Which environmental condition increases spray drift risk indoors?

• A. Good ventilation and steady air currents.
• B. Outdoor wind dispersal.
• C. Poor ventilation, air currents, and fan or HVAC airflow can spread irritant; closed spaces increase exposure risk.
• D. Closed spaces with no air movement reduce risk.

Answer: (C)

Inside environments, spray drift happens when air moves the irritant, carrying fine droplets away from the target. Any air movement—whether from poor ventilation, general air currents, or a fan or HVAC system—can push the spray to unintended areas and people. When ventilation is poor, the irritant isn’t diluted or exhausted quickly, so it lingers and can spread further through those same air currents. Closed spaces worsen exposure risk because the spray isn’t being removed from the room efficiently, allowing it to stay airborne and reach bystanders.

Outdoors, wind dispersal operates differently and isn’t the same indoor risk. Good ventilation and steady air currents typically help remove or dilute spray, reducing drift rather than increasing it. A space with no air movement indeed reduces how far the spray travels, but that situation doesn’t increase drift risk.