Laser safety fortresses can be dangerous

Abstract

Laser Safety assessments of systems and the consequential control methods are mostly dominated by the direct optical radiation hazard. The general work place safety environment now has an all hazards culture which looks at all equipment including laser systems as completely self-contained and inherently safe. A mismatch of hazard perception and safety solutions gives rise to typical families of laser process associated hazards which is the region where fatalities and major injuries occur. This can, for example, be highlighted with a ‘Fortress Approach’ to laser safety, in which containment of the radiation dominates the control engineering and fails to deal with a range of other process generated hazards and the fortress now contains as well as concentrates these hazards often leading to serious long term injury and death.The perception of Laser Safety has not really changed in the last 40 years, neither have the attitudes to tackling Laser Safety issues, consequently the protection strategy is dominated with the requirement of user goggles. This approach is generally produced as a consequence of subject specific specialists not appreciating the wider safety problems. This has little influence on improving the overall safety culture in this sector. In contrast general safety culture has in the last 15 years harnessed a more progressive hazard and risk based approach. Laser radiation safety remains fixed around the Maximum Permissible Exposure concept (MPE)Perceptions prompt behaviour, and repeated behaviours become habits and take on attitudinal labels. Traditional measurement tools used for behavioural safety have a major limitation. That is, they focus on behaviours that are relevant only to those people who have problems doing them regularly, e.g. working with laser safety goggles on.A lack of relevance, increases the chances of people perceiving low value in the process, and can decrease participation in it.Safety culture improvement can be better understood by using a model to represent the process. Loughborough University in conjunction with public health England have identified a process which seeks to identify the hazards associated with; the laser, the beam delivery, the laser process, the environment and finally all people involved.It is usually the process with which the laser is involved/initiating, which determines the complete hazard family associated with the laser process. The laser is normally used within a process to monitor target activity, control the environment or process or induce some material/energy interaction. An alternative way of categorising the process is to examine the material/energy interaction. Thus a low level of interaction means the process is really determined by the detector limits, a median level is where energy absorption is beginning to interact with the material and a high level of absorption is where phase changes in the material (such as heating, melting, evaporation and plasma) take place. The process therefore determines the family hazards likely to be generated the interaction region which can then suggest the Hazard families likely in the other branches of i.e. beam delivery, laser, environment and people. The implementation of a fortress containment system either around the immediate equipment or as part of a larger room enclosure often fails to recognise these additional hazards and offering containing leads to further catastrophic consequences such as fire and explosions…Laser Safety assessments of systems and the consequential control methods are mostly dominated by the direct optical radiation hazard. The general work place safety environment now has an all hazards culture which looks at all equipment including laser systems as completely self-contained and inherently safe. A mismatch of hazard perception and safety solutions gives rise to typical families of laser process associated hazards which is the region where fatalities and major injuries occur. This can, for example, be highlighted with a ‘Fortress Approach’ to laser safety, in which containment of the radiation dominates the control engineering and fails to deal with a range of other process generated hazards and the fortress now contains as well as concentrates these hazards often leading to serious long term injury and death.The perception of Laser Safety has not really changed in the last 40 years, neither have the attitudes to tackling Laser Safety issues, consequently the protection strategy is dominated ...