The Fire Station, The Station Articles, Tutterow

Apparatus Bays: Diesel Exhaust

Issue 2 and Volume 22.

By Robert Tutterow

This column is more about apparatus bays. As stated in my previous column, they are the common denominator of fire stations across the globe. How can you have a station without them? This column will focus on a huge health issue for firefighters: diesel exhaust.

National Fire Protection Association (NFPA) 1500, Standard on Fire Department Occupational Safety and Health Program, states: “The fire department shall prevent exposure to firefighters and contamination of living and sleeping areas to exhaust emissions.”

Diesel Exhaust

In addition to the International Agency for Research on Cancer (IARC), both the National Institute for Occupational Safety and Health and the Occupational Safety and Health Administration have declared human exposure to diesel exhaust a potential occupational carcinogenic (cancer-causing) hazard through toxicological studies. Much of the diesel exhaust is invisible, including the smaller soot particles. This means that exposure cannot always be detected. Furthermore, diesel exhaust can penetrate clothing, furniture, and other items with which firefighters have routine contact and later be absorbed into the skin.

Yet, many fire stations across the country have no method to reduce these carcinogens. Even though there are many variations in system configurations, practically any station can be retrofitted.

System Types

There are four systems on the market:

Source Capture Hose System: This hose system consists of an automatic disconnect nozzle that allows the vehicle to drive into and out of the station with the hose still attached. The hose disconnects from the vehicle and retracts into the bay as the vehicle leaves the station. There is an automatic activation with an inline pressure switch that automatically activates an exhaust fan to expel the captured exhaust to the exterior of the station. This system is only as effective as firefighters’ commitment to always connect the hose.

Source Capture Onboard System: The onboard system is mounted underneath the apparatus and integrated into the vehicle exhaust system. The system is about the size of a five-gallon bucket. It is an automatic and self-contained system that does not require a hose to be connected to the tailpipe. It automatically engages when the engine starts and when the apparatus is put in reverse. There is an override to activate the system while idling on the scene. The newer system for apparatus manufactured after 2007 activates immediately at cold start and low idle-both in the station and on scene. The system has a filter that has to be replaced. Busy metropolitan agencies report filter replacement is necessary approximately every 12 months. Some volunteer departments report the filter lasting close to 10 years.

Filtration Systems: For the best healthy air environment in the bay, one of the above described source capture systems as well as a filtration system should be used. The filtration system will capture off-gassing of other contaminated equipment brought into fire stations, such as fire hose, salvage covers, and PPE, that cannot be captured by a source capture. Current filtration systems recirculate heated air, and some offer photocatalytic oxidizers to help kill airborne bacteria and viruses. Filtration systems do not have hanging hoses, but their HEPA filters need replacing.

Mechanical Exhaust: This is the most inexpensive system, but it is not source capture and requires radiant heat to prevent heat loss unless you live in a very warm winter climate.

Two-System Rationale

Why am I suggesting two systems? It is simple. Cancer is an epidemic in the fire service. Every method available should be used to remove as much of the carcinogens as possible. Source capture works well with diesel exhaust, assuming the systems are used-especially with a hose connect system. And, the filtration systems work well for items that off-gas in a station.

I recently had a chance to visit a station that is less than five years old. The company is a very busy company, and it has a source capture system. Yet, there was an alarming amount of soot on the surfaces of the items located on the apparatus floor. It confirmed my belief that there is a need for both systems.

These systems can be retrofitted into existing stations-they are not just something to consider with a new station. Finally, these are in addition to any codes that might require that apparatus bays be ventilated with fresh air.

ROBERT TUTTEROW retired as safety coordinator for the Charlotte (NC) Fire Department and is a member of the Fire Apparatus & Emergency Equipment editorial advisory board. His 34-year career includes 10 as a volunteer. He has been very active in the National Fire Protection Association through service on the Fire Service Section Executive Board and technical committees involved with safety, apparatus, and personal protective equipment. He is a founding member and president of the Fire Industry Education Resource Organization (F.I.E.R.O.).