At a technical session during the National Safety Council''s (NSC) Congress yesterday in Orlando, Fla., Bayard Pelsor, MS, EHS manager of The Shepard Chemical Co., Cincinnati, Ohio, told attendees how to prevent indoor air pollution.
Pelsor presented the results of a study of an indoor air quality problem he investigated at a laboratory facility.
He identified that the laboratory hood exhaust was contaminating a fresh air supply. The suspected cause was the existing exhaust design and proximity to air intakes.
Pelsor explored solutions to solve the problem, including modifying exhaust stacks by removing the rain cap and attaching a cone-shaped nozzle to increase air velocity and eliminate downward deflection of exhaust.
He then tested and refined the solution by conducting inside air monitoring and observing outside contaminants.
In his assessment of the outcome, Pelsor said the new stack design resulted in adequate vertical dispersion of the exhaust to prevent contamination of air supply.
Pelsor offered the following recommendations to prevent indoor air pollution:
- Inspect the facility for potential exhaust re-entrainment.
- Consider potential for containment and environmental conditions.
- As a safety professional, get involved in the early stages of designing ventilation systems at facility.
- Monitor workplace areas.
- Look at the design location and origin of exhaust stacks relative to supply air intakes.
by Virginia Sutcliffe