H-09-0 29-hb2h 4851903 0036268 F.7/-01 International Standard (ISo 4794 Laboratory glassware - Methods for assessing the chemical resistance of enamels used for colour coding and colour marking Verreriede laboratoire -Methodes d'évaluation de la résistance chimique des émaux utiliseés pour le code de couleurs et les couleurs d'identification First edition -- 1982-05-01 S0 4794-1982 (E) UDC 542.3 : 666.29 : 620.193.4 Ref.No.ISO4794-1982(E) Descriptors : glassware, laboratory glassware, pipettes, tests, enamels, chemical resistance, colour codes. mational Oroanization for Standardization Price based on 2 pages 29-h62h EObTSh 6929E00 Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (iso member bodies). The work of developing Inter- national Standardsis carried out throughIsO technical committees.Everymember body interested in a subject for which a technical committee has been set up has the Draft International Standards adopted bythe technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the Iso Council. International Standard ISO 4794 was developed by Technical Committee ISO/TC 48, Laboratory glassware and related apparatus, and was circulated to the member bodies inJune1979. Australia india Romania Czechoslovakia Israel South Africa, Rep. of Egypt, Arab Rep. of Italy Spain France Korea, Rep. of United Kingdom Germany, F. R. Mexico USA Hungary Poland USSR No member body expressed disapproval of the document. International Organization forStandardization,1982 Printed in Switzerland Coovriaht Intemational Oroanization for Standardization 29-hb2h 4851903 0036270 INTERNATIONALSTANDARD ISO4794-1982(E) Laboratory glassware - Methods for assessing the chemical resistance of enamels used for colour coding and colour marking 0 Introduction Iso 3819, Laboratory glassware -Beakers.1) The following methods of testare intended to give an assess- ment of the chemical resistance of colour marking enamels 3 Reagents used on laboratory glassware, e.g. pipettes colour coded ac- cording to ISO 1769. Detergent and acid solutions have been chosen to represent the most severe conditions to be en- 3.1 Distilled water or deionized water. countered in practice. 3.2 Detergent solution. Aproposal to include a testfor resistance to autoclaving was considered, but was rejected as unnecessary on the grounds Dissolve 50 g of tetrasodium pyrophosphate (NayP207) and 5 g that the test for resistance to detergent solutions would cover of sodium dodecylbenzene sulphonate (C1sH2gSO3Na) in 1 litre the same ground. of water. Consideration was also given to a test involving immersion in a 3.3 Hydrochloric acid [c(HCl)=2 mol/l],analytical grade. chromic/sulphuric acid solution, but this was thought to be un- necessarybecauseofthedecreasinguseofthesesolutionsfor 3.4 Acetone (CHsCoCH3),pure. cleaning laboratoryglassware,thedifficultyinspecifyingsuch a solutionprecisely,and evidencethat thedegreeof attack on colour coding enamels would be no greater than with the hydrochloric acid solution specified in this International 4. Apparatus Standard. 4.1. .Beaker, of capacity 1 litre, compiying with Iso 3819. Scope and field of application 4.2 Beaker cover glass, of diameter sufficient to cover the This International Standard specifies test methods for the 1 litre beaker (4.1). assessmentoftheserviceperformanceofenamelsusedforcol- our coding and colour marking of laboratory glassware. It does 4.3 Heating bath, with suitable heating equipment which not purport to classify enamels by their degree of resistance; it enables a test solution to be maintained at a constant provides standard procedures for determining whether an temperature of 80 ± 1 oc. enamel resists the specified treatment without a change such that the colour can no longer be identified, or might be con- fused with any other colour used in colour coding. 4.4 Sample holder,