Welding safely - Down draft benches
April 1st 2004 Employee safety in the workplace is an issue that should be a priority above all else in the eyes of the employer. This is especially the case when conducting potentially dangerous operations such as welding. The risks from welding vary from UV light exposure, hot sparks, fire hazards to gas and fume exposure.
Gas and fume exposure may not appear an immediate danger; however the long term health affects can be horrendous. Respiratory problems have been highlighted by the Control of Substances Hazardous to Health (COSHH) regulations as a serious risk in the workplace. Long term illnesses such as metal fume fever, asthma, systemic poisoning, siderosis and even cancer are potentially silent killers in the workplace, and all illnesses are commonplace among the welding fraternity.
To combat the potential dangers COSHH has laid out guidelines to promote good working practice and to reduce employee risk. As more companies are becoming safety conscious, employers are continually seeking a solution to fume extraction. Many workers fail to realise that smoke and fume from welding contains dust particles that can become lodged in the lung, making it imperative to protect the working zone from fumes. With workers breathing at a rate of 0.5m2 per second, COSHH states the equivalent volume needs to be extracted from the work zone via Local Exhaust Ventilation (LEV).
For an LEV to meet COSHH regulations, the extraction system must be tested every 14 months to ensure it meets the required standard. LEV is a common method of capturing dust and fume as employers continually put more emphasis on employee safety. When considering an LEV system for welding, a number of variables must be considered. Ian Minty director of IPM (Extraction), comments: When assessing a welding area, the whole operation needs to be taken into account such as the weld type and rod, the material being used and other less obvious points such as oil near or on the workpiece. Other points relate to whether the welder will move or be at a fixed workplace.
Minty continues: When considering a solution, a point often overlooked is that hot fumes and smoke tend to rise to between 4 and 6m then fall, causing damage to sensitive electronic equipment and more importantly causing a health risk to personnel.
With this in mind, workbenches are rapidly growing in popularity as a method of LEV. The bench clean systems are closer to the fume source and drag the fumes down and away from the worker as opposed to past the workers face. IPM workbenches are 240V and have a variable speed controller, which varies from 0.5 to 2m/s. The variable speed makes the bench suited for a number of operations in a range of industries other than welding.
The advantage the bench clean system has over the trunk system is that wherever the operator moves around the bench the extraction will be maintained at a constant level. A trunk arm will need to be moved as the operator moves, disrupting the employees working pattern. If a worker is welding in a number of positions or moving around a large jig or fixture, a trunk will be unable to gather the fumes from a number of locations, rendering it a less effective unit.
The workbench is also a versatile unit and can be moved around a shop floor with simplicity. This was recently proven at an IPM customer; it wanted to re-arrange its manufacturing facility. The workbenches were simply wheeled to a new location whereas ducting would have required dismantling and repositioning, which would not only have been costly but would have disrupted production.
Ian Minty concludes: Despite these advantages, IPM design and supply ducted systems, including hi- vac systems because a workbench is not always a practical solution for our clients where they carry out operations on vehicle bodies and other large components. More articles from IPM (Extraction) Ltd.: | 
