BS EN ISO 16954-2015 pdf download.Dentistry一Test methods for dental unit waterline biofilm treatment.
Depending upon the speellic technical approach of a trrtnient method and Its intended bonefit, the performance objertiws of a dental unit procedural water delivery system treatment method c-an inc-lode flue or both of the following:
— prevention or Inhibition or blot urn formation on surfaces within the deuit-al unit procedural water deli. cry system;
— removal of blot jim from surfaces within the dental unit procedural water delivery systenL
This International St.indard specifies separate test methods for each of the above performance obqectives. These requirements can be expanded upon, for example to include add ltkmal replicates or test scenarios Additions to the test method shall follow the general principles of this International Standard and be fully described In the test report
S Test water and bacterial challenge suspensions
5.1 Test water
This subcbuse specifies the preparation of test water prior to inocubtlon,
5.1.1 Reagents
5,1.1.1 Water, in accordance with ISO 3696:1987, grade 3.
5.1.1.2 Calcium chloride (CaCI2). or an equivalent molar quanuty of a calcium chloflde hydrate.
5.1.1.3 MagnesIum chloride (MgCl), or an equivalent molar quantityofa magnesium chloride hydrate.
5,1.1.4 Sodium bicarbonate (NalICO u)
5.1.1.5 Tryptic soy broth (TSR), l/3.strength. 10.0 g tryptic soy medium per litre broth.
5.1.1.6 Sodium hydroxide (NaOH), 1 mol/I.
5.1.1.7 HydrochlorIc add (Ha), I mol/l.
5.1.2 Preparation of hardness stock solution I
Dissolve 74,0 g of calcium chloride (5.1.1.2) and 31.7 go magnesium c-blonde (5.113) in 1.00 I water (5.1.1.1).Hardness stocksolution I shall be stefllized by heat orlilter—sterilized usinga 0.2 pm microfiker and used within 24 h or stored at (St 3) C for up o 6 months.
5.1.3 PreparatIon of hardness stock solution 2
Dissolve 56,0 g of sodium bicarbonate (511.4) in 1.001 water (5.1.1.1). Hardness stock solution 2 shall be filter-sterilized usIng 0,2 m microfiher and used within 24 h or stored at (5 t 3) C for up we months. Ilardncss stock solution 2 Is not to be heat sterilized.
5.1.4 Preparation of test water prior to Inoculation
For eat-h litre of test water to be prepared, add 1.00 ml of 1(3-strength TSB (ILLS) and 1,80 ml of hardness stock solution 1(11.2) to 1.00 I water (11.11) and steam sterilize, Alter the sterilized solution has cooled, for each litre of test water add 4,00 ml of hardness stock solution 2 whwh has been filter sterilized using a 0,2 pm mlcrofiiter. Adlust the pH to 7,0 to 80, measured according to ISO 10523, by adding sodium hydroxide (11.1.6) or hydrochloric acid (11.11). The test water shall be used within 24 hot stored at (52 3) C for up to one week.
NOTE I The hardnessoftheprepared test waterts approximately 1.8 mmcl of calcium lonsperlitre (equivalent to approximately 180 mg/I as CaCO4 This corresponds to the upper limC of the generally accepted range br hard water l1iJ
NOTE 2 The test water has a Concentration of approxImately 10 n TSR per litre, which yields a total organic carbon (TOC) level ol approslni.ately 4 mg/I, although the exact TOC level might vary uionwwhat.BS EN ISO 16954 pdf download.