Slide 4 of 20
Notes:
In the UK, all suppliers of welding consumables are required to provide fume composition data for their products, i.e. the welding rods, wires etc used in the welding process. For each of the hazardous substances present in the fume, the data they provide on Material Safety Data Sheets (or MSDSs) is used to calculate the concentration below which its limit value will not be exceeded, using the equation shown here. The lowest of the resulting series of concentrations may then be used as a control limit for the welding fume concerned, unless of course if it is above the general welding fume limit value of 5 mg m-3. A simple gravimetric measurement of the fume concentration can then be made and compared with this control limit to determine whether a welder is being exposed to an excessive concentration of the most hazardous component of the fume.
