OHST Practice Exam

Which operation typically releases the largest amount of airborne contaminants that require high capture velocities in ventilation design?

1. Welding

2. Evaporation from tanks

3. Spray painting

4. Grinding

The correct answer is: Grinding

Grinding operations typically release the largest amount of airborne contaminants due to the nature of the process. During grinding, particulate matter is generated as the material is mechanically removed from a surface. This creates a significant amount of fine dust and debris that can easily become airborne. Consequently, to effectively control these particles and protect worker health, ventilation systems must be designed with high capture velocities. This ensures that the airborne contaminants are quickly and efficiently drawn into the ventilation system before they can disperse into the work environment. In contrast, while welding, evaporation from tanks, and spray painting also produce airborne contaminants, the scale and type of particles generated during grinding operations generally require more robust ventilation measures. For instance, spray painting releases volatile organic compounds (VOCs) which may require specialized ventilation strategies focusing on overall air quality rather than simply capturing particulates. Similarly, welding fumes are primarily composed of metal vapors, which can often be effectively controlled with different ventilation techniques. The evaporation process from tanks may produce lighter vapors that do not require the same high flow velocities. Thus, grinding stands out in this context as the operation that necessitates higher capture velocities due to the volume and nature of the contaminants involved.