Two recent NIOSH Health Hazard Reports (HHEs) underscore the need for firefighters to use diesel exhaust extraction systems—even when firefighters are conducting routine running of the apparatus during equipment checks.
The hazards of diesel exhaust prompted the stations’ chiefs to request the two HHE studies.
In a 2017 study (HHE Report No. 2016-0094-3267), two fire stations were evaluated. The diesel fire engines in the stations were built in 1992 and 1999. As the study noted: “more than 95 percent of diesel exhaust particulate is less than 1 micrometer in size and is respirable. Because of their small size, diesel exhaust particles can be inhaled deeply into the lungs and even into the bloodstream.”
The NIOSH researchers monitored particulate concentrations throughout the day and also used ventilation smoke tubes to observe and monitor airflow direction.
The tests revealed that just after the diesel-engine-powered equipment was started in the bay, exhaust appeared to be flowing into the living quarters. The researchers also noted that an existing tailpipe exhaust system at one of the stations was not being used for equipment checks. “The firefighters indicated that this hose was used for maintenance that had to be done inside the bay, but it was not used during equipment checks in the bay.”
Among the recommendations made by the NIOSH researchers were to “install diesel control systems to decrease the amount of diesel exhaust in the apparatus bay” and to “use the tailpipe exhaust hose at station 1 when conducting equipment checks in the bay.”
Local Exhaust Extraction Needed, Even with Modern Diesel Engine Technology
The other NIOSH study was done in 2016 (HHE Report No. 2015-0159-3265), and also recommended a local exhaust ventilation system for a station, despite the station carrying modern engines that employed ultra-low sulfur diesel fuel and contained diesel particulate filter and regeneration systems.
As the report noted, “Although exposures were low in all the stations, efforts to further reduce exposures are appropriate because of the potential health risks from exposures to diesel exhaust.”
The study also recommended the consideration of “local exhaust ventilation systems that attach directly to apparatus diesel exhaust in the back-in only station.”
The Challenge: Making Diesel Exhaust Extraction Systems Easier to Use
The diesel exhaust extraction industry has been focused on adding features to make their systems easier to use. For example, Plymovent has installed more than 50,000 source capture systems in North America, and in the past few years has added features that enable firefighters to conduct routine equipment checks inside the station.
For example, firefighters can operate their system in a “manual” mode during extended running and equipment checks, and when the check is complete, the STOP button is pressed and the manual system switches back to “automatic” mode so the system is ready for the next emergency run, in which the exhaust hose automatically disconnects from the tailpipe as the truck exits the station.
For more information, visit: http://www.plymovent.com/us/vehicle-exhaust-extraction/segments/fire-and-emergency-service-stations.
Read the full HHE reports at https://www2a.cdc.gov/hhe/search.asp.