Adequate control of substances hazardous to health
We were called to a workshop based in Wednesbury, that specialised in the manufacturing of intrinsically safe electrical equipment. Our client was concerned about the concentrations of hazardous substances, which his employees were being exposed to during their working day.
The site consisted of one open plan unit, welfare facilities and offices. There were approximately 23 permanent employees and their working day starts at 8 am and finishes at 5pm. So the exposure time is typically 7 hours and 40 minutes. Employees that work in the linishing area, use hand held air powered linishers. This exposes employees to respirable and inhalable dust particles however no respiratory protective equipment is currently used during these tasks. Although the working area is equipped with a local exhaust ventilation system in order to minimise exposure to employees.
The welding area is equipped with an enclosed welding booth which is fitted with a downdraft extraction table. In this area employees are tasked with welding mainly stainless steel components using a welding method known as TYG. Employees working in the machining area are responsible for supervising CNC metal and polymer fabrication machines. These employees are likely to be exposed to oil based metal working fluids and polymer dust.
How are samples of hazardous substances collected?
We collected samples of airborne particulates using Casella and Gillian Personal samplers. Samples for inhalable and respirable dusts were collected using IOM sampling heads fitted with QMA filters (25mm, 1.6µm) and respirable foam plugs. Lastly samples for water based metal working fluids were collected using 7-hole sampling head fitted QMA filters (25mm, 1.6µm)
Are employees at risk of exposure to hazardous substances?
The answer is no. The result of our air monitoring suggests that the employees are unlikely to be exposed to levels of respirable dust, welding fumes and oil mist above the workplace exposure limits (WELs). Although employees are not currently at risk, we recommend that the extraction capacity of the downdraft welding tables are improved as the current extraction is considered inadequate. This could be indicating that the extraction system on the downdraft welding tables is deteriorating and therefore needs repairing or replacing in the near future. It is important that all machinery is regularly serviced and replaced when necessary.
All employees should be trained on health risks from hazardous substances in the workplace, control measures, their used and maintenance. They should be provided with regular refreshers training at least once a year. Employees should also receive adequate training on the machinery in the workshop so that it is being used effectively. This training should also be updated regularly and when any new machinery is introduced to the workshop.