ISO INTERNATIONAL STANDARD 10229 First edition 1994-12-01 Water quality - Determination of the prolonged toxicity of substances to freshwater fish -- Method for evaluating the effects of substances on the growth rate of rainbow trout [Oncorhynchus mykiss Walbaum (Teleostei, Salmonidae)) Qualité de I'eau -- Détermination de la toxicité prolongée de substances vis-a-vis d'un poisson d'eau douce - Méthode d'évaluation des effets de substances sur le taux de croissance de la truite arc-en-ciel[Oncorhynchus mykiss Walbaum (Teleostei, Salmonidae) OSI Reference number ISO10229:1994(E) IS010229:1994(E) Foreword ISO (the International Organization for Standardization) is a worldwide of preparing International Standards is normally carried out through IsO which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with IsO, also take part in the work. isO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. circulated to the member bodies for voting. Publication as an International a vote. ISO/TC 147,Water quality,SubcommitteeSC 5,Biological methods. Annexes A and B of this International Standard are for information only. ISO 1994 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form orby any means,electronic ormechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case Postale 56· CH-1211 Geneve 20· Switzerland Printed in Switzerland ii @ISO ISO10229:1994(E) Introduction This International Standard describes methods of determining the long- determination of lethal and sublethal responses. In all cases, the specified possible for the methods presented here to be used for other species of freshwater fish, provided that appropriate modifications to, for example, quality of water used for dilution,temperature conditions and feeding rates are made and the relationships between growth rates, feeding rates and conversionefficiencies are established Within this International Standard, a choice may be made between semi- static and flow-through methods. These have already been described for the determination of the acute lethal toxicity of substances to a freshwater fish in ISO 7346-2 and ISO 7346-3 respectively. The choice of the method of presentation of the test solution depends on two factors: the nature of the test substance and the form of the test method. The flow-through method can be used for most types of substances, in- cluding those unstable in water, but the concentrations of the test sub- stance are determined wherever possible. The semi-static method can be used for testing those substances whose concentrations can be main- tained satisfactorily throughout the test by renewal of the solutions every 24 h. To assist in the preparation and maintenance of concentrations of sub- stances which may invoke the chosen responses in the fish at concen- trations close to that of their aqueous solubility, a small volume of solvent issometimesused,asspecifiedinthemethods. ii