Do Not Use ABC or Dry Chemical Extinguishers with "Wet Chemical" Systems
Due to incompatibilities between ABC/BC Dry Chemicals, "Wet Chemical" systems require the installation of a K-Class extinguisher. This extinguisher utilizes the same agent as the hood system. Firefighters should avoid using a dry chemical extinguisher on a wet chemical application. The mixing of these agents will hamper the systems ability to adequately extinguish a fire occurring under a cooking hood.
The hazard created by this system is not the chemical but the method by which it is discharged. These extinguishing systems use pressurized gases to expel the chemical from tanks through the pipes and nozzles.
If the system has discharged prior to fire department arrival this is not an area of concern. However, if the system has not discharged firefighters could suffer injuries from the discharge of these systems during firefighting, salvage and overhaul operations. The same danger applies to fire investigators involved in investigation activities.
The status of systems must be checked prior to personnel being allowed in areas with these systems. Safety officers should be familiar with the operation of these systems. Any systems found to be operational should be identified and disengaged. Personnel involved in firefighting operations should be aware of the hazards and suppression operations should be conducted in a safe manner.
Responses to incidents of these types require the fire department to notify the county health department. The health department requires the restaurant to be shut down and a health inspection conducted. All violations and issues must be corrected and approved by the health department prior to a restaurant being allowed to reopen.
Understanding the hazards and preplanning is the key to handling a situation involving these types of incidents. Fire departments must be aware of the locations that utilize these systems and fire department personnel educated in the use of these systems. Once the training aspect has been handled, operating guidelines and procedures must be implemented to safely and effectively mitigate these hazards.
Mark A. Brown has been involved in the fire service for 19 years and currently serves as Fire Prevention Bureau Chief for the Concord Department of Fire & Life Safety located in Concord, North Carolina.
Since becoming a firefighter in 1987, he has been promoted through the ranks of the fire department and has served numerous positions including fire training officer and fire marshal. Mark has assisted the North Carolina Office of the State Fire Marshal in the development of the Hazardous Materials Technician Certification Program and currently assists in the instruction and delivery of the program.
Mark possesses numerous certifications in several different fire department disciplines including Firefighter Level II, Fire Inspector Level III, Fire Instructor Level III, Hazardous Materials Technician/Transportation Specialist and WMD Technician. He possesses an Associates Degree in Fire Protection and is also a recently appointed board member of the North Carolina Fire Marshal's Association.