Photobiological hazards in shielded metal arc welding.

PURPOSE: Photobiological hazards caused by artificial optical radiation are assessed for the most commonly used arc welding technique, the SMAW (Shielded Metal Arc Welding), which operates with a hand-held system and is widely used both at occupational and domestic environments, expanding our previous investigation of a robotic arc welding process. METHODS: The complex exposure limits of the emitted blue and visible light, ultraviolet and infrared, are assessed through the European Directive 2006/25/EC, using three dedicated sensors set to measure irradiance from various typical welding procedures in the controlled environment (currents, electrodes, etc.) of a welding laboratory. In this sense, field measurements are employed, applying existing policies. Occupational limits are also applicable to the domestic welding. RESULTS: Apart from sub-minute overexposures, which were detected in every spectral band, overexposures in the order of one second were also observed at very close distances, which are common at complex working environments. Investigation of the initial welding procedure, which is often performed without the use of Personal Protective Equipment, revealed exposure of the order of the corresponding limit. CONCLUSIONS: Simulation of a 'bad' welding procedure revealed increased exposure, indicating the importance of training in the occupational environment. Concern for the exposure of near-by workers (working a few meters away from the welding point) is also crucial. Future work needs to incorporate more welding techniques and measurements from original workplaces, in order to set the basis for an integrated risk assessment and provide valuable information concerning occupational diseases.

Cold Spray: Over 30 Years of Development Toward a Hot Future.

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

Artificial Optical Radiation photobiological hazards in arc welding.

Occupational Health and Safety (OHS) is associated with crucial social, economic, cultural and technical issues. A highly specialized OHS sector deals with the photobiological hazards from artificial optical radiation (AOR), which is divided into visible light, UV and IR emitted during various activities and which is legally covered by European Directive 2006/25/EC. Among the enormous amount of sources emitting AOR, the most important non-coherent ones to consider for health effects to the whole optical range, are arcs created during metal welding. This survey presents the effort to assess the complicated exposure limits of the Directive in the controlled environment of a welding laboratory. Sensors covering the UV and blue light range were set to measure typical welding procedures reproduced in the laboratory. Initial results, apart from apparently justifying the use of Personal Protective Equipment (PPE) due to even subsecond overexposures measured, also set the basis to evaluate PPE's properties and support an integrated risk assessment of the complex welding environment. These results can also improve workers' and employer's information and training about radiation hazards, which is a crucial OHS demand.