EN ISO 14798:2013

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aufzüge, Fahrtreppen und Fahrsteige - Verfahren zur Risikobeurteilung und Verringerung (ISO 14798:2009)Ascenseurs, escaliers mécaniques et trottoirs roulants - Méthodologie de l'appréciation et de la réduction du risque (ISO 14798:2009)Lifts (elevators), escalators and moving walks - Risk assessment and reduction methodology (ISO 14798:2009)91.140.90Lifts. EscalatorsICS:Ta slovenski standard je istoveten z:EN ISO 14798:2013SIST EN ISO 14798:2013en,de01-junij-2013SIST EN ISO 14798:2013SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN ISO 14798
January 2013 ICS 91.140.90 English Version
Lifts (elevators), escalators and moving walks - Risk assessmentand reduction methodology (ISO 14798:2009)
Ascenseurs, escaliers mécaniques et trottoirs roulants - Méthodologie de l'appréciation et de la réduction du risque (ISO 14798:2009)
Aufzüge, Fahrtreppen und Fahrsteige - Verfahren zur Risikobeurteilung und -minderung (ISO 14798:2009) This European Standard was approved by CEN on 24 November 2012.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.
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B-1000 Brussels © 2013 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14798:2013: ESIST EN ISO 14798:2013

Reference numberISO 14798:2009(E)© ISO 2009
INTERNATIONAL STANDARD ISO14798First edition2009-03-01Lifts (elevators), escalators and moving walks — Risk assessment and reduction methodology Ascenseurs, escaliers mécaniques et trottoirs roulants — Méthodologie de l'appréciation et de la réduction du risque
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ii © ISO 2009 – All rights reserved
ISO 14798:2009(E) © ISO 2009 – All rights reserved iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Terms and definitions.1 3 General principles.3 3.1 Concept of safety.3 3.2 Concept of risk assessment.3 4 Risk analysis procedure.5 4.1 Step 1 — Determination of the reason for conducting a risk assessment.5 4.2 Step 2 — Formation of a risk assessment team.5 4.3 Step 3 — Determination of the subject of risk assessment and related factors.6 4.4 Step 4 — Identification of scenarios: hazardous situations, causes and effects.8 4.5 Step 5 — Risk estimation.9 5 Step 6 — Risk evaluation.15 6 Step 7 — Has the risk been sufficiently mitigated?.15 7 Step 8 — Reduction of risk — Protective measures.16 8 Documentation.17 Annex A (normative)
Risk assessment template.18 Annex B (informative)
Quick references to hazards (Table B.1), hazardous situations (Table B.2), causes (Table B.3), effects (Table B.4) and harm (Table B.5).20 Annex C (normative)
Estimation of risk elements —
Severity (Table C.1) and probability (Table C.2).25 Annex D (normative)
Risk estimation and evaluation.26 Annex E (informative)
Role of the team moderator.28 Annex F (informative)
Examples of a risk assessment and protective measures.32 Bibliography.38
ISO 14798:2009(E) iv © ISO 2009 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 14798 was prepared by Technical Committee ISO/TC 178, Lifts, escalators and moving walks. This first edition of ISO 14798 cancels and replaces ISO/TS 14798:2006, which has been technically revised.
ISO 14798:2009(E) © ISO 2009 – All rights reserved v Introduction The objective of this International Standard is to describe principles and set procedures for a consistent and systematic risk assessment methodology relevant to lifts (elevators), escalators, moving walks (“lifts”, for short). The risk analysis and assessment principles and process described in this International Standard may, however, be used for assessment of risk relevant to equipment other than lifts. This risk assessment methodology is a tool used to identify risk of harm resulting from various hazards, hazardous situations and harmful events. Knowledge and experience of the design, use, installation, maintenance, incidents, accidents and related harm are brought together in order to assess the risk during all phases of the life of lifts 1) (elevators), escalators and moving walks (hereafter referred to as “lifts”), from design and construction up to decommissioning. The users of the methodology do not make medical judgements but, rather, evaluate events that can possibly lead to levels of harm defined in this International Standard. By itself, this International Standard does not provide a presumption of conformity to any safety requirements for lifts, including those noted in Clause 1. NOTE Risk assessment is not an exact science, as there is a certain degree of subjectivity in the process. It is recommended that this International Standard be incorporated into training courses and manuals so as to provide basic instructions on safety aspects to those involved in a) assessing designs, operations, testing and use of lift equipment, and b) writing of specifications or standards incorporating safety requirements for lifts. This International Standard describes a qualitative methodology for risk assessment that relies very much on the judgement and deliberations of the members of the risk assessment team who carry out the assessment. To ensure the most realistic and consistent assessment, it is essential that the methodology be followed faithfully. Aids such as numeric methods of assessment that follow the format described in this International Standard are not precluded from use. It should, however, be recognized that numeric aids to qualitative methods may still retain some of the subjectivity inherent in the qualitative process. Clause 3 describes the concepts of safety and risk assessment. Clause 4 describes the procedure of risk analysis, including risk estimation. The procedure for risk evaluation is set out in Clause 5 and assessment in Clause 6. Clause 7 deals with protective measures. Clause 8 specifies relevant documentation.
1) Hereafter in this International Standard, the term “lift” is used instead of the term “elevator”. In addition, the term “lift” is also used instead of the terms “lifts, escalators and moving walks”. SIST EN ISO 14798:2013

INTERNATIONAL STANDARD ISO 14798:2009(E) © ISO 2009 – All rights reserved 1 Lifts (elevators), escalators and moving walks — Risk assessment and reduction methodology 1 Scope This International Standard establishes general principles and specific procedures for assessing risk. The purpose of this International Standard is to provide a process for making decisions relevant to the safety of lifts during the a) design, construction, installation and servicing of lifts, lift components and systems, b) development of generic procedures for the use, operation, testing, compliance verification and servicing of lifts, and c) development of technical specifications and standards affecting the safety of lifts. While examples in this International Standard refer primarily to risks of harm to persons, the risk assessment procedure set out in this International Standard can be equally effective for assessing other types of risk relevant to lifts, such as the risk of damage to property and environment. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 cause circumstance, condition, event or action that in a hazardous situation contributes to the production of an effect 2.2 effect result of a cause in the presence of a hazardous situation 2.3 harm physical injury or damage to the health of people, or damage to property or the environment [ISO/IEC Guide 51:1999, 3.3] 2.4 harmful event occurrence in which a hazardous situation results in harm [ISO/IEC Guide 51:1999, 3.4] NOTE In this International Standard, the term “harmful event” is interpreted as a combination of cause and effect. SIST EN ISO 14798:2013

ISO 14798:2009(E) 2 © ISO 2009 – All rights reserved 2.5 hazard potential source of harm NOTE The term “hazard” can be qualified in order to define its origin or the nature of the expected harm (e.g. electric shock hazard, crushing hazard, cutting hazard, toxic hazard, fire hazard, drowning hazard). [ISO/IEC Guide 51:1999, 3.5] 2.6 hazardous situation circumstance in which people, property or the environment are exposed to one or more hazards [ISO/IEC Guide 51:1999, 3.6] 2.7 life cycle period of usage of a component or a lift system 2.8 protective measure means used to reduce risk NOTE Protective measures include risk reduction by inherently safe design, protective devices, personal protective equipment, information for use and installation and training [ISO/IEC Guide 51:1999, 3.8] 2.9 residual risk risk remaining after protective measures have been taken [ISO/IEC Guide 51:1999, 3.9] 2.10 risk combination of the probability of occurrence of harm and the severity of that harm [ISO/IEC Guide 51:1999, 3.2] 2.11 risk analysis systematic use of available information to identify hazards and to estimate the risk [ISO/IEC Guide 51:1999, 3.10] 2.12 risk assessment overall process comprising a risk analysis and a risk evaluation [ISO/IEC Guide 51:1999, 3.12] 2.13 risk evaluation consideration of the risk analysis results to determine if the risk reduction is required 2.14 scenario sequence of a hazardous situation, cause and effect 2.15 severity level of potential harm SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 3 3 General principles 3.1 Concept of safety Safety, within this International Standard, is considered as freedom from unacceptable risk. There can be no absolute safety. Some risks, defined in this International Standard as residual risk, can remain. Therefore, a product or process (e.g. operation, use, inspection, testing, or servicing) can be only relatively safe. Safety is achieved by sufficient mitigation or reduction of the risk. Safety is achieved by the search for an optimal balance between the ideal of absolute safety, the demand to be met by a product or process, and factors such as benefit to the user, suitability for purpose, cost effectiveness and conventions of the society concerned. Consequently, there is a need to review continually the established safety levels, in particular when experience necessitates review of the pre-set safety levels and when developments, both in technology and knowledge, can lead to feasible improvements to attain sufficient mitigation of the risk compatible with the use of a product, process, or service. 3.2 Concept of risk assessment 3.2.1 Safety is achieved by the iterative process of risk assessment (risk analysis and risk evaluation) and risk reduction (see Figure 1). 3.2.2 Risk assessment is a series of logical steps that enables, in a systematic way, the examination of hazards associated with lifts. Risk assessment is followed, whenever necessary, by the risk reduction process, as described in Clause 7. When this process is repeated, it gives the iterative process for eliminating hazards as far as possible and for implementing protective measures. 3.2.3 Risk assessment includes: a) risk analysis 1) determination of the subject of analysis (see 4.3), 2) identification of scenarios: hazardous situations, causes and effects (see 4.4), and 3) risk estimation (see 4.5);
b) risk evaluation (see Clause 5). 3.2.4 Risk analysis provides the information required for the risk evaluation, which in turn allows judgements to be made on the level of safety of the lift and lift component, and any relevant process (e.g. operation, use, inspection, testing, or servicing). 3.2.5 Risk assessment relies on judgemental decisions. These decisions should be supported by qualitative methods complemented, as far as possible, by quantitative methods. Quantitative methods are particularly appropriate when the foreseeable severity and extent of harm are high. Qualitative methods are useful to assess alternative safety measures and to determine which one gives better protection. NOTE The application of quantitative methods is restricted by the amount of useful data that is available, and in many applications, only a qualitative risk assessment is possible. 3.2.6 The risk assessment shall be conducted so that it is possible to note down the procedure that has been followed and the results that have been achieved (see Clause 8). SIST EN ISO 14798:2013

ISO 14798:2009(E) 4 © ISO 2009 – All rights reserved
Figure 1 — Iterative process of risk assessment and risk reduction SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 5 4 Risk analysis procedure 4.1 Step 1 — Determination of the reason for conducting a risk assessment Before a risk assessment process can start, the reason for the assessment should be determined. It can be, but is not limited to, the following: a) verification that the risks are eliminated or sufficiently mitigated in relation to 1) design for, or installation of, a lift or a component, or a subsystem thereof, 2) the operation and use of a lift, or 3) procedures for testing, inspection, servicing, or performing any other work with intent to maintain the lift or a lift component in its intended operating conditions;
NOTE This especially applies to lifts and their components for which no recognized relevant safety standards are available. b) development of standards and regulations that stipulate requirements related to lift safety. 4.2 Step 2 — Formation of a risk assessment team 4.2.1 General Considering the variety in design, process and technology relevant to lifts, the diversity in the interests and working experience of lift experts, and in order to minimize any bias, a team approach for this risk assessment process is preferable. NOTE Risk assessment carried out by an individual might not be as comprehensive as that carried out by a team. 4.2.2 Team members Selection of the members of the risk assessment team, including the team moderator, is of paramount importance to the success of this risk assessment process. The team should be comprised of individuals with varied interests and having experience in all fields that can be affected by the product or process being assessed. EXAMPLE When assessing the design of a lift with a view to the safety of mechanics who will service the lift, the team can include persons with related work experience in construction, installation, testing, inspection and servicing, in addition to safety experts and experts in the design of various lift systems and subsystems. Experts with specialized knowledge may be engaged in a consulting role for all or appropriate portions of the risk assessment process. Such participation can significantly enhance the quality of the results. 4.2.3 Team moderator The team moderator should: a) have an overall understanding of the product or process being assessed; b) understand the risk assessment process; c) be able to assume an impartial view free of any bias; d) have “facilitating” abilities; e) act as a facilitator rather than participant in the debates of the team, and f) be able to facilitate arbitration when no team consensus can be reached. NOTE For further information on the role and responsibilities of the moderator, refer to Annex E. SIST EN ISO 14798:2013

ISO 14798:2009(E) 6 © ISO 2009 – All rights reserved 4.3 Step 3 — Determination of the subject of risk assessment and related factors 4.3.1 Determination of the subject of the assessment Once the reason for a risk assessment process is determined in accordance with 4.1, the subject of the assessment shall be determined as precisely as possible. Without limiting generalities, the subject may include one or more of the following: a) complete lift system 1) for a specific load, speed, travel, or range thereof, 2) for any location type, e.g. indoor or exposed to weather, in a public building or private residence, or in a factory or school, 3) for a specified or unspecified life cycle (see 4.3.2.2), 4) powered by any drive type (e.g. electric or hydraulic), 5) in a building that is accessible to the general public or that has strictly controlled use and access thereto, and 6) for the transportation of persons from the general public, a defined category of persons, goods only, or a combination thereof; b) component or subsystem of a lift in a), such as 1) enclosure of lift car, lift well, machine room or machinery space, 2) drive system or braking system, during normal operation or in case of emergency; 3) entrances to lift car and lift well (hoistway), machine room or well pit area, 4) operation control or motion control, incorporating diversified or specific technologies, and 5) locking devices; c) persons in relation to a lift in a), such as those who 1) use the lift for transportation, 2) are in, or could gain access to, the area where any part of the lift is located or operated, 3) perform any work on, or in the vicinity of, a lift, such as installing, testing, inspection, servicing, repairing, altering, rescuing, or cleaning (e.g. cleaning pit, car or well enclosures), 4) have certain physical disabilities, and 5) perform specific functions, e.g. fire fighting or transportation of hospital patients; d) processes related to a lift or its components, such as 1) installation, 2) service, 3) repair, 4) cleaning, 5) testing, 6) modernization, 7) replacement, and 8) rescue. SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 7 4.3.2 Determination of any additional factors and data to be considered 4.3.2.1 General In addition to the reason (see 4.1) and the subject (see 4.3.1) for the risk assessment, any additional factors that can modify or clarify the subject shall be determined, and any experience with similar products should be taken into consideration in the course of the assessment. 4.3.2.2 Life cycle of the subject being assessed 4.3.2.2.1 The intended life cycle is an important factor in determining the probability that a given event will occur. It does not, however, always come into play. If a standard is being written to address intrinsic safety, the life cycle need not be taken into account. EXAMPLE A safe gap can be defined by “a dimension not exceeding x”. This requirement is not related to time. Exceeding “x” is deemed to be unsafe. 4.3.2.2.2 Life cycle does have a role when considering the probability that a particular event will occur due to a component failure. In this situation, the life cycle of the system incorporating the component shall be considered. If, for example the system is to perform its function for 8 years, then the life of components shall at least match this to avoid a high probability of failure and, therefore, the occurrence of a given event. If, however, the component, through preventive maintenance, is replaced before failure occurs, the probability of the occurrence of a given event is low. EXAMPLE 1 If a component expected to perform its safety function no longer than 8 years is incorporated in a lift system that is expected to operate safely during a 20-year interval, the lift will do so only if the component is replaced with a new one in intervals of less than 8 years, as shown in Figure 2.
Key 1 time of system life cycle, 20 years 2 component life cycle, 8 years 3 time of replacement (prior to expected end of component life cycle end) Figure 2 — Replacement of components with a component life cycle shorter than the system life cycle EXAMPLE 2 If a component critical for lift safety could fail once, twice or thrice during the life cycle of a lift system, the probability of the failure of the component, as well as the probability of an unsafe condition occurring on the lift system, would be estimated as “C — occasional” when estimating the risk in accordance with 4.5.4 and Table C.2 of Annex C. If, however, there is a programme in place to regularly replace the component before the end of its lifetime, the probability of an unsafe condition occurring in the lift system would be estimated as “D — remote” or “E — improbable”, depending on the reliability of the component, as well as the reliability of the replacement programme. SIST EN ISO 14798:2013

ISO 14798:2009(E) 8 © ISO 2009 – All rights reserved 4.3.2.3 Information and data 4.3.2.3.1 Any available information and data that could assist in the qualitative and quantitative analysis should be taken into account. This includes accident and incident history, and causes and effects, which are relevant to the subject of the assessment or to similar products or procedures. 4.3.2.3.2 The absence of an accident history, a small number of accidents, or the low severity of the effects of the accidents should not lead to an automatic presumption of low risk. 4.3.2.3.3 Quantitative data can be used to supplement the data, based on the consensus of expert opinion derived from experience, as described in this International Standard. 4.4 Step 4 — Identification of scenarios: hazardous situations, causes and effects NOTE 1 In addition to the risk scenarios given in this subclause, Annex B and Annex F, further examples are provided in ISO/TS 22559-1. NOTE 2 Examples of hazards in Annex B are related to lifts. More general and comprehensive examples of hazards, hazardous situations and harmful events related to machinery in general, are provided in ISO 14121-1. 4.4.1 Hazard identification 4.4.1.1 The focal point of a scenario is the identification of hazards that could be associated with the subject being assessed. Table B.1 lists typical hazards that could be associated with lifts, including details and examples of the hazards. The list can be used as a starting point when formulating a scenario. EXAMPLE The risk assessment team can start by asking whether there is any situation in which people can be exposed to any type of hazard, for instance mechanical, electrical, fire or chemical. 4.4.1.2 A hazard may be inherent in the functionality of the lift system. EXAMPLE A lift car and counterweight, when moving adjacent to an open floor or stairway used by people, is an inherent hazard to people. A counterweight moving adjacent to the car inside the lift well is also an inherent hazard to the mechanic working from the top of the car. Both hazards and related situations are covered in Table B.1, item B.1.1 b), and Table B.2, item B.2.1 b). 4.4.1.3 In many cases, a hazard becomes obvious only after a scenario is formulated. Hazards that are not inherent to the functionality of the lift system include the following: a) hazards associated with the failure of the lift system, a component or a part of a lift or the malfunction of a safety-related system or component (see Table B.3, items B.3.1 and B.3.2); b) hazards associated with outside influences such as the environment, temperature, fire, climatic conditions, lightning, rain, wind, snow, earthquakes, electromagnetic phenomena (EMC), the condition of the building and its use (see Table B.3, items B.3.4 to B.3.6);
c) hazards associated with inappropriate procedures for the operation, use, service or cleaning of a lift or parts thereof, or other functions performed on a lift or parts thereof; hazards associated with the misuse of the system or process, or related to the disregard of ergonomic principles affecting safety (see Table B.3, item B.3.7). 4.4.2 Formulation of a scenario 4.4.2.1 Scenario The formulation of a scenario includes the identification of a hazard and the formulation of a hazardous situation, and its cause and effect. It is important to identify and record the hazard(s) before the formulation of the scenario proceeds. It is critical for a scenario to be formulated in the sequence of occurrence of each part of the scenario. SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 9 4.4.2.2 Hazardous situations All situations or other circumstances in which people (or property or environment) can be exposed to one or more hazards should be identified. This applies to all hazardous situations associated with the subject being assessed, throughout the life cycle of the subject (see 4.3). Table B.2 contains examples of hazardous situations in which people can be exposed to the specific types of hazards listed in Table B.1. Table B.2 can help the team (see 4.2) when formulating hazardous situations. 4.4.2.3 Causes All events that could occur in a hazardous situation and that can create the possibility for people to be exposed to a hazard should be identified. Table B.3 gives examples of causes that can create a possibility of exposure to specific types of hazard. 4.4.2.4 Effects 4.4.2.4.1 The effects that can result from a cause within a hazardous situation shall be identified. Harm may be part of such effects. 4.4.2.4.2 Table B.4 gives the main features of examples of possible effects. For the purposes of risk assessment, in certain cases a more explicit description of a possible effect might be needed in addition to the descriptive format given in Table B.4. EXAMPLE In the case of an effect of a person slipping and falling on the floor because it is slippery, the description of the effect as “slipping and falling on the floor” might be sufficient for the estimation of the level of severity of the effect, including harm. However, in the case of an effect involving “falling from a height”, a more detailed description, such as the height from which the fall occurs, might be needed for the purpose of estimation of the level of severity of the effect, including the harm as the part of the effect. 4.4.2.4.3 When it comes to the description of effects in terms of harm, the team may decide to expand the description of the effect by specifying the nature of possible harm using examples in Table B.5, before proceeding to the estimation of the level of severity of harm (see 4.5.3.1). NOTE Example 1 of Annex F illustrates two approaches to the description of effect and harm as part of the effect, for the purpose of estimation of the degree of severity. 4.4.3 Recording of scenario elements Annex F gives examples of identifying and recording the subject of the risk analysis, hazards and scenarios. It is not always necessary to list all the hazards before formulating relevant hazardous situations and harmful events because, in most cases, the description of the hazardous situation and its causes and effects states the type of hazard being considered. It is, however, important that all members of the risk assessment team (see 4.2) agree on the type of hazard, hazardous situation, and cause and effect, before the estimation of the risk elements and the risk evaluation proceeds. NOTE ISO/TS 22559-1 includes global, essential safety requirements for lifts that can be used to provide samples of scenarios in addition to the examples given in Annex F of this International Standard. 4.5 Step 5 — Risk estimation 4.5.1 General 4.5.1.1 Up to step 4 (see 4.4), the scenarios have been formulated, including the hazard, hazardous situation and cause, as well as the potential effects that can result in harm. The possibility of harm has been identified but the level of the risk of harm remains to be determined. The risk estimation process is used to establish the level of risk elements and hence, the level of risk. SIST EN ISO 14798:2013

ISO 14798:2009(E) 10 © ISO 2009 – All rights reserved 4.5.1.2 When determining elements of risk, and in particular, the probability of the occurrence of harm (see 4.5.4), only one lift shall be considered, rather than multiple installations of the same kind or the whole group of lifts. However, there are the following additional considerations. a) When the elements of risk for one lift are being determined, where appropriate, the risks related to a group of interconnected lifts should also be considered for inclusion in the scenario. EXAMPLE One moving escalator is feeding passengers onto a non-moving escalator (see also Example 4 of Annex F). b) When elements of risk for one lift are being determined, statistics and experience derived from multiple installations or the whole lift group may be used. EXAMPLE Statistics can indicate that out of 200 000 hydraulic lifts equipped with direct-plunger and in-ground cylinders, one incident per year occurs involving the lift car travelling at excessive speed or the lift car falling into the lift pit, due to the rupture of the cylinder. The probability of the occurrence of such an incident on a lift being analysed should be estimated as 1/200 000 per year or 1/10 000 during the 20-year life cycle of the lift. 4.5.1.3 Where a risk assessment team cannot reach consensus on the estimation of risk elements, the level of harm (see 4.5.3.1), or the level of probability (see 4.5.4.1), the scenario formulated in accordance with 4.4 should be re-examined for clarity and, if necessary, redefined (see also E.5). 4.5.2 Elements of risk 4.5.2.1 The risk associated with a particular scenario is derived from a combination of the following elements: a) severity of harm;
b) probability of the occurrence of that harm, which can be a function of 1) the frequency and duration of the exposure of persons to the hazard, 2) the probability of occurrence of the scenario, and 3) the technical and human possibilities to avoid or limit the harm. 4.5.2.2 The elements are shown in Figure 3. Further details on elements of risk and the process of estimation of the level of severity of the possible harm and the level of probability of the occurrence of that harm are given in 4.5.3 and 4.5.4. Ultimately, the level of risk is determined in accordance with 4.5.6 and evaluated in accordance with Clause 5. NOTE In many cases, these elements cannot be exactly determined, but can only be estimated. This applies especially to the probability of occurrence of possible harm. Risk
Severity
Probability of occurrence of the harm related to the considered hazard is a function of the possible harm that can result from the considered scenarioand which can be a function of a) the frequency and duration of the exposure, b) the probability of harmful events, and c) the possibility of avoiding or limiting the harm. Figure 3 — Elements of risk SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 11 4.5.2.3 In determining the level of probability of occurrence of the harm, it is essential to consider the combined probability of the occurrence of the hazardous situation, the cause and the effect. In determining the level of severity, only the severity of the effect (harm) is to be considered. NOTE See Annex A. 4.5.3 Severity of harm 4.5.3.1 For the purposes of this risk assessment process, the level of severity of harm that can occur in a scenario should be estimated by considering possible effects on human life, property, or the environment, depending on the reason (see 4.1) and the subject (see 4.3) of the risk assessment, as being one of the following (see details in Table C.1): a) level 1 – high; b) level 2 – medium; c) level 3 – low;
d) level 4 – negligible. NOTE It can be necessary to modify the definitions of levels of severity given in Table C.1, depending on the reason for, and the subject of, the risk assessment (see 4.1 and 4.3). 4.5.3.2 When estimating the level of harm, the following should be taken into account: a) the nature of what is affected, in terms of 1) persons, 2) property, 3) environment, and 4) other factors as appropriate;
b) the extent of harm that could occur on a lift to 1) one person, and 2) several persons. 4.5.4 Probability of occurrence of harm 4.5.4.1 Levels of probability The probability of occurrence of harm can be estimated by taking into account the factors listed in 4.5.4.2 to 4.5.4.4. For this risk assessment methodology, the level of probability of occurrence of harm should be estimated as one of the following (see details in Table C.2): a) level A – highly probable; b) level B – probable; c) level C – occasional; d) level D – remote; e) level E – improbable;
f) level F – highly improbable. SIST EN ISO 14798:2013

ISO 14798:2009(E) 12 © ISO 2009 – All rights reserved 4.5.4.2 Probability of occurrence of a scenario When estimating the probability of occurrence of a harmful event (cause and effect) and of persons being in hazardous situations when the event occurs, the following factors can be useful: a) reliability of the lift components and the lift system as a whole (see 4.5.5.1); when assessing a process, such as servicing a lift or training service mechanics, the reliability and effectiveness of such processes should be considered; b) statistical data; c) accident history; d) history of the nature and degree of harm;
e) comparison with similar lifting devices, or components, or processes. NOTE 1 A cause that triggers a harmful event can be of technical, natural, or human origin. NOTE 2 When estimating the probability of an occurrence, the regional statistical data can be taken into account, because the probability can be influenced by regional practices and regulations, such as those related to installation, maintenance, periodic testing and inspection of lift systems. 4.5.4.3 Frequency and duration of exposure to hazard When estimating the probability of the occurrence of harm, the following factors should be considered. a) The exposure of all persons working on or using the lift to the hazards relevant to a specific lift situation or event should be considered. The exposure of lift users or mechanics should be estimated in relation to one lift, not to multiple lifts (see 4.5.1.2). b) Exposure and duration can be continuous. EXAMPLE A hazard that can have the effect of passengers tripping or falling when entering or leaving the lift car, exists even on lifts with perfectly level car-to-landing door sills. c) Hazardous situations are always present, but exposure to a hazard can be very infrequent and of short duration, which implies a lower level of probability. EXAMPLE Relative movement of lift parts inside a lift well can present hazards to mechanics working on the top of the lift car, which could cause shearing and crushing effects. However, exposure to these hazards is infrequent and of short duration, because the mechanic works infrequently on the top of the car of a lift and because the car does not always move when the mechanic is on the top of the car. The possibility of harm to the mechanic exists only while the car is in motion, and only if the mechanic’s body parts protrude beyond the perimeter of the top of the car. The mechanic’s training and hazard awareness (see 4.5.4.4) can certainly reduce probability of the event and effect. d) Exposure can also be less frequent, but the duration can vary. EXAMPLE If the strength of a landing door or its components is not sufficient to withstand any foreseeable misuse, such as a person hitting the closed door and breaking through when the car is away from the landing, there is a risk of a door breaking and a person falling into the well. Simultaneously, the person is exposed to the hazard with the possible effect of falling into the well and suffering serious harm. However, if the entrance remains unprotected after the door has been dislodged, the hazardous situation continues to exist, and potential users and passers-by are continuously exposed to the hazard of falling into the well. e) In general, when estimating the frequency and duration of exposure, all relevant factors should be considered, such as the need for, and frequency of access to, potentially unsafe locations and the time spent therein. EXAMPLE A comparison can be made between access into the lift well for the purpose of servicing the lift and access to the lift car for the purpose of transportation. SIST EN ISO 14798:2013

ISO 14798:2009(E) © ISO 2009 – All rights reserved 13 4.5.4.4 Possibilities of affecting, avoiding or limiting harm When estimating the probability of occurrence of harm, the following elements should be taken into account: a) who the users of the lift are, whether 1) members of the general public, including people of all ages, persons having physical disabilities, etc., or 2) trained goods handlers, or trained fire-fighters, who are aware of specific risks; b) who the persons who will perform any work on the lift are, whether 1) skilled mechanics, 2) inspectors, 3) authorized persons with limited knowledge of the lift installation, or 4) unskilled persons; c) whether all necessary resources are given to persons in 4.5.4.4 a) and b) to assist them in avoiding or limiting harm, such as 1) necessary training, work procedures and experience, 2) control over car movement, 3) means of risk awareness, such as warning signs and indicating devices, 4) adequate working space, and 5) procedure and means for escape from the hazardous situation; d) whether all human factors have been adequately considered, such as 1) interaction of persons with the lift equipment, 2) interaction between persons, typically when performing complex servicing tasks, 3) psychological aspects, suc
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