[Examination of dust generated from a workplace where steel wire coil are unwound]

Analyses of constituents, measurement of concentrations, research of size distributions and scanning electron microscopic examinations were carried out to determine the type and amount of dust generated in a working environment where steel wire coils are unwound. In about a 700 m2 work area unit, stationary samplings, including A-sampling (24 points) and B-sampling (1 point), which are defined by the law, were carried out. The dust concentration was measured by a digital dust indicator. A low volume air sampler was used to determine the conversion factor of the values obtained by the digital dust indicator. Because the result of the dust level by A-sampling and B-sampling were 0.64 mg/m3 and 0.82 mg/m3 respectively, they can both be classified as Control Class 1. A proportion of less than 7 microns of the airborne dust made up about 15 to 20% (volume %) of the total dust in the working environments. Metallic dust and white dust were identified in the accumulated dust. By measuring with a X-ray diffractometry, it was determined that the metal dust constituent was Zn and the white dust constituent was Zn4CO3(OH)6.H2O. By a scanning electron microscopic examination, the scope of the particles was proven to be non-fibrous.