This part of ISO 15011 defines a laboratory method for measuring the emission rate of fume from arc welding. It also defines a method of collecting the fume for subsequent analysis and refers to suitable analytical techniques. The methods described are suitable for use with all open arc welding processes except tungsten inert gas (TIG) welding, which produces little fume. The emission rate method can be used to evaluate the effects of welding electrodes and wires, welding parameters, processes, shielding gases, test piece composition and test piece surface condition on fume emission rate. Following analysis of the fume collected, the effects of test parameters on fume composition can also be determined.