Final Report: System To Deliver Halon Equivalent, Hydrogen Fluoride Controlled, Supplemented HFC Gases in Fire Sensitive, Light Weight, Plastic Extinguishers

EPA Contract Number: 68D00259
Title: System To Deliver Halon Equivalent, Hydrogen Fluoride Controlled, Supplemented HFC Gases in Fire Sensitive, Light Weight, Plastic Extinguishers
Investigators: MacElwee, Donald B.
Small Business: Powsus Inc.
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $69,482
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text |  Recipients Lists
Research Category: SBIR - Pollution Prevention , Pollution Prevention/Sustainable Development , Small Business Innovation Research (SBIR)


This purpose of this project was to demonstrate proof-of-concept that a fire-sensitive plastic tube containing an EPA SNAP approved extinguishant could effectively and automatically put out fires in engine compartments and other confined high fire risk areas. A schoolbus engine was chosen as a typical application that relates also to marine engines, train, truck, car, and air cargo compartments, all of which have little or no automatic fire protection today. The project consisted of defining, analyzing, and then testing Nylon tubing for use in elevated ambient temperatures of a confined engine compartment fire source.

Three Nylon resins with varying structural characteristics, modified to reduce permeability of gas extinguishant, were chosen for evaluation based on recommendations from resin manufacturers. A SNAP-listed HFC gas was sealed in samples of the chosen tubing and stored at ambient and elevated temperatures to measure permeability and possible leakage potential. Hydrostatic testing was used to compare tubing structural integrity. Over-the- road tests were used to measure the airflow and temperature profiles in a schoolbus engine compartment to determine potential tubing environments. Based on these tests, several formulations of Nylon were determined to be suitable for the potentially higher temperature exposure in a bus engine compartment. Engine compartment data was used to design and construct an engine compartment simulator (including variable airflows) which permitted repeated testing under a wide range of fire test scenarios.

The most likely and most uniform fire source for testing is a fuel spray such as could occur from a cracked fuel line. The fire source chosen was heptane due to its wide acceptance in the fire extinguishing industry and increased safety of handling. Testing in the simulator showed that with the engine generating any air flow, only minimal fires could be generated. It was only with engine off conditions that conflagration would take place. Once the fire scenario was established, extinguishing agent was applied to determine required agent amounts. At this point Envirogel tubes could be fabricated for actual testing and evaluation in the simulator.

During this project, a preliminary market survey conducted by Foresight Science & Technology, Inc. indicated that there is a large worldwide market for this product in marine engines. Powsus has contacted two of the three major distributors of marine fire protection equipment (Kidde and Metalcraft) who have asked to participate in follow on work for commercialization of this product. Federal Express has ordered additional research for use of this product to protect cargo containers and pallets, and the Department of Transportation is helping initiate research for use of this product in public transportation systems, specifically SEPTA, (South East Pennsylvania Transportation Authority) for subway trains, trains and busses. Foresight S&T Inc. discouraged early stage marketing of the product to the Schoolbus markets due to the highly disparate and diverse locations of the decision-makers in this field.

Summary/Accomplishments (Outputs/Outcomes):

Three Nylons were evaluated for use in fire protection of specific confined areas. Nylon 11 is excellent for use in areas of normal ambient temperatures such as air cargo containers and hazardous material containers. Nylon 6 and Nylon 6-6 appreared suitable for areas of higher ambient temperatures such as confined engine compartments. The amount of agent, Envirogel, required is dependent upon volume of the container and whether conditions permit full flooding or partial flooding of the container. In totally enclosed containers such as boat engines or cargo compartments, less agent is needed because suppression concentrations can be maintained for longer periods. Open engine compartments, such as a bus engine, range from ten percent to seventy five percent open, and more extinguishing agent (overkill) will be required because extinguishing concentrations cannot be maintained.


The use of plastic tubing and SNAP-listed Envirogel can be an inexpensive and efficient solution for automatic fire protection of vehicles, boats, cargo compartments, and confined areas. Pre-engineered systems can be established for highly enclosed volumes, and more open configurations can be engineered.

Repeated successful fire suppression testing during this program indicates that this technology should be moved toward commercialization in conjunction with recognized regulatory and testing agencies such as UL, FM and Coast Guard.

Supplemental Keywords:

small business, SBIR, fire suppressant, halon alternative, global climate, pollution prevention, engineering, chemistry, EPA., RFA, Scientific Discipline, Air, Toxics, Sustainable Industry/Business, Chemical Engineering, air toxics, climate change, CFCs, New/Innovative technologies, tropospheric ozone, Atmospheric Sciences, EPCRA, Engineering, Chemistry, & Physics, Environmental Engineering, environmental monitoring, HFC, hydroflurocarbon(HFC), halon, Hydrogen fluoride, ozone, ozone depletion, global change, halon equivalents, fire suppression, fire extinguisher, halons, global warming

SBIR Phase II:

System to Deliver Halon Equivalent, Hydrogen Fluoride Controlled, Supplemented HFC Gases in Fire Sensitive, Light Weight, Plastic Extinguishers  | 2000 Progress Report  | Final Report