This study has collected the control guidelines for nanomaterials in the workplace from United Kingdom, Japan and USA. The guidelines were carefully read, analyzed and compared for preparing the domestic “Nanomaterial control strategy in the workplaces (draft)” for the experts and scholars to discuss. The draft contains nine chapters, including the scope of nanomaterials, types and characteristics of engineered nanomaterials, risk assessment, methods of exposure assessment, exposure control, accidental spillage and release, disposal of nanomaterial waste, fire and exposure hazards, health surveillance. The small scale powder disperser (SSPD) was employed in this study for the powder dispersion experiment and results were compared with those of the rotating drum and the vortex shaker. Titanium dioxide, zinc oxide and silica were used as the test materials and the primary particle diameter was found to be either nano-size or submicrom-size for each material. The experimental results shows that the particle concentration generated from the SSPD was higher than the rotating drum and the vortex shaker, and the SSPD had the smaller NMD value than other two instruments.
Therefore, the SSPD have the highest powder dispersion efficiency. Furthermore, it was found that the aggregation of nano-size powder was more serious than submicrom-size powder. Titanium dioxide had the best powder dispersion, zinc was the second one and silica was the worst one.
By Comparing the filtration efficiency of the domestic HEPA filter with the foreign HEPA filter used in the industrial vacuum cleaner shows that the filtration efficiency of the foreign HEPA filter was high enough. Regardless of the particle size and the filtration flow rate, the collection efficiency was as high as 99%. However, the collection efficiency of the domestic HEPA filter was found to be from 20% to 60%. In the field for the particle concentration measurement, this study has proceeded the air sampling in the workplaces such as titanium dioxide mannufactoring factory, carbon nanotubes mannufactoring factory and toliet mannufactoring factory. We used different aerosol samplers and real-time instruments to measure the respirable aerosol and nanoparticle concentrations at different ventilation situations. It is found that the nanaoparticle concentration was not high in the three workplaces. In the titanium dioxide mannufactoring factory, the particle concentration has been affected by the ventlation fan. In addition, the source of nanoparticle was found not coming from the powder, which was coming from the forklift during the bagging operation.