Testing Results of Streaming Agent Replacements for Halon 1211
Mainstream researchers tested a novel tropodegradable
fluorinated agent and blends of this agent with with 1-bromopropane
for streaming fire suppression applications. We
performed large-scale fire suppression tests and determined the toxicity
characteristics of the agents, the cardiac sensitization
NOAEL of the candidate agents and the atmospheric impact
of the agents. We also performed materials compatibility experiments, determined
the agent decomposition products, characterized the physical properties
of the agents, and assessed the manufacturability of the agents.
This novel agent has the potential to be a substitute for Halon
1211 and HFC-236fa for streaming fire suppression applications.
Although to extinguish a fire it requires more agent, higher agent discharge rates, and higher
discharge times than Halon 1211, our agent
has the same fire suppression performance as HFC-236fa. Also, the
fire suppression tests showed that the addition of 1-bromopropane
to either octafluoro-2-butene or HFC-236fa had marginal, if any,
performance benefits.
Contrary to Halon 1211, which is a known ozone depleter with high GWP, our agent does not have the negative atmospheric impact of
either Halon 1211 or HFC-236fa because it has a zero ODP, low atmospheric
lifetime and low GWP. Although HFC-236fa has zero ODP, it has a high atmospheric
lifetime and high GWP.
The toxicity information developed on this project indicate that
more subchronic and long-term toxicity information is required.
It does not appear to be as potent of a cardiac sensitizer as other
fire suppression agents or refrigerants, but it did appear to cause
lethality in dogs after exposure to 9% agent in air. The cause for
these lethalities also needs to be evaluated.
Materials compatibility tests indicated that the agent was compatible
with all the metals we evaluated, and had less of an affect on the elastomers
we evaluated than Halon 1211 did. Agent decomposition analysis showed
it generated low levels of acid gases (HF), but no other toxic decomposition
products were detected.
For this novel agent to be a commercial fire suppression agent,
more work on manufacturability needs to be performed. Specifically,
the cost of the agent needs to be significantly reduced to the
range of $20-$40/lb. Initial estimates of the cost of manufacturing
in large quantities in a continuous process show that this cost
reduction is feasible with some process development work and the
building of a suitable plant.
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