NIOSH: Helicopter Exhaust Likely Predominant Source of Odors in Office Building

Published November 15, 2017

​Helicopter exhaust from a nearby helipad was likely the predominant source of transient odors in a large commercial office building in which employees expressed concerns about potential exposure to fuel and other chemical odors, according to a new report from the NIOSH Health Hazard Evaluation Program. Other possible sources of fuel odors included nearby diesel emergency generators, two large ferry terminals, and a large highway, according to the NIOSH staff who evaluated the workplace to address indoor environmental quality and health concerns. The agency’s report notes that more than 300 odor incidents in which employees reported respiratory tract irritation, burning eyes and skin, headaches, and increased asthma symptoms had been documented in the building since 2012. Over two days, NIOSH staff assessed the sources of transient fuel and other chemical odors entering the building, the effectiveness of the building’s ventilation system, and whether the symptoms employees experienced were consistent with exposures to fuel and other chemical odors.

Transient odors from nearby external sources, including the helipad, were likely entering the building’s outdoor intakes and resulting in the periodic fuel odor complaints, NIOSH’s report says. The odors could have been contributing to the workers’ reported symptoms. Agency staff found that the building’s use of activated charcoal filters was ineffective in capturing and removing odors from outdoor air.

“Ventilation controls, such as filtration, are unlikely to eliminate the problem,” the report concludes. “Strategies to reduce the fuel odors include removing or reducing the sources of the external exhaust.”

NIOSH urges the employer to work with municipal authorities to find ways to help reduce or eliminate the external exhaust sources from helicopters. Possible approaches include altering flight paths so that exhaust is not blowing toward the building or reducing the number of idling helicopters on the helipad. The agency also recommends a test and balance of the building’s ventilation system to verify whether sufficient outdoor air is being supplied. Other actions the employer can take include implementing an IEQ management program and relocating employees who are sensitive to the fuel odors to a different area of the building.

Further details and recommendations are available in NIOSH’s report (PDF).