NIOSH Evaluation of Aircraft Hangars Identifies Sampling Strategy, Ventilation Improvements

Published June 1, 2016

​Environmental health and safety managers at a military facility recently requested NIOSH’s assistance to characterize airflow inside four aircraft hangars used to maintain, repair, and restore active and historic aircraft. Workers in the hangars apply paints and paint removers on a variety of surfaces using low-pressure spray guns or paint rollers. Others remove old aircraft surface coatings using tools such as mechanical or pneumatically-driven sanding equipment, grinders, or scrapers; according to NIOSH, the particulate generated during this removal may contain isocyanates, polyurethanes, solvents, or metals. The health and safety staff assigned to the hangars intended to use the information from NIOSH’s evaluation to help them select where to conduct sampling for potential air contaminants so that they could evaluate exposures under worst-case ventilation conditions. The information would also be useful to identify areas where exposure controls could be necessary.

Over the course of two visits, NIOSH personnel evaluated all four hangars; they checked airflow patterns using a smoke machine and measured both air speed and direction and pressure differences between the hangars and surrounding areas. Agency staff identified areas of little to no airflow in the two maintenance hangars in work zones above the wings and fuselage and on the side of the aircraft closest to the exhaust fans. Air movement magnitude and patterns were variable in the restoration hangars, partially due to portable cooling fans used to provide increased comfort to workers on warm days. However, NIOSH found areas of low airflow in the restoration hangars as well, especially near the back of the structures.

Based on the agency’s findings, NIOSH recommends that health and safety staff focus personal and area air sampling efforts in the areas of low airflow in the work zones nearest the exhaust fans in the maintenance hangars, and during tasks that that may generate air contaminants that occur away from the portable cooling fans in the restoration hangars. The agency’s report also urges the employer to repair, adjust, and maintain all fans associated with the ventilation system in the maintenance hangars, and to repair the exhaust fans in the windows of the restoration hangars.

View the full report on NIOSH’s website (PDF).