unique227 Chemical & Physical Properties

1.1        Chemical & Physical Properties

Table 1-2: Chemical and Physical Properties of UNIQUE 227®

1.6 Environmental Properties
The environmental properties of HFC-227ea and other fire extinguishing agents are given in Table 1-
3. All data were compiled from published sources.

Table 1-3: Environmental Properties of Fire Extinguishing Agents

¹ World Meteorological Organization (WMO) 1998, Model-Derived Method

² Intergovernmental Panel on Climate Change (IPCC) 2007 Method, 100-Year ITH

1.7 Thermal Decomposition
The thermal decomposition product (TDP) of primary concern for HFC-227ea is hydrogen fluoride (HF) (ACGIH TLV = 3 ppm). HF is a highly dangerous gas, since it forms a highly corrosive and penetrating hydrofluoric acid upon contact with tissue. Other thermal decomposition products include carbon monoxide and carbon dioxide. Prior to re-entry of a room where the HFC-227ea system has been activated to suppress a fire, air tests must be performed.

There is a direct correlation between the agent discharge time and the amount of TDP created. As a result, the type of fire and the amount of agent exposed to open flame are critical. However, the formation of thermal decomposition products will be minimized by the use of Unique FIre early warning detection systems.

Following is a list of safety provisions to prevent personnel from injury when working close to or in the environment protected by Clean Agent systems.
1) Emergency lighting and directional exit signs.
2) Clear aisles and passages for exit routes.
3) Self-closing exit doors that have panic hardware provisions.
4) Continuous alarms during the HFC-227ea discharge and afterward until normal atmosphere have been restored in the area.
5) Alarms within and outside of the area that will operate upon first detection of fire.
6) Warning signs located at the entrances to, and inside the areas, to inform that the HFC- 227ea system is installed with instructions that are needed for the particular hazard.

The discharge time of HFC-227ea at 70°F has been established at 10 seconds maximum regardless of the amount discharged. The reasons for the rapid discharge are:
1) Limit the amount of thermal decomposition products generated;
2) Limit fire damage and its effects; and
3) Enhance the mixing.

Note: See Appendix of NFPA–2001, Battery march Park, Quincy, Massachusetts 02169, for further discussion of HFC-227ea Fire Fighting mechanism.

1.8 Materials Compatibility
UNIQUE 227® systems shall not be used on fires involving the following materials:

1) Certain chemicals or mixtures of chemicals, such as cellulose nitrate and gunpowder, which are capable of rapid oxidation in the absence of air;
2) Reactive metals, such as lithium, sodium, potassium, magnesium, titanium, zirconium, uranium, and plutonium;
3) Metal hydrides; and
4) Chemicals, that is capable of undergoing auto thermal decomposition, such as certain organic peroxides and hydrazine.

1.9 Safety Considerations
The HFC-227ea has been evaluated for cardiac sensitization through test protocols approved by the United States Environmental Protection Agency (EPA). The HFC-227ea has acceptable toxicity and cardiac sensitization levels for use in occupied spaces as specified in the United States EPA Significant New Alternative Policy (SNAP) program rules.

Based on NFPA 2001, the No Observable Adverse Effect Level (NOAEL) for HFC-227ea is 9% and its Lowest Observed Adverse Effect Level (LOAEL) is 10.5%. The NOAEL is the highest concentration that no adverse physiological or toxicological effect has been observed while the LOAEL is the lowest concentration, which an adverse physiological or toxicological effect has been observed.

Consideration shall be given to the possibility of agent migrating to adjacent areas outside the protected space. Care must be taken to insure that the calculated concentration for normally occupied spaces does not exceed the NOAEL.

WARNING: HFC-227ea is discharged through the nozzle orifices. Direct eye or skin contact with the liquid or cold gas can cause chilling or possibly frostbite on exposed tissues. Misuse or intentional inhalation abuse can cause suffocation or death. Do not stand directly in front of the discharge lines as the discharge pressure could cause injury. The nozzles are used to discharge the HFC- 227ea in a horizontal direction. The flow of HFC-227ea should not be blocked by any obstructions. Please read and follow the precautions and the safety related information in the Material Safety Data Sheet (MSDS).