4 Hazard identification and risk assessment.
4.1 General
4.2 Layout design
4.3 Risk assessment
4.4 Hazard identification
4.5 Hazard elimination and risk reduction
4 Hazard identification and risk assessment
4.1 General
4.1.1
The operational characteristics of robots can be significantly different from those of other machines
and quipment, as follows:
a) robots are capable of high energy movements through a large operational space;
b) the initiation of movement and the path of the robot arm are difficult to predict and can vary, for example
due to changing operational requirements;
c) the operating space of the robot can overlap a portion of other robots' operating space or the work zones
of other machines and related equipment;
d) operators can be required to work in close proximity to the robot system while power to the machine
actuators is available.
4.1.2
It is necessary to identify the hazards and to assess the risks associated with the robot and its
application before selecting and designing appropriate safeguarding measures to adequately reduce the risks.
Technical measures for the reduction of risk are based upon the following fundamental principles:
a) the elimination of hazards by design or their reduction by substitution;
b) preventing operators coming into contact with hazards or controlling the hazards by achieving a safe state
before the operator can come into contact with it;
c) the reduction of risk during interventions (e.g. teaching).
4.1.3 The realization of these principles can involve:
a) designing the robot system to allow tasks to be performed from outside the safeguarded space;
b) the creation of a safeguarded space and a restricted space;
c) provision of other safeguards when interventions have to occur within the safeguarded space.
4.1.4 The type of robot, its application and its relationship to other machines and related equipment will
influence the design and the selection of the protective measures. These shall be suitable for the work being
done and permit, where necessary, teaching, setting, maintenance, programme verification and
troubleshooting operations to be carried out safely.
4.2 Layout design
The design of the robot system and cell layout is a key process in the elimination of hazards and reduction of
risks. The following factors shall be taken into account during the layout design process.
a) Establishing the physical limits (three dimensional) of the cell or line, including other parts of a larger cell
or system (integrated manufacturing system):
1) scale and origin for modelling the layout in design drawings;
2) location and dimensions of the components within available facilities (scale).
b) Workspaces, access and clearance:
1) identifying the maximum space of the robot system, establishing restricted and operating spaces,
and identifying the need for clearances around obstacles such as building supports;
2) traffic routes (pedestrian aisles, visitor routes, material movement outside the perimeter safeguarding
of the cell or line);
3) access and safe pathway to support services (electricity, gas, water, vacuum, hydraulic, ventilation)
and control systems;
4) access and safe pathway for service, cleaning, troubleshooting and maintenance purposes;
5) cables/other hazards for slips, trips and falls;
6) cable trays.
c) Manual intervention – the layout should be designed to allow tasks requiring manual intervention to be
performed from outside the safeguarded space. Where this is not practicable and when the intervention
requires powered movements of the machine(s), appropriate enabling devices shall be provided. The
enabling devices may be designed to control:
1) the whole robot cell;
2) a zone in the robot cell;
3) a selected machine or equipment within the cell.
NOTE See ISO 12100 for more information.
d) Ergonomics and human interface with equipment:
1) visibility of operations;
2) clarity of controls;
3) clear association of controls with robot;
4) regional control design traditions;
5) position of workpiece relative to the operator;
6) foreseeable misuse;
7) collaborative operation.
e) Environmental conditions:
1) ventilation;
2) weld spark.
f) Loading and unloading the workpieces/tool change.
g) Consideration of perimeter safeguarding.
h) Requirements for and location of emergency stop devices and possible zoning of the cell (e.g. local stops
or full cell stop).
i) Requirements for and location of enabling devices.
j) Attention to the intended use of all components.
The risk assessment shall determine the additional space required beyond the restricted space to define the
safeguarded space.
4.3 Risk assessment
4.3.1 General
Because a robot system is always integrated into a particular application, the integrator shall perform a risk
assessment to determine the risk reduction measures required to adequately reduce the risks presented by
the integrated application. Particular attention should be paid to instances where safeguards are removed
from individual machines in order to achieve the integrated application.
Risk assessment enables the systematic analysis and evaluation of the risks associated with the robot system
over its whole lifecycle (i.e. commissioning, set-up, production, maintenance, repair, decommissioning).
Risk assessment is followed, whenever necessary, by risk reduction. When this process is repeated, it gives
the iterative process for eliminating hazards as far as practicable and for reducing risks by implementing protective measures.
Risk assessment includes:
- determination of the limits of the robot system (see 4.3.2);
- hazard identification (see 4.4);
- risk estimation;
- risk evaluation.
4.3.2 Limits of the robot system
The integration of a robot system begins with the specification of its intended use and limits described in
ISO 12100, ISO 11161 and other applicable C level standards. This specification should include, for example:
a) use limits:
1) description of functions, intended use and reasonably foreseeable misuse;
2) description of the different user modes;
3) analysis of process sequences including manual intervention;
4) description of interfaces, tooling and equipment;
NOTE 1 It is advisable that the relevant C level standards for these devices be taken into account.
5) utility connections;
6) information supplied by the manufacturer, which is derived from the use of ISO 10218-1, including
applied measures for risk reduction;
7) required power supply and their appliances;
8) required or anticipated user skills (competency);
b) space limits (see 5.5 describing layout):
1) required machine movement range;
2) required space for installation and maintenance;
3) required space for operator tasks and other human intervention;
4) reconfiguration capabilities (ISO 11161);
5) required access (see 5.5.2);
6) foundations;
7) required space for supply and disposal devices or equipment;
c) time limits:
1) intended life limit of the machinery and its components (wear parts, tools, etc.);
2) process flow charts and timings;
3) recommended service intervals;
d) other limits:
1) environmental (temperature, use indoors or outdoors, tolerance to dust and moisture, etc.);
2) required cleanliness level for the intended use and environment;
3) properties of processed materials;
4) hazardous environments;
5) lessons learned, i.e. study and comparison, including available accident and incident reports, of
similar operations and systems.
NOTE 2 Other national standards and local codes can also provide important information on sources of power and
requirements for safe handling and installation.
4.4 Hazard identification
4.4.1 General
The list of significant hazards for robot and robot systems contained in Annex A is the result of hazard identification and risk assessment carried out as described in ISO 12100.
Further hazards (e.g. fumes, gases, chemicals and hot materials) can be created by specific applications
(e.g. welding, laser cutting, machining) and by the interaction of the robot system with other machines
(e.g. crushing, shearing, impact). These hazards shall be addressed on an individual basis with a risk
assessment for the specific application.
4.4.2 Task identification
In order to determine the potential occurrence of hazardous situations it is necessary to identify the tasks that
are to be carried out by operators of the robot system and its associated equipment. The integrator shall
identify and document these tasks. The user shall be consulted to ensure that all reasonably foreseeable
hazardous situations (task and hazard combinations) associated with the robot cell are identified, including
indirect interactions (e.g. persons having no tasks associated with the system but having exposure to hazards
associated with the system). These tasks include, but are not limited to:
a) process control and monitoring;
b) workpiece loading;
c) programming and verification;
d) brief operator intervention not requiring disassembly;
e) set-up (e.g. fixture changes, tool change);
f) troubleshooting;
g) correction of malfunction(s) (e.g. equipment jams, dropped parts, event recovery and abnormal
conditions);
h) control of hazardous energy (including fixtures, clamps, turntables and other equipment);
i) maintenance and repair;
j) equipment cleaning.
4.5 Hazard elimination and risk reduction
Having identified the hazards, it is necessary to assess the risks associated with the robot system before
applying appropriate measures to adequately reduce the risks. Measures for the reduction of risk are based
upon these fundamental principles:
a) the elimination of hazards by design or the reduction of their risk by substitution;
b) safeguarding to prevent operators coming into contact with hazards or to ensure the hazards are brought
to a safe state before the operator can come into contact with them;
c) the provision of supplementary protective measures such as information for use, training, signs, personal
protective equipment, etc.
The requirements contained in Clause 5 have been derived from the iterative process of applying risk
reduction measures, in accordance with ISO 12100, to the hazards identified in Annex A. The integrator shall
ensure that the risks identified in the risk assessment are adequately reduced by applying the requirements of
Clause 5. If risks are not adequately reduced, further risk reduction measures shall be applied until they are
adequately reduced.
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