What is a significant risk when using downdraft hoods?

When considering the use of downdraft hoods, one of the significant risks is the potential for exposure to workers' heads. Downdraft hoods are designed to capture contaminants by pulling fumes or particles downward toward the hood, which can effectively remove harmful substances from the breathing zone. However, the design of these hoods can inadvertently create a situation where the airflow and downdraft may expose workers to contaminants that are near the height of their heads. If a downdraft hood is not functioning correctly or is improperly positioned, it may not provide adequate protection for individuals standing nearby, increasing the risk of inhalation of hazardous substances.

In contrast, while the other options may raise concerns regarding downdraft hoods – such as the adequacy of contaminant capture or odors – they do not specifically highlight the direct physical exposure risk to workers' heads. The design and operational functionality of the downdraft system are critical in minimizing exposure levels, and understanding this risk is essential for maintaining safety in environments where these hoods are utilized.