What potential issue is associated with soluble powders (SP)?

Soluble powders (SP) are formulations that dissolve in water to form a solution. One of the primary concerns associated with the handling of soluble powders is the potential for dust inhalation while mixing and loading the product. When these powders are measured and poured, they can easily become airborne, creating a dust that may be inhaled by the person handling the material. This inhalation can pose health risks, particularly due to the chemicals present in some pesticides.

The other options do have some relevance in the context of soluble powders, but they do not address the health and safety risk as directly as the issue of dust inhalation. For example, while soluble powders are indeed nonabrasive on equipment, do not leave visible residues, and may require agitation to dissolve properly, these factors are not as critical in assessing the safety concerns linked to their use. The key takeaway is that the risk of inhaling dust during the mixing and loading process makes proper personal protective equipment and handling procedures essential when working with soluble powders.