GUIDE 51 Third edition 2014-04-01 Safety aspects Guidelines for their inclusion in standards Aspects liés a la sécurité - Principes directeurs pour les inclure dans lesnormes Reference number ISO/IEC GUIDE 51:2014(E) ISo LEC @IS0/IEC2014 ISO/IEC GUIDE 51:2014(E) COPYRIGHTPROTECTED DOCUMENT @IS0/IEC2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form written permission. Permission can be requested from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 : CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii @ IS0/IEC 2014 - All rights reserved IS0/IEC GUIDE 51:2014(E) Contents Page Foreword ..iv Introduction. ..V 1 Scope. ..1 2 Normative references 3 Terms and definitions 4 Use of the terms"safety" and "safe" 5 Elements of risk ..3 6 Achieving tolerable risk ..4 6.1 Iterative process of risk assessment and risk reduction ..4 6.2 Tolerable risk .5 6.3 Risk reduction. .6 6.4 Validation.. ..8 7 Safety aspects in standards .8 7.1 Types of safety standard ..8 7.2 Analysis of proposed new standards 7.3 Preparatory work. .9 7.4 Drafting. 10 Bibliography .14 @ IS0/IEC 2014 - All rights reserved iii