Particles produced by charge detonation: Measurement and analysis

Airborne particles are known to cause respiratory and cardiovascular problems. Although there are regulatory time-weighted limits for particle mass for working (e.g., Exposure Limit) and ambient environments (e.g., PM10, PM2.5), there are little data regarding the size distribution and concentration of particles produced by detonation of explosives that the defense and related industry needs. Several detonation experiments were conducted to determine the properties of aerosol particles generated by explosives that were prepared from conventional and nanophase materials. The initial number concentrations (∼ 10 ⁶-10 ⁷ cm ^-3) of submicrometer particles produced by the detonations of the explosives prepared from nanophase materials were comparable to that produced from the conventional formulation. Near real-time continuous data taken by a time-of-flight aerodynamic sizer and a scanning differential mobility analyzer indicate a multi-modal distribution that there were a peak between 700 and 900 nm, and one and/or two peaks smaller than 100 nm depending upon the explosive used in an individual experiment. The calculated growth rates of particles produced by the explosives in detonation were substantially higher, by two to three orders of magnitudes, than that typically seen in the atmosphere. The implication of the growth rate and its relationship to worker health and safety are discussed.