Dust Control Handbook for Industrial Minerals Mining and Processing

soiled with product, it is then tracked everywhere the worker goes until it either all falls off orthe boots are cleaned. Figure 8.13 shows product tracked onto the floor of a piece of mobileequipment. It is easy to understand the amount of dust that can be generated when this level ofmaterial is accumulated on the floor.Figure 8.13. Product tracked onto the floor of a piece of mobile equipment from dirty work boots.In cases where a substantial amount of dust and product gets tracked into a work area,housekeeping should be performed on a daily or shift basis. In other cases where thecontamination is not as great, housekeeping could be done on a more infrequent basis, but in anycase, it is critical that this contamination is dealt with to minimize the source of dust to workers.One strategy that was tried and shown to be effective in reducing the amount of dust generatedfrom dirt and product on the floor was through the use of sweeping compounds. A study wasconducted to determine the effectiveness of using a gritless, nonpetroleum based sweepcompound in a number of enclosed cabs [NIOSH 2001]. Figure 8.14 shows the averagerespirable dust concentrations measured inside two enclosed cabs for three to five shifts for bothtest conditions (baseline and sweep compound). The respirable dust levels were reduced from3 30.18 and 0.68 mg/m to 0.07 and 0.12 mg/m , respectively, for these two drills. These resultsindicate that the sweeping compound had a positive effect on suppressing dust when it was ableto make direct contact with and bind up the dirt on the steel and rubber floor mats.It should be noted that before any sweeping compound is used, companies should examine theMaterial Safety Data Sheet (MSDS) to ensure there are no ingredients that would cause problemsin an enclosed area. The sweeping compound should also be changed and disposed of properlyonce it has reached a state where it is no longer containing the dust.Controls for Secondary Sources 219