1、BRITISH STANDARD BS 2893:1989 Specification for Chemical preparations for portable and transportable chemical closets (excluding those for use in aircrafts) UDC 615.28:628.42BS2893:1989 This British Standard, having been prepared under the directionof the Disinfectants Standards Committee, was publi
2、shed under the authority ofthe Board of BSI and comes intoeffect on 31July1989 BSI 09-1999 First published September 1957 First revision July 1989 The following BSI references relate to the work on this standard: Committee reference DIC/1 Draft for comment 87/52832 DC ISBN 0 580 168026 Committees re
3、sponsible for this British Standard The preparation of this British Standard was entrusted by the Disinfectants Standards Committee (DIC/-) to Technical Committee DIC/1, upon which the following bodies were represented: Association of District Councils British Association for Chemical Specialities C
4、aravan Club Chemical Industries Association Consumer Policy Committee of BSI Department of Trade and Industry (Laboratory of the Government Chemist) Institution of Environmental Health Officers Society of Chemical Industry Water Authorities Association Amendments issued since publication Amd. No. Da
5、te of issue CommentsBS2893:1989 BSI 09-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Antimicrobial value 1 4 Colour stability 1 5 Stability before dilution 1 6 Stability after dilution 1 7 Flash point 1 8 Compatibility with closet materials 1
6、9 Marking and labelling 1 Appendix A Recommendations for properties of the product that cannot be specified objectively 2 Appendix B Method of test for antimicrobial value 2 Appendix C Method of test for colour stability 5 Appendix D Method of test for stability after dilution 5 Appendix E Method fo
7、r determination of compatibility with closet materials 5 Table 1 Examples of growth pattern 5 Table 2 Test solutions 5 Publications referred to Inside back coverBS2893:1989 ii BSI 09-1999 Foreword This revision of this British Standard has been prepared under the direction of the Disinfectants Stand
8、ards Committee. It supersedes BS2893:1957, which is withdrawn. The chemical preparations usually contain biocidal ingredients, colouring and wetting agents and may contain re-odourizing agents for masking odours and are intended to be used in one or more of the following types of closet: a) non-flus
9、hing closets; b) flushing closets of the non-recirculating type; c) flushing closets of the recirculating type; including those complying with BS2081, except for closets used on board aircraft. The main changes introduced in this revision are: 1) the biological efficacy of the preparations is specif
10、ied in terms of performance rather than compositional requirements; 2) the attributes that cannot be specified objectively have been transferred toAppendix A. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for the
11、ir correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages1 to 6, an inside back cover and a back cover. This standard has been updated (see
12、 copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS2893:1989 BSI 09-1999 1 1 Scope This British Standard specifies performance requirements for chemical preparations for use in portable and transportable chemical close
13、ts, except for closets used in aircraft. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this standard, the definitions listed in BS5283 apply, together with the following. 2.1 product the chemical preparation as
14、marketed by the manufacturer or supplier NOTEChemical preparations are hereafter referred to as “the product” 2.2 prime dilution the highest recommended concentration when first charging the chemical closet with product and water NOTEThis is often referred to as prime charge. 2.3 maximum dilution th
15、e minimum concentration of the product recommended by the supplier NOTEThe maximum dilution is normally expressed in relation to maximum working capacity of a closet 3 Antimicrobial value The product at60% of its maximum dilution shall have an antimicrobial value at least equivalent to a0.6 g/L solu
16、tion of formaldehyde, i.e. shall pass the test described inAppendix B. 4 Colour stability The colour of the preparation at maximum dilution shall not discolour or break down after being kept for72 1h at pH3 0.5 and at pH11 0.5, when tested in accordance with the method described inAppendix C. 5 Stab
17、ility before dilution Two separate samples of the preparation, after standing for three months at5 2 C and30 2 C respectively, shall still meet all the requirements of this standard. The samples under examination shall be stored in the original, sealed and unopened retail containers. The samples sha
18、ll be stored so that they are not exposed to direct sunlight or to localized overheating. 6 Stability after dilution Solutions of the product at prime dilution and at maximum dilution in both deionized water and standard hard water shall not break up or separate when left standing for72 1h at5 2 C a
19、nd at30 2 C when tested in accordance with the method described inAppendix D. 7 Flash point A prime dilution of the product shall have a flashpoint not lower than65 C, when tested by the method described in BS2000-34. NOTEThe test procedure need not be completed if the flashpoint has not been reache
20、d at65 C. 8 Compatibility with closet materials The product shall not cause any perceivable deterioration of the materials of construction of those types of closet complying with BS2081 for which the supplier recommends the product when tested in accordance with the method described inAppendix E. 9
21、Marking and labelling The retail container of the product shall be marked with, or shall have attached to it a label bearing the following: a) full details of the type(s) of closet for which use of the product is recommended; b) instructions for safe handling of the product (including an instruction
22、 not to mix with other chemicals) and for safe and environmentally acceptable procedures for discharging the mixture of diluted product and soil from the closet; c) instructions for preparing the prime dilution and information on the maximum dilution recommended by the supplier and its relationship
23、to maximum working capacity of the closet; d) instructions for safe storage of the product; e) the number and date of this British Standard, i.e. BS2893:1988 1) . 1) Marking BS2893:1988 on or in relation to a product represents a manufacturers or suppliers declaration of conformity, i.e. a claim by
24、or on behalf of the manufacturer that the product meets the requirements of the standard. The accuracy of the claim is therefore solely the responsibility of the person making the claim. Such a declaration is not to be confused with third party certification of conformity, which may also be desirabl
25、e.BS2893:1989 2 BSI 09-1999 Appendix A Recommendations for properties of the product that cannot be specified objectively A.1 Introduction This appendix describes properties that should be present in the product but that are not specified objectively. Inclusion of corresponding requirements in claus
26、e3 would therefore not result in a specification with which compliance could with confidence be claimed, challenged or determined. Suppliers should normally ensure that their products possess these properties to the necessary degree and should formulate the products accordingly on the basis of exper
27、ience and users views. A.2 Colour A.2.1 The product should contain sufficient colour, preferably blue or green shades, to mask organic waste and indicate a chemically charged toilet. A.2.2 In the case of products recommended for use in non-flushing closets without a covered waste container, the prod
28、uct even at maximum dilution should contain sufficient colouring matter to obscure from sight submerged excreta and paper. A.2.3 In the case of products recommended for use in flushing closets of the recirculating type, the diluted product should contain sufficient colouring matter, or alternatively
29、 decolourizing material, to ensure that the flush is always of an acceptable appearance. A.3 Odour The diluted product should be free from objectionable odour. A.4 Deodorant or reodorant action The diluted product should remove or mask malodours rapidly and effectively from human excreta and leave a
30、n acceptable level of odour in the closet. A.5 Gas prevention The diluted product should prevent the release of obnoxious or explosive gases from human excreta. A.6 Effects on skin and mucous membranes In the case of products recommended for use in non-flushing toilets without covered waste containe
31、rs, the diluted product should be non-injurious to the skin and mucous membranes. A.7 Cleansing The composition of the diluted product should facilitate rinsing out of the waste container after emptying. A.8 Period of effectiveness In use, the diluted product, if not further dilute and if all the so
32、lid material is fully submerged, should retain effectively the properties described inA.2 toA.7 inclusive for at least3 days at temperatures of5 2 C and30 20 C. Appendix B Method of test for antimicrobial value B.1 Principle A challenge culture is mixed with a fixed amount of yeast suspension. This
33、mixture constitutes a challenge medium which is then added in a specified amount to a specific dilution of the product under test; further additions are made after24h and48h. After contact times of24h, 48h and72h, aliquot portions are taken and placed in tubes containing inactivator. After5min, aliq
34、uot portions are taken from these tubes and placed in five replicate tubes of recovery broth and are incubated at37 C for48h and then examined for growth. The procedure is repeated using a fixed amount of formaldehyde solution in place of the solution under test, as a check. NOTE 1The overall result
35、 is determined using information obtained for product contact times of24h and48h only. This method makes reference to a product contact time of72h and the procedure relating to this contact time may be omitted. However, operators often find it useful to apply the method, as described, especially as
36、contact times of24h, 48h and72h apply for the formaldehyde test dilution. NOTE 2This method is based on that described in BS6905 but differs with regard to contact times and comparison of product performance with that of a solution of0.6 g/L formaldehyde. Operators may find it useful to read BS6905.
37、 B.2 Sterilization Reagents, media, materials and apparatus shall be sterilized by being kept at either: a) 170 C to 175 C for not less than1h in an oven (dry sterilization 2) ); or b) 121 1 C for not less than15min in an autoclave (wet sterilization). Manipulation of sterile material and of bacteri
38、al cultures shall be carried out aseptically. B.3 Reagents and materials B.3.1 General. All reagents shall be of recognized biological or analytical grade and distilled water or water otherwise produced shall comply with BS3978. All solutions and media shall be freshly prepared. 2) This method is su
39、itable for dry glassware only.BS2893:1989 BSI 09-1999 3 B.3.2 Hard water. Dissolve0.305g of anhydrous calcium chloride and0.139g of magnesium chloride hexahydrate in water and dilute to1000mL with water. Sterilize in accordance withB.2. NOTEThe water has a value of 342 mg/L hardness. B.3.3 Recovery
40、medium. Using a pipette or an automatic dispenser (4.2.2), dispense standard strength Oxoid Nutrient No. 2 broth 3) , containing30g/L of Tween80 3) , into test tubes in10mL aliquot portions and sterilize in accordance withB.2. Each test requires30 such tubes. B.3.4 Solid culture medium. Prepare Oxoi
41、d Nutrient Agar 3)in accordance with the manufacturers instructions and sterilize in accordance withB.2. B.3.5 Test organism. Escherichia coli NCTC 8196. NOTEThis organism has been categorized by the Advisory Committee on Dangerous Pathogens as a hazard group2 pathogen and work with viable material
42、should be conducted according to their recommendations for containment level2. B.3.6 Yeast suspension. Prepare a yeast suspension containing50g/L calculated on a dry mass basis as described in5.5 of BS808:1986, but using the hard water (B.3.2) in place of water complying with BS3978. B.3.7 Inactivat
43、or solution. Dissolve 20g of egg lecithin and30mL of a10% (m/m) approximately, aqueous solution of Lubrol W 3)and dilute to1000mL with water. Dispense into test tubes in9mL aliquot portions and sterilize in accordance withB.2. Each test requires six such tubes. B.3.8 Ringers solution, quarter streng
44、th. Use freshly prepared solution. Dissolve9.00g of sodium chloride, 0.42g of potassium chloride, 0.24g of anhydrous calcium chloride and0.20g of sodium hydrogen carbonate in water and dilute to 1000mL with water. Add one volume of this solution to three volumes of water to give a quarter-strength s
45、olution. Dispense9mL aliquot portions into sterile universal container culture bottles (B.4.2.3) and sterilize in accordance withB.2. NOTETablets are commercially available. B.3.9 Liquid growth medium. Standard strength Oxoid Nutrient No. 2. B.3.10 Formaldehyde solution of known concentration. NOTEA
46、nalytical grade formaldehyde solution contains37% to41% (V/V) formaldehyde and10% to14% (V/V) methanol as a stabilizer. It is necessary to know the exact concentration to prepare the test dilution (seeB.7.2). The concentration may be measured using the method described in BS2942. B.4 Apparatus B.4.1
47、 General. The apparatus shall be sterile (seeB.2) and scrupulously clean before use. B.4.2 Ordinary microbiological apparatus B.4.2.1 Micropipetter, high precision, adjusted to dispense accurately2004L, with sterile tips suitable for use with the micropipetter. B.4.2.2 Graduated pipettes, capable of
48、 delivering2mL, 6mL and9mL, and complying with classB of BS700-1, or an automatic dispenser capable of delivering2mL, 6 mLand9mL with the same degree of accuracy. B.4.2.3 Universal container culture bottles, of capacity28mL. NOTEThe containers should be made of glass with screwed metal caps with rub
49、ber liners. B.2.4.4 Incubator, capable of being controlled at37 1 C. B.5 Preparation of test cultures B.5.1 Initial cultures Obtain the test organism (B.3.5) in a tube in freeze-dried form and reconstitute in accordance with the suppliers instructions. B.5.2 Stock cultures Spread a loopful of the initial culture (B.5.1) over the surface of a slope of sterilized solid culture medium (B.3.4). Incubate for24h in the incubator(B.2.4.4) controlled at37 10 C, and then store at below22 C and preferably between4 C and10 C, until required. B.5.
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