIDED in so far as is reasonably practicable • Previously SHOULD BE • Must assess practicality of removal of risk system • Now requires that you CONTROL the Risk • Previously MINIMISE the Risk

  11. Changes in the New ACoP (4) • Now has a requirement to have access to competent help when conducting a risk assessment • Code of Conduct for organisations providing water treatment services • Water Management Society • British Association of Chemical Specialities

  12. Changes in the New ACoP (5) • Greatly expanded section on Managing the Risk - gives advice on competence & training for those: • Developing, managing & conducting the risk assessment • Implementing controls • Managing external Contractors • Including detailed lines of communication

  13. Changes in the New ACoP (6) • Emphasises the duty of suppliers of products and services to: • Carry out work effectively • Liase with Duty Holders about deficiencies • Clearly define limitations of work undertaken • Ensure staff have necessary ability, training, information, resources etc. • Code of Conduct

  14. Design Requirements • Design requirements of L8 • Ensure that risk is reasonably avoided or, where not reasonably practicable; • Ensure that the plant or water system is so designed as to be safe and without risk when used • Provide on handover information as to safe usage. Such information should be updated as applicable.

  15. Changes in the Part 2 Guidance (1) Cooling Towers • Much greater detail on regimes of control • Routine quarterly testing of cooling towers for the presence of Lp (records kept for 5 yrs) • Table 1 – details weekly, monthly & quarterly tests for make-up water and cooling water • Action levels for Lp & aerobic bacterial counts outlined in Table 2

  16. Part 2 Guidance Cooling Towers • Must have regular programme of visual inspection • Particular attention is paid to: • Tower Pack

  17. Part 2 Guidance Cooling Towers • Must have regular programme of visual inspection • Particular attention is paid to: • Tower Pack • Drift Reducers

  18. Part 2 Guidance Cooling Towers • Must have a programme of water treatment effective against: • Corrosion • Scale formation • Fouling • Microbiological Activity

  19. Part 2 Guidance (2) Cooling Towers • Weekly • Conductivity • Oxidising Biocide Reserve • pH • Microbiological Activity (Dip Slide)

  20. Changes in the Part 2 Guidance

  21. Part 2 Guidance (2) Cooling Towers • Monthly • Hardness - Ca, Mg & Total !! • Oxidising Biocide Reserve • pH • Microbiological Activity (Dip Slide) • Chloride • Inhibitor Treatment Level • Concentration Factor

  22. Part 2 Guidance (2) Cooling Towers • Quarterly • Legionella • Total Alkalinity & Sulphate • Suspended Solids • Soluble & Total Iron • Temperature

  23. Part 2 Guidance (2) Cooling Towers • Cleaning & Disinfection • Before tower first commissioned • After shutdown of more than one month • If any mechanical work undertaken • If cleanliness is in doubt • If microbial test results show a problem • Temperature • Every six months

  24. Microbial Monitoring – Action Levels

  25. Changes in the Part 2 Guidance (2) Domestic Hot & Cold Water Systems • Removal of the limit of 300 litres for DHW • TMVs given recognition and procedures outlined • Table 3 & Checklist 2 introduced as guides to monitoring • Sentinel outlets introduced • Temperature measurement on DHW return • Annual tap temps reduced to “representative”

  26. Changes in the Part 2 Guidance

  27. Changes in the Part 2 Guidance (3) Showers • Now included!! • Procedures outlined for showers served by TMVs (include hot supply as sentinel outlet) • Checklist 2 gives guide to monitoring • Shower heads – quarterly or as necessary • Flush little-used outlets weekly

  28. Changes in the Part 2 Guidance (4) Other Risk Systems • Checklist 3 includes: • Water misting systems • Air washers & wet scrubbers • Dental equipment • Car/bus washes • Fountains & water features • Etc.

  29. Part 2 Guidance Hot & Cold Water Systems • Monthly • Calorifier Temperatures – Flow & Return • Sentinel Taps (Nominal Nearest & Furthest) • Supplies to Thermostatic Mixing Valves

  30. Part 2 Guidance Hot & Cold Water Systems • Annual • All Monthly Tests • Representative Number of Hot Water Outlets

  31. Part 2 Guidance – Control Limits Hot & Cold Water Systems • Calorifier Temperatures • Flow >60°C & Return <50°C • Taps • Hot >50°C within 1 minute • Cold <20°C after 2 mins • Supplies to Thermostatic Mixing Valves • Same as Taps

  32. Legionella Monitoring – Action Levels

  33. Legionella Risk Assessment • Risk at Source • Condition • Accessibility • Cultivation Conditions • Temp & pH • Microbe Count & Water Change Rate • Exposure • Period and Type • Exposed Population

  34. Precautions & Control Scheme • Prepare a Suitable System of Control • Manual • Details • Written Scheme • Regime of Maintenance & Control • Responsible Persons • Reporting Procedures • Risk Assessments

  35. Lp High Risk Systems • Cooling Towers • Diligent Water Treatment Programme • Quarterly Lp Testing • Once or Twice Weekly Water Treatment Tests • Showers • Minimum Quarterly Clean/Descale of Shower Head • Weekly Flush Through of Low Usage Systems • Annual Lp Testing

  36. Implement & Manage the Precautions • Log Book • Water Treatment Results • Lp Tests • Temperature Measurements • Cleanliness of systems • Disinfection certificates etc

  37. Record Keeping • Keep Records • Manual (incl. Risk Assessments) • 2 Years • Log Book Records • 5 Years

  38. Responsible Person • Manage the Control Scheme • Training • Regular Reviews • Communication

  39. The Barrow Outbreak (1) • Britain’s Biggest Ever Outbreak of LD • 131 confirmed cases • Trawl of GPs nationwide shows 10 more suspected cases • 41 people still in hospital – 8 in intensive care • Majority of victims aged 55-75 - none <15yrs old • 4 Fatalities - 3 Women, 1 Man – all >50 yrs old • Mortality Rate 3.1%. Lower than norm - due to rapid diagnosis & more effective antibiotics

  40. The Barrow Outbreak (2) • Identifying the Source • Epidemiological link to centre of Barrow-in-Furness • HSE checked 132 locations in immediate area • Most rapidly eliminated – just 4 cooling towers • 3 proved negative for legionella spp • Causative organism identified as Legionella pneumophila serogroup 1 – subtype Benidorm • Strain isolated from some patients and the Forum 28 Arts Centre cooling tower

  41. The Barrow Outbreak The Forum 28 Arts Centre

  42. The Barrow Outbreak

  43. The Barrow Outbreak (3) • The Arts Centre Cooling System • 30 yrs old and in poor condition • Local Council responsible for site maintenance • Biocide dosing system malfunctioning? • Discharging “discoloured steam” into alleyway • Part of system not used, but not decommissioned • 6-monthly disinfection being done for free! • System believed to have been operating badly for some time

  44. The Barrow Outbreak

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