SIST EN 1005-5:2007

SLOVENSKI oSIST prEN 1005-5:2005

PREDSTANDARD
maj 2005
Varnost strojev - Človeške fizične zmogljivosti - 5. del: Ocena tveganja
rokovanja z veliko pogostostjo ponavljanja
Safety of machinery - Human physical performance - Part 5: Risk assessment for
repetitive handling at high frequency
ICS 13.110; 13.180 Referenčna številka
oSIST prEN 1005-5:2005(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD
DRAFT
prEN 1005-5
NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2005
ICS
English version
Safety of machinery - Human physical performance - Part 5:
Risk assessment for repetitive handling at high frequency
Sicherheit von Maschinen - Menschliche körperliche
Leistung - Teil 5: Risikobewertung für kurzzyklische
Tätigkeiten bei hohen Handhabungsfrequenzen
This draft European Standard is submitted to CEN members for second enquiry. It has been drawn up by the Technical Committee
CEN/TC 122.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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 Management Centre has the same
status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 1005-5:2005: E
worldwide for CEN national Members.

---------------------- Page: 2 ----------------------
prEN 1005-5:2005 (E)
Contents
Foreword.3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .6
4 Abbreviations.7
5 Requirements.7
6 Information for use .16
Annex A (informative) Identification of technical action .17
A.1 Examples for identifying and counting technical actions.18
Annex B (informative) Posture and types of movements.23
Annex C (informative) Force.28
C.1 General.28
C.2 Procedure 2 – A psychophysical approach using the CR-10 Borg scale.29
Annex D (informative) Association between the OCRA index and the occurrence of Upper Limbs
Work-related Musculo-Skeletal Disorders (UL-WMSDs): criteria for the classification of results
and forecast models.31
D.1 General.31
D.2 OCRA Index values, exposure areas and consequent actions.33
Annex E (informative) Influence of recovery periods pattern and work time duration in determining
the overall number of reference technical actions within a shift (RTA) and, consequently, the
OCRA index.35
Annex F (informative) An application example of risk reduction in a mono-task analysis .37
F.1 Foreword.37
F.2 General: technical characteristics of the task .37
F.3 Hazard identification .38
F.4 Method 1 .39
F.5 Method 2 .39
Annex G (informative) Definition and quantification of additional risk factors .54
Annex H (informative) Risk assessment by Method 2 when designing “multitask” jobs.55
H.1 OCRA index calculation when two or more repetitive tasks should be assessed .55
H.2 An application example: assessing repetitive tasks at a machinery .56
H.3 Multi-tasks analysis.62
H.4 Conclusion .65
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of EU Directive 98/79/EC .66
Bibliography .67

2

---------------------- Page: 3 ----------------------
prEN 1005-5:2005 (E)
Foreword
This document (prEN 1005-5:2005) has been prepared by Technical Committee CEN/TC 122 “Ergonomics”, the
secretariat of which is held by DIN.
This document is currently submitted to the second CEN Enquiry.
This document has been prepared under a mandate given to CEN by the European Commission and the European
Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this document.
EN 1005 consists of the following Parts, under the general title "Safety of machinery – Human physical
performance":
 Part 1: Terms and definitions;
 Part 2: Manual handling of machinery and component parts of machinery;
 Part 3: Recommended force limits for machinery operation;

1)
 Part 4 : Evaluation of working postures and movements in relation to machinery;
 Part 5: Risk assessment for repetitive handling at high frequency.


1) Under preparation
3

---------------------- Page: 4 ----------------------
prEN 1005-5:2005 (E)
Introduction
Within the life cycle of a machine from construction to dismantling, various machine-related actions require
repetitive handling at high frequency, which causes musculoskeletal strain and the risk of fatigue, discomfort and
musculoskeletal disorders. The designer of a machine should seek to minimise these health risks by taking into
account a variety of risk factors including the frequency of actions, the force, postures, durations, lack of recovery
and other additional factors.
The risk assessment method in this standard gives guidance to the designer how to reduce health risks for the
operator.
This standard is written in conformity with EN 1050 and gives the user a guidance for hazard identification for harm
through musculoskeletal overload and tools for qualitative and, to an extent, a quantitative risk assessment. The
risk assessment tools also indicate how to achieve risk reduction. This standard does not deal with risks related to
accidents.
The recommendations provided by this standard are based on available scientific evidence concerning the
physiology and epidemiology of manual work. The knowledge is, however, scarce and the suggested guidelines
are subject to changes according to future research. In accordance with the rules for CEN/CENELEC-standards
Part 2 clause 4.9.3.
This European Standard is a type B standard as stated in EN 1070.
The provisions of this document can be supplemented or modified by a type C standard.
This standard is not applicable to machinery, manufactured before the date of publication of this document by CEN.
NOTE For machines which are covered by the scope of a type C standard and which have been designed and built
according to the provisions of that standard, the provisions of that type C standard take precedence over the provisions of this
type B standard.
4

---------------------- Page: 5 ----------------------
prEN 1005-5:2005 (E)
1 Scope
This European standard presents guidance to the designer of machinery or its component parts and the writer of
C-standards in assessing and controlling health and safety risks due to machine-related repetitive handling at high
frequency.
This standard specifies reference data for action frequency of the upper limbs during machinery operation, and it
presents a risk assessment method intended for risk reduction option analysis.
This standard applies to machinery for professional operation by the healthy adult working population. This
standard is not applicable for upper arm elevation above shoulder height.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references,
only the edition cited applies. For undated references, the latest edition of the referenced document (including any
amendments) applies.
EN 614-1, Safety of machinery - Ergonomic design principles – Part 1: Terminology and general principles.
EN 614-2, Safety of machinery - Ergonomic design principles – Part 2: Interactions between the design of
machinery and work tasks.
EN 1005-1, Safety of machinery - Human physical performance – Part 1: Terms and definitions.
EN 1005-2, Safety of machinery - Human physical performance – Part 2: Manual handling of machinery and
component parts of machinery.
EN 1005-3, Safety of machinery - Human physical performance – Part 3: Recommended force limits for machinery
operation.

2)
prEN 1005-4 , Safety of machinery - Human physical performance – Part 4: Evaluation of working postures in
relation to machinery.
EN 1050, Safety of machinery - Risk assessment.
EN 1070, Safety of machinery - Terms and definitions.
EN ISO 6385, Ergonomic principles in the design of work systems.
EN ISO 12100-1, Safety of machinery - Basic concepts, general principles for design – Part 1: Basic terminology,
methodology.
EN ISO 12100-2, Safety of machinery - Basic concepts, general principles for design – Part 2: Technical
principles and specifications.
EN ISO 14738:2002, Safety of machinery - Anthropometric requirements for the design of workplaces at
machinery.
ISO/IEC Guide 51, Safety aspects – Guidelines for their inclusion in standards

2) Under preparation
5

---------------------- Page: 6 ----------------------
prEN 1005-5:2005 (E)
3 Terms and definitions
Definitions used in EN and ISO standards referred to in this European standard are also valid for this standard.
Additional definitions specifically needed for this European standard are added below.
3.1
repetitive task
task characterized by repeated work cycles
3.2
non-repetitive task
task characterized by the presence of non-repeated work cycle
3.3
work cycle
sequence of technical actions that are repeated always the same way
3.4
cycle time
the time elapsing from the moment when one operator begins a work cycle to the moment that the same work cycle
is repeated (in seconds)
3.5
technical action
elementary manual actions required to complete the operations within the cycle, such as holding, turning, pushing,
cutting
3.6
repetitiveness
quality of task when a person is continuously repeating the same cycle, technical actions and movements in a
significant part of a normal workday
3.7
frequency
number of (technical actions) per minute
3.8
force
physical effort of the operator required to execute the operations related to the machinery
3.9
posture and movements
positions and movements of body segment(s) or joint(s) required to execute the operations related to the
machinery
3.10
recovery time
period of rest following a period of activity in which restoration of a muscle can occur (in minutes)
3.11
additional risk factors
risk factors which include other factors for which there is evidence of causal or aggravating relationship with work-
related musculoskeletal disorders of the upper limb, e.g. vibrations, local pressure, cold
6

---------------------- Page: 7 ----------------------
prEN 1005-5:2005 (E)
4 Abbreviations
For the purposes of this European Standards the following abbreviations apply.
Acronyms Legenda for abbreviations
NTC  Number of technical actions in the cycle
FCT  Foreseeable duration of the Cycle Time (in seconds)
FF  Foreseeable Frequency of actions per minute
RF  Reference Frequency of technical actions
CF  “Constant of Frequency” of technical actions per minute
Po Posture Multiplier
M
Re Repetitiveness Multiplier
M
Ad Additional Multiplier
M
Fo Force Multiplier
M
Rc Recovery Multiplier
M
Du Duration Multiplier
M
ATA  Number of Actual Technical Actions within a shift
RTA  Number of Reference Technical Actions within a shift
n  Number of repetitive task/s performed during shift
j  generic repetitive tasks
D  net Duration in minutes of each repetitive task
OCRA  OCcupational Repetitive Action
NPA  Number of Persons Affected by one or more UL-WMSDs
PA  Prevalence (%) of persons Affected
NEP  Number of Exposed Persons
MSDs  Musculo-Skeletal Disorders
UL-WMSDs Upper Limb Work-related Musculo-Skeletal Disorders
S.E.  Standard Error
5 Requirements
5.1 The application of standards relevant to this document
The designer shall first consider EN 614 (Part 1 and 2), EN 1005-3, prEN 1005-4, EN ISO 12100 (Part 1 and 2) and
EN ISO 14738.
5.2 General aspects
Machines and related tasks shall be designed in a way so that activities demanding high frequency can be
performed adequately with respect to the force required, the posture of the limbs and the foreseeable presence of
recovery periods. In addition machines and related tasks shall be designed to allow for variations in movements.
Additional factors (vibration, cold, etc.) have to be considered.
7

---------------------- Page: 8 ----------------------
prEN 1005-5:2005 (E)
The technical action is identified as the specific characteristic relevant to repetitive movements of the upper
extremities. The technical action is factored by its relative frequency during a certain time period.
When designing machinery and work tasks, the designer shall ensure that the following ergonomics characteristics
of well-designed work tasks are implemented. These characteristics take into account the differences and dynamic
characteristics of the intended operator population, and shall be considered by designing machinery and machinery
related work tasks in interaction.
Thus, in design process the designer shall also (see EN 614-2):
a) avoid overload as well as under load of the operator, which may lead to unnecessary or excessive strain,
fatigue or to errors. Frequency, duration and intensity of perceptual, cognitive and motor activities shall be
designed so as to avoid these consequences
b) avoid repetitiveness for the operator, which may lead to unbalanced work strain and thus to physical disorders
as well as to sensations of monotony, satiation, boredom or to dissatisfaction.
Short work cycles should therefore be avoided. The operator shall be provided with an appropriate variety of tasks
or activities. If repetitive task cannot be avoided:
1) cycle time shall not be determined solely on the basis of average time measures or estimated under
normal conditions;
2) allowances shall be given for deviations from normal conditions;
3) very short cycle times shall be avoided;
4) opportunities shall be given to the operator to work at his/her own pace, rather than at set pace;
5) working on moving objects shall be avoided.
In this standard risk assessment in relation to physical overload during repetitive handling is described.
5.3 Risk assessment
The “frequency of upper limbs action“ is related to other risk factors such as force (the greater the force, the lower
the frequency), posture (the greater the joint excursion, the longer the time necessary to carry out an action) and
recovery periods (if well distributed during the shift, they increase the recovery of muscular function).
Some additional factors can increase the need for force (awkward tools or gloves) or cause damage to muscles,
tendons and vessels (vibration, compression, cold surfaces).
Data from recent epidemiological studies on workers exposed to repetitive movements of upper limbs allow, among
others, designers to forecast from exposure indexes the occurrence of the consequences for Upper Limbs Work-
related Musculoskeletal Disorders (UL-WMSDs) [10, 31, 32, 33]. Annex D describes a method of determination [5].
The acceptable situation occurs when the exposure index (OCRA) corresponds to a forecast of occurrence of
MSDs as observed in a working population not exposed to occupational risks for the upper limbs [4, 11, 15].
When repetitive handling is unavoidable then a risk assessment and risk reduction approach should be adopted. In
accordance with ISO Guide 51 and EN 1050, this should follow a four-step approach: hazard identification, risk
estimation, risk evaluation and risk reduction.
It is required to simulate tasks at least once by actual users with a full-size model/prototype of the machinery or the
machinery itself (refer to EN 614-1, ergonomic task 'evaluate with users'; see also prEN 1005-4 clause 4.2
‘Guidance towards risk assessment’).
The following procedure should be adopted when conducting a risk assessment of machinery design involving
repetitive handling (Figure 1).
8

---------------------- Page: 9 ----------------------
prEN 1005-5:2005 (E)

Figure 1 — Risk assessment model
The first stage of the risk assessment is to identify whether hazards exist which may expose individuals to a risk of
injury. If such hazards are present, then a more detailed risk assessment may be necessary. When determining a
risk assessment, consideration should be given to the following risk factors:
a) Repetitiveness:
Repetitive movements should be avoided within a task. As the movement frequency increases and/or the cycle
duration decreases, the risk of injury increases. Frequent repetitive movements giving rise to a risk of injury
may vary depending on the context of the movement pattern and the individual.
b) Force:
Tasks should involve smooth force exertions, avoiding sudden or jerky movements. Handling precision
(accurate picking and placement), the type and nature of the grip may introduce additional muscular effort.
9

---------------------- Page: 10 ----------------------
prEN 1005-5:2005 (E)
c) Posture and movement:
Work tasks and operations should provide variations to the working posture; both whole body postures and
movement of specific limbs. The work tasks should avoid extreme ranges of joint movement and there is a
need to avoid prolonged static postures. Complex postures involving combined movements (e.g. flexed and
twisted) may present greater risk.
d) Sitting restricts overall movement of the body, particularly those of the lower leg and back. This may lead to
increased and complex loading of the back and upper extremities. Standing for prolonged periods of time often
results in pain/discomfort in the legs and lower back, and may lead to venous pooling in the legs. Whenever
possible, workers should be given the option to vary between sitting and standing.
e) Duration and insufficient recovery:
Duration can be broken down in a number of ways, i.e. task duration, job duration, and work shift duration. The
opportunity for recovery or rest can fall within each of these work periods. Insufficient time for the body to
recover between repetitive movements (i.e. lack of recovery time) increases the risk of injury.
f) Additional risk factors:
The following list should be considered to find out if the risk related to repetitive handling is increased due to
additional risk factors:
1) Object characteristics (e.g. contact forces, shape, dimensions, coupling, object temperature)
2) Vibration and impact forces
3) Environmental conditions (e.g. lighting, climate, noise)
4) Individual and organisational factors (e.g. skills, the level of training, age, gender, health problems,
pregnancy)
5.3.1 Hazard identification
If the following conditions are satisfied there is no hazard:
 The task is not characterized by cycles
 The task is characterized by cycles, but perceptual or cognitive activities are clear prevalent and upper limb
movements are residual.
For all the machinery/task combinations in which cyclic manual activities are foreseen, risk estimation shall be
applied.
For each manual task to be performed on machinery the designer shall:
 identify and count the technical actions (for each upper limb) needed to carry out the task (NTC);
 define the foreseeable duration of the cycle time (FCT);
 consider the foreseeable duration and frequency of recovery periods;
 consider the possibility of rotation on different tasks, when designing a machinery e.g. in the context of an
assembly line.
An evaluation model will be presented in 5.3.2 (Method 1) and 5.3.3 (Method 2).
When the characteristics described in Method 1 are fully and simultaneously present, it is possible to affirm that risk
exposure to repetitive movements at high frequency is acceptable.
Where one or more of the listed characteristics for the different risk factors are not satisfied, the designer shall use
a more detailed evaluation (Method 2, 5.3.3).
10

---------------------- Page: 11 ----------------------
prEN 1005-5:2005 (E)
5.3.2 Risk estimation and simple evaluation of machinery related repetitive handling at high frequency
(Method 1)
5.3.2.1 Check of the risk factors
The designer shall check if, considering the main risk factors (force, awkward postures and movements,
repetitiveness, frequency of technical actions, additional factors), for each upper limb, the following conditions are
satisfied:
a) Absence of force, or use of force in accordance with the criteria regarding the recommended force limits as
reported in EN 1005-3.
b) Absence of awkward postures and movements considering the same conditions exposed in prEN 1005-4 as
summarized below:
1) The upper arm postures and movements are in the range between 0° and 20° (Zone 1 in Figure 6,
prEN 1005-4);
2) The articular movements of the elbow and wrist do not exceed 50 % of the maximum articular range [9],
(Table 1 and Annex B);
3) The kinds of grasp are “power grip”, or “pinch lasting no more than 1/3 of the cycle time”, (Table 1 and
Annex B). [4, 7, 10].
c) Low repetitiveness.
This is true if [38, 39]:
1) The cycle time is more than 30 seconds [19].
1) The same kinds of action are not repeated for more than 50 % of the cycle time [19].
d) Frequency of technical actions for both upper limbs is less than 40 actions per minute. If the frequency is
greater than 40 actions per minute for at least one upper limb then move on to Method 2.
In order to compute the frequency of actions/min (see annex A for identification of technical action), use the
following formula:
NTC ⋅ 60
FF = (1)
FCT
where:
FF is the foreseeable frequency of actions per minute;
FCT is foreseeable duration of the cycle time in seconds;
NTC is the number of technical actions (for each upper limb) needed to carry out the task.
e) Absence of additional factors (physical and mechanical factors).
The task should not include hand/arm vibration, shock (such as hammering), localized compression on
anatomical structures due to tools, exposure to cold, use of inadequate gloves for grasping etc. [4, 7]
(Annex G).
5.3.2.2 Final estimation and evaluation of machinery design by Method 1
When every condition shown in 5.3.2.1, points a, b, c, d, e are satisfied for each upper limb, the exposure is
acceptable. If one or more conditions mentioned in Method 1 are not met, the designer shall analyse in more detail
each risk factor that interferes with the frequency of actions by Method 2.
11

---------------------- Page: 12 ----------------------
prEN 1005-5:2005 (E)
5.3.3 Detailed risk assessment of machinery related repetitive handling at high frequency: risk reduction
and risk reduction option analysis (Method 2)
5.3.3.1 Evaluation of acceptable frequency of actions when one or more risk factors are present
If one or more conditions defined in Method 1 are not satisfied, the designer shall analyse in more detail each risk
factor that has an impact upon the frequency of actions. Since different risk factors can be present to a greater or
lesser extent, and in a variety of combinations, then different levels of risk can be expected.
The level of risk is assessed with reference to the OCRA method [8, 10, 30]. The OCRA index, when assessing a
single repetitive task in a shift (mono task job), is given by the ratio between the foreseeable frequency (FF) of
technical actions needed to carry out the task, and the reference frequency (RF) of technical actions, for each
upper limb (see Annex A for identification of technical action). This is a particular procedure for mono task jobs. For
multitask jobs see Annex H.
In this context:
FF
OCRA index =
RF
The foreseeable frequency (number per minute) of technical actions needed to carry out the task (FF) is given by
the following formula:
NTC ⋅ 60
FF =
FCT
where:
FCT is foreseeable duration of the cycle time in seconds;
NTC is the number of technical actions (for each upper limb) needed to carry out the task during one
cycle.
The following formula calculates the reference frequency (number per minute) of technical actions (RF) on a work
cycle base:
RF = CF × Po × Re × Ad × Fo ×()Rc × Du
M M M M M M
where:
CF   = “constant of frequency” of technical actions per minute = 30
Po ; Re ; Ad ; Fo = multipliers for the risk factors postures, repetitiveness, additional, force.
M M M M
Rc = multiplier for the risk factor “lack of recovery period”
M
Du   = multiplier for the overall duration of repetitive task (s) during a shift.
M
When designing a machinery related task, evaluate reference frequency of the technical actions within a work cycle
that is representative of the task under examination. The analyses shall include the main risk factors that the
designer can influence with the consequent choice of a specific multiplier for each risk factor. These multipliers will
decrease from 1 to 0 as the risk level increases. The risk factors and the corresponding multiplier, influenced by the
designer, are:
Awkward or uncomfortable postures or movements (posture multiplier) (Po ), see 5.3.3.1.1
M
High repetition of the same movements (repetitiveness multiplier) (Re ), see 5.3.3.1.2
M
Presence of additional factors (additional multiplier) (Ad ), see 5.3.3.1.3
M
12

---------------------- Page: 13 ----------------------
prEN 1005-5:2005 (E)
Frequent or high force exertions (force multiplier) (Fo ), see 5.3.3.1.4
M
The other factors considered in the formula (Rc × Du ) are generally out of the direct influence of the designer and
M M
consequently they will be considered, in this context, as a constant, reflecting a common condition of repetitive task
duration
...