Air filters, portable air cleaners and related consumer products undergo testing with challenge dusts to establish product performance and impacts on indoor air quality. Testing generally relies on synthetic dusts produced from mineral components that are designed to replicate real household dust. It is challenging to produce a standardised dust that’s fully representative of household dust due to the range of materials present in household dust (including skin cells, hair, fibres, soil particles, bacteria, dust mites, pollen, other allergens, and a variety of chemicals).
This study aimed to investigate the aerodynamic properties of two standardised dusts, and to compare their performance to that of real household dust. Samples of synthetic dust produced from mineral components, a mixed synthetic house dust (with mineral and fibre components) and real house dust were investigated. The dust samples were aerosolised in an environmental chamber, where their natural decay was monitored at three different heights using aerodynamic and optical particle counters.
Data were analysed to characterise airborne particle counts, particle size distributions and rate of decay for each type of dust. The standardised dusts were found to be more readily aerosolised compared to the household dust. Analysis of particle decay rates showed that the mineral dust settled out of the air more rapidly than the other dusts, and the natural decay of the mixed synthetic dust more closely replicated that of the house dust. These findings may inform the design and production of optimised test dusts for use in establishing consumer product performance.