Hazard evaluation and technical assistance report: HETA-99-0313-2802, The Children's Hospital of Denver, Denver, Colorado.
On August 11, 1999, the National Institute for Occupational Safety and Health (NIOSH) received a request for a health hazard evaluation (HHE) from the management of The Children's Hospital of Denver (TCH), to evaluate employees' potential health hazards encountered during inhaled nitric oxide (INO) therapy. NIOSH investigators conducted two site visits to meet with management and observe the use of INO during therapy. During a third visit, personal breathing zone (PBZ) samples and general area (GA) samples were collected for nitric oxide (NO), nitrogen dioxide (NO2), and nitric acid (HNO3). The ventilation system was assessed in the two closets where the NO cylinders are stored, and in the treatment area. All of the PBZ and GA samples collected for NO, NO2, and HNO3 were well below the relevant evaluation criteria for occupational exposures. The respiratory care storage closet and the pediatric intensive care unit (PICU) had adequate ventilation in controlling the low concentrations of NO produced from INO therapy. The PICU had 8-10 air exchanges per hour. A need for ventilation was identified in the NO compressed gas storage closet, which had only a duct leading to the outside of the building. The industrial hygiene sampling data indicate that employees were not overexposed to NO, NO2, or HNO3 at The Children's Hospital of Denver during inhaled nitric oxide therapy. Ventilation was adequate in the pediatric intensive care unit and the respiratory care closet. Recommendations for improved ventilation in the compressed gas storage closet are given in the recommendations section of this report.