In welding, electromagnetic fields, a natural part of the process, can also put welding professionals at risk – if taken lightly. The directive requires employers to ensure that their workers are not exposed to high levels of EMF. As a result, mandatory exposure limit values were established for all sectors on the basis of the recommendations issued by the International Community on Non-ionising Radiation Protection.
It is not, however, so straightforward as all that. Even if exposure limit values are given for the field induced by the human body, these are very difficult to assess. Thus, the directive also provides action levels of the field to which the worker is exposed, which can be measured directly. There are separate action levels for the body and limbs, and those levels are frequency-dependent. Therefore, the assessment should take into consideration the level of electromagnetic fields at various positions around the welder, as well as the frequency of the field.
Since most processes will generate multiple frequencies, is necessary to take into account the field of each frequency component.
In production, a range of typically identified processes is producing high levels of EMF. These include the following:
Some arc welding processes
Magnetic particle inspection
The magnitude of the field to which the welder is exposed will depend on the type of equipment, the welding parameters and the position of the welder. Therefore, every kind of equipment and operating procedure requires a separate assessment, which can be achieved by taking many measurements or by a complex calculation.
A specialised software called EMFWELD (developed by TWI, CEEMET and EWF) is available to use online (www.emfweld.eu) to make assessment simpler for health and safety officers and supervisors, requiring no download or installation, with a simple use. After the user enters details of the equipment, welding parameters and operator position, the software then calculates the EMF exposure based on an extensive database of results obtained from magnetic field waveforms from different processes and equipment. An assessment of the three action levels (low, high and limb) required in the directive is provided in the report obtained, which also includes exposure limits values.
EMFWeld provides an uncomplicated way of carrying out a complicated assessment, as it can be performed entirely online, with no need for software installation, which means it can even be used on the shop floor. Complex algorithms are used to generate detailed reports of EMF exposure levels based on simple parameters inputted by a user. As well as providing easily interpretable maps of the magnetic field strength around the welding equipment, each report also lets the user know what action, if any, is required to reduce exposure below the action levels.
EMFWELD has been developed by a consortium led by the European Federation for Welding, Cutting and Joining; the Council of European Employers of the Metal, Engineering and Technology-Based Industries; and TWI, a UK-based world leader in welding and joining research.
Also, EMFWELD generates a map of the field around the equipment, so it is easy to see where the exposure is below the action levels. The above chart for a resistance welding process shows that exposure is below the action levels where the operator is standing. It also indicates that if the operator is holding a component, the hand exposure will be exceeded up to 150mm from the electrodes. Also, for this equipment, exposure is higher at the side of the gun than in front of the electrodes.
Figure 1. Action levels compared with the EMF Directive
Where exposures exceed the action levels, often only small changes are required to bring the process into conformance. For example, moving slightly further away from the equipment or adjusting the position of handles and controls can produce a significant reduction in exposure.
Given the pervasive nature of electromagnetic fields in welding, most metalworking companies are now faced with the need to comply with the Directive and ensure the safety of their professionals. That means that health and safety officers and welding coordination personnel must be adequately equipped to respond to that need. For that to be possible, it is necessary to have a qualified workforce. At this moment a new professional profile is being developed through a European funded project called HS-EMFW with the purpose of fulfilling the actual market request for qualified personnel.
“currently, risk management in welding fabrication training is not harmonised, although some countries have already started looking into this area”
EWF manages an international harmonised qualification and certification system for welding and joining professionals since 1992, which is used in 46 countries and as such has the background for developing a qualification guideline for this new professional profile, the Electromagnetic Fields Health and Safety Officer in Welding (EFHSOW). This new qualification standard, being developed through a European Funded project called HS-EMFW, complies with the EU Directive requirements, responds to the market needs and it will be soon available across the EWF network comprised of 28 European countries and 18 non-European countries. Companies and professionals can have access to this qualification through EWF Authorised National Bodies.
Figure 2. Electromagnetic filed map around a welding equipment - www.emfweld.eu
This European qualification standard incorporates the common European tools (e.g. Learning Outcomes, EQF, ECVET), and complies with the Rules and Operating Procedures of the EWF Quality Assurance System.
Technologies and training
EWF is a pioneer in implementing a harmonised qualification and certification system for joining professionals. To keep its system responsive to the need created by the technological advance, EWF has been innovating in both training methodologies, and in the development of new technologies and uses for joining. In these projects, the need for qualified and aware personnel plays an important role. Two examples are the two Erasmus + projects EWF is currently involved in. One, called HSE-Joining, looking at the creation of Health, Safety and Environment training tools focused on joining. This focused on training personnel in the welding sector to ensure that they are aware of the hazards that joining professionals have to take into consideration. For example, hazards related to hot materials and spatter, working in confined spaces, toxic fumes, handling gas cylinders, infrared and ultraviolet radiation, vibrations, electromagnetic fields, electricity, noise, and cutting processes, while also looking into ergonomics. This project will also address the lack of environmental awareness.
Another project, called Risk Management in Welding Fabrication (RMWF), is developing a new training course to train the first group of specialists in this field. Currently, risk management in welding fabrication training is not harmonised, although some countries have already started looking into this area. Furthermore, there is a need to implement two standards which are intended to harmonise risk management at an international level (ISO 31000 and ISO/IEC 31010), thus creating the framework for optimised risk assessment and easier exchange of know-how between specialists in different countries.
Figure 3. HSE-JOINING project - http://hse-joining.eu/ - This publication reflects the views only of the author, and the Commission cannot be held responsible for any use which may be made of the information contained therein.
Through the project, participants will improve their competitiveness and employability on the labour market. By integrating the RMWF course into the EWF network and national educational systems in partner countries, the latter will be better aligned to the needs and opportunities offered by the labour market and closer linked to business and community.
The project's objectives are to develop a new training course and to train the first groups of specialists in the field of risk management in welding fabrication. Through these objectives, the project contributes to the recognition of skills and qualifications, making the first steps towards adding a new qualification. Once the project is finished, it is expected that the newly created course curricula be integrated into the EWF network, ensuring European recognition of the qualification. As a part of a life-long learning philosophy, the consortium will also develop an e-learning scheme for the training courses.
With the aim of connecting education with industry, through the contribution of its member organisations EWF has established a firm link to the local industry, providing knowledge and training as well as participating in research initiatives that address the most pressing questions and challenges in the field of joining technologies.