Diesel exhaust is considered to be a serious occupational hazard, particularly in areas that are not well ventilated because of the high concentrations which may be reached.
A simple method of the determination of the Respirable Combustible Dust (RCD) consists of acquiring a respirable dust sample on a 0.8 micron silver membrane filter. Upon receiving the filter, we place it in a muffle furnace and expose it to a temperature of 400°C for a minimum of 1.5 hours. The ashing temperature and the catalytic action of the silver membrane filter combine to make the carbon-based dust react with O2. The mass loss on ashing is considered to be the mass of RCD.
This method enables the determination of total respirable dust (TRD), respirable combustible dust (RCD) and respirable quartz dust, all from the same filter sample, saving both time and money.
Note: Sulphide minerals dusts will interfere with RCD determination