TWI Industrial Member Report Summary 596/1997
By G J Carter and K Y K Chung
Welding fume is the subject of legislation limiting the concentration to which workers may be exposed by inhalation. Compliance with the regulations is presently verified by measuring personal exposure using national procedures which are applied on a national basis.
To ensure uniformity of exposure measurement within Europe, a European Standard has been drafted for sampling airborne particles and gases emitted during welding and allied processes. The Standard defines a test method for the gravimetric determination of exposure to welding fume and provides examples of samplers that may be used and how they might be positioned and secured in a worker's breathing zone. Advice is provided on sampling in the presence of other airborne particles (eg. grinding dust) and on the determination of exposure to individual fume constituents either by using the chemical analysis of the fume sampled or by assuming the fume analysis to be that supplied on a manufacturer's safety data sheet. Thus, the standard provides options in terms of the samplers and procedures used, but at the present time insufficient data are available to evaluate the effects of these options on the measurement of exposure.
Accordingly, work was performed to evaluate the effect of these sampling and procedural options during welding and grinding stainless steel,
with attention to the flux cored arc and metal active gas welding processes. It is expected that information obtained here will be considered by the appropriate European standardisation committee when the draft standard is reviewed.