PARKER BATH

Additional Manufacturer Narrative

(B)(4). THE PARKER BATH IS A BATH SYSTEM INTENDED FOR ASSISTED BATHING. IT WAS REPORTED TO US THAT LEGIONELLA WAS FOUND IN TWO PARKER BATHS. THE BRAND NEW FACILITY HAS INSTALLED TWO LEGACY PARKER BATHS AND SINCE THEN HAD REOCCURRING PROBLEMS WITH TOO HIGH LEGIONELLA COUNTS (AS HIGH AS 10,000 CFU/LTR) SPECIFICALLY RELATED TO THESE 2 BATHS. THE BATHS ARE SUPPLIED WITH INCOMING WATER WITH TEMPERATURES 20 DEGREES C (COLD WATER) AND 50 DEGREES C (HOT WATER). THE FACILITY HAS MADE SEVERAL ATTEMPTS TO CHEMICALLY SANITISE THE SYSTEM BUT FAILED. MAINTENANCE OF THE BATHS IS REPORTED TO BE PERFORMED BY THE CUSTOMER ACCORDING TO THE L8 APPROVED CODE OF PRACTICE AND GUIDANCE. THE BATHS ARE USED DAILY ON WEEKDAYS AND FLUSHED DAILY ON WEEKENDS. THE MANUFACTURER'S INVESTIGATION IS NOW COMPLETED AND CONCLUDES; A REVIEW OF PREVIOUS COMPLAINTS SHOWED NO EARLIER REPORTS OF A LOW TREND OF COMPLAINTS INDICATING LEGIONELLA HAS BEEN FOUND ON OTHER BATH SYSTEMS MANUFACTURED BY ARJOHUNTLEIGH. HOWEVER, COMPARED TO THE NUMBER OF BATHS ACTIVE IN THE MARKET THE TREND IS EVALUATED AS LOW. THE ROOT CAUSE OF THE REOCCURRING LEGIONELLA INFECTION APPEARS TO BE AN UNDEFINED TIME PERIOD OF THE BATH BEING DISCONNECTED AND OUT OF USE AND A TOO LOW HOT WATER TEMPERATURE OF INCOMING WATER. THE LEGIONELLA BACTERIA ARE COMMON IN WATERCOURSES IN LOW CONCENTRATIONS. IT GROWS WITH TIME IN WATER TEMPERATURES MOSTLY BETWEEN 20 DEGREES C AND 45 DEGREES C. LEGIONELLA BACTERIA ALSO REQUIRE A SUPPLY OF NUTRIENTS TO MULTIPLY SUCH AS ALGAE, AMOEBAE AND OTHER BACTERIA. SEDIMENT, SLUDGE, SCALE AND BIOFILMS IS AN IMPORTANT FACTOR IN PROVIDING CONDITIONS IN WHICH THE LEGIONELLA MAY GROW. A BIOFILM IS A THIN LAYER OF MICRO ORGANISMS WHICH MAY FORM A SLIME ON THE SURFACES IN CONTACT WITH WATER. SUCH BIOFILMS, SLUDGE, OR SCALE CAN PROTECT LEGIONELLA BACTERIA FROM TEMPERATURES AND CHEMICAL TREATMENTS THAT WOULD NORMALLY KILL OR INHIBIT THE ORGANISMS. A BATH THAT IS DISCONNECTED AND TAKEN OUT OF USE FOR A TIME PERIOD LEAVING A VENTED, SEMI HUMID ENVIRONMENT INSIDE THE PIPES IS A FAVORABLE SURROUNDING FOR THE BACTERIA TO GROW, CREATING A HEAVY BIOFILM. WE CONSIDER IT IS HIGHLY THAT THE LEGIONELLA CONTAMINATION ORIGINATES FROM THE BATH SYSTEM BUT RATHER FROM THE FACILITY PIPES. FROM THE INFORMATION COMMUNICATED BY THE CUSTOMER IT APPEARS THAT THE BATH HAS BEEN TAKEN OUT OF USE FOR A TIME PERIOD AND THEN BEEN REINSTALLED IN THE NEW SCHOOL BUILDING. IT IS REASONABLE TO SUGGEST THAT THE BIOFILM THAT WAS CREATED DURING THIS TIME IS TOO HEAVY TO SANITISE WITH CHEMICAL OR THERMAL TREATMENT. WHEN ELIMINATING LEGIONELLA BACTERIA TIME IS IMPORTANT. IF THE TEMPERATURE OF HOT WATER INSTALLATION IS 50 DEGREES C, IT TAKES BETWEEN FIVE AND 10 HOURS TO KILL 90% OF THE BACTERIA. AT A WATER TEMPERATURE OF 60 DEGREES C, THE CORRESPONDING TIME IS LESS THAN 10 MINUTES AND AT TEMPERATURES OF 70 DEGREES C, 90% DIE IN LESS THAN 10 SECONDS. ANOTHER LIKELY CAUSE FOR THE LEGIONELLA GROWTH IS THE TOO LOW HOT WATER TEMPERATURE OF 50 DEGREES C. THE RECOMMENDED HOT WATER TEMPERATURE FOR THE PARKER 420 MODEL AT THE TIME THIS BATH WAS MANUFACTURED WAS BETWEEN 52 AND 65 DEGREES C. RECOMMENDATIONS HAS SINCE THEN TIGHTENED AND FOR THE NEW PARKER 500 MODEL THE RECOMMENDED HOT WATER TEMPERATURE IS BETWEEN 60 AND 80 DEGREES C. THE PARKER BATH IS DESIGNED IN A WAY THAT PREVENTS STAGNANT WATER BEING LEFT IN THE PIPES GIVING BACTERIA SUCH AS LEGIONELLA A POSSIBILITY TO GROW. OUR BATHS SYSTEMS ARE ALSO DESIGNED ACCORDING TO BS 6920 TO INHIBIT GROWTH OF MICRO ORGANISMS. THE DESIGN IS VERIFIED AND CERTIFIED BY (B)(4).

Description of Event or Problem

(B)(4).