ISO 11228-1:2021

INTERNATIONAL ISO
STANDARD 11228-1
Second edition
2021-10
Ergonomics — Manual handling —
Part 1:
Lifting, lowering and carrying
Ergonomie — Manutention manuelle —
Partie 1: Manutention verticale vers le haut, manutention verticale
vers le bas et manutention horizontale
Reference number
© ISO 2021
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Published in Switzerland
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Risk reduction for manual lifting or carrying tasks . 3
4.1 General . 3
4.2 Risk assessment (step model) . 3
4.2.1 Using the step model . 3
4.2.2 Recommended limit for manual lifting, lowering and carrying . 6
4.2.3 Cumulative mass of carrying . 9
4.3 Risk reduction . 10
4.4 Additional considerations . 10
Annex A (informative) Ergonomics approach to the design of lifting and carrying tasks .11
Annex B (informative) Reference mass determination .17
Annex C (informative) Assessment method for recommended limits for mass, frequency
and object position .19
Annex D (informative) Lifting index .27
Annex E (informative) Simplified model for RML and LI calculation .29
Annex F (informative) Multi-task manual lifting .31
Annex G (informative) Examples of manual handling of objects .42
Annex H (informative) Carrying.52
Annex I (informative) Exposure and risk: the basis for Table D.1 .55
Bibliography .61
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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
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ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
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www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 159, Ergonomics, Subcommittee SC 3,
Anthropometry and biomechanics.
This second edition cancels and replaces the first edition (ISO 11228-1:2003), which has been
technically revised.
The main changes to the previous edition are as follows:
— revision of the scope to include lowering;
— expansion of the risk estimation;
— expansion of Annexes A, B and C;
— addition of Annexes D to I to include updated information; expansions of the RNLE (revised NIOSH
lifting equation); more examples for lifting and carrying; detailed information on the scientific
background and recommended interpretation of the RNLE.
A list of all parts in the ISO 11228 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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Introduction
0.1  General
The ISO 11228 series establishes ergonomic recommendations for different dynamic manual handling
tasks. It provides information for designers, employers, employees and others involved in work, job and
product design. The ISO 11228 series provides information on the evaluation of static postures.
Disorders of the musculoskeletal system are common worldwide and one of the most frequent
disorders in occupational health. The risk-assessment model in this document allows the estimation
of the risk associated with a manual material handling task. It takes into consideration the hazards
(unfavourable conditions) related to manual handling tasks and the time spent performing them.
Unfavourable conditions can include factors such as the size and mass of the object being handled,
working posture (e.g. twisting, bending, overreaching), quality of grip on items, and the frequency and
duration of manual handling. Any of these can, alone or in combination, lead to a hazardous handling
activity and increase the risk of musculoskeletal disorders. Accordingly, these factors are considered
when determining a recommended safe limit of the mass of objects being handled.
The method of determination of safe recommended limits in this document is based on the integration
of data derived from four major research approaches, namely the epidemiological, the biomechanical,
the physiological and the psychophysical approach.
0.2  The ergonomic approach
0.2.1  General
Ergonomics pursues the specific goals of optimizing human well-being and overall system performance.
This is achieved through contributions to the design and evaluation of tasks, jobs, production,
environment and systems in order to make them compatible with the needs, abilities and limitations
of people. It strives to design or to modify a work system to accommodate, as far as possible, a broad
range of people in order to meet the needs of workers with various characteristics, including people
with special requirements. Thus, the development of special solutions for individuals can be minimized.
Achieving these goals also contributes to organizational sustainability and social responsibility.
Manual handling tasks in the workplace occur within the context of work systems. Interactions of
humans with items, information, environment and other people must be taken into consideration when
designing or modifying tasks and work areas. The ergonomics approach can be used to prevent manual-
handling-related injuries from occurring by being used proactively in the design of processes, systems
or work organization, in addition to when modifications to existing systems are being considered.
The ergonomic approach considers tasks in their entirety, taking into account a range of relevant
factors including the nature of the task, the characteristics of objects handled, the working environment
and the individuals performing the task. It considers environmental conditions (e.g. lighting, noise,
temperature), as well as an individual’s characteristics and experiences. An individual’s characteristics
include physical and mental capabilities, skills, work techniques, behaviour and their perception of the
work environment and its social characteristics.
0.2.2  Organizational considerations
Work organization (e.g. task duration, job duration, recovery time, shift patterns) is a contributing
factor in the prevention or development of musculoskeletal disorders. For example, recovery periods
help to mitigate possible muscular fatigue and help to avoid the overuse of similar muscle groups over
the duration of the work shift. Job rotation, job diversification and job enlargement are all methods of
structuring the work to facilitate variation and recovery within the work period.
Work organization includes appropriate training of workers, including how to safely perform tasks,
how to recognize and respond to hazardous conditions in workplaces, and which procedures and
communication channels to use to report and correct hazards. Regularly and properly maintained
equipment and facilities contribute to safer work, including manual handling tasks. The selection of
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equipment and supplies which are appropriate for the workplace and task conditions helps to make
work demands safer.
0.2.3  Psychological health and safety and the ergonomics approach
The ergonomics approach considers the cognitive or psychological demands on humans, as well
as the psychosocial environment in which work takes place. Psychological response to work and
workplace conditions (psychosocial factors) has an important influence on mental, physiological and
musculoskeletal health. Psychosocial factors in the workplace include the design, organization and
management of work, work content, job complexity, job demands (cognitive and physical), job content
and the overall social environment (i.e. the context of work).
Undesirable psychosocial aspects of a job can include:
— little or no control over work methods or organization;
— high levels of attention and concentration required;
— poor use of skills;
— little or no involvement in decision-making;
— repetitive, monotonous tasks only;
— machine- or system-paced work;
— work demands perceived as excessive;
— payment systems which encourage working too quickly or without breaks;
— work systems that limit opportunities for social interaction;
— high levels of effort not balanced by sufficient reward (e.g. resources, remuneration, self-esteem,
status);
— no training and skill enhancement encouraged or supported;
— poor co-worker or supervisory support.
Many of the effects of these factors on workers occur via stress-related processes, which can in turn
have a direct effect on biochemical and physiological responses, which can increase the likelihood of
experiencing musculoskeletal injury. Thus, for the prevention of musculoskeletal disorders (MSDs),
these psychosocial stressors should be controlled in addition to the biomechanical risk factors. For
more information on the effects of the psychosocial stressors on MSDs, see References [63] to [66]. For
further information on psychological health and safety in the workplace, see References [1] to [42]
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