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Lexa PLUS | Instructions for Use | RIS-311 ENG Rev03 | 29/08/2022 | © W&H Sterilization Srl
Technical data
Water quality
FEED WATER SPECIFICATIONS (ANSI/AAMI AND AAMI TIR34)
The table below lists the specifications for the water used for steam
sterilization according ANSI/AAMI ST55 and AAMI TIR34. Following is
the Table 1 AAMI TIR34.
Units
Utility water
1
flushing/ washing/
rinsing
Critical water
finale rinse
2
/steam
Hardness
mg/L
< 150
3
< 1
Conductivity
µS/cm
< 500
< 10
Total Dissolved
Solids
ppm
< 350
< 6.5
pH
4
6 – 9
5 – 7
Chlorides
mg/L
< 250
< 1
Bacteria
cfu/mL
n/a, <10
5
< 10
Endotoxin
EU/mL
n/a, <20
5
< 10
Note 1
: This is the quality of water that might come from the tap but might
need some form of treatment to achieve these specifications.
Note 2
: If this is the final rinse prior to sterilization of a critical device.
Note 3
: If hardness is greater than 150 mg/L, a water softener is
recommended unless used for washing and the cleaning chemistry is
capable of handling higher levels of hardness.
Note 4
: For boiler-treated steam, most boilers are treated to maintain a pH of
7.5 or 8.5. Any treatment of water that goes into boilers should be in
accordance with the sterilizer and boiler manufacturers' written IFU.
Note 5
: After high-level disinfection.