Document ID: EPA-HQ-OAR-2011-0111-0018
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2012-09-19T04:00Z

Significant New Alternatives Policy Program
Fire Extinguishing and Explosion Prevention Sector
Risk Screen on Substitute for Halon 1211 as a Streaming Agent in Portable Fire Extinguishers
               Substitute: C7 Fluoroketone (C7 FK or FK-6-1-14)
This risk screen does not contain Clean Air Act (CAA) Confidential Business Information (CBI) and, therefore, may be disclosed to the public.
1.	INTRODUCTION
Ozone-depleting substances (ODS) are being phased out of production in response to a series of diplomatic and legislative efforts that have taken place over the past two decades, including the Montreal Protocol and the Clean Air Act Amendments of 1990 (CAAA).  The U.S. Environmental Protection Agency (EPA), as authorized by Section 612 of the CAAA, administers the Significant New Alternatives Policy (SNAP) Program, which identifies acceptable and unacceptable substitutes for ODS in specific end-uses based on assessment of their health and environmental impacts.  

EPA's decision on the acceptability of a substitute is based largely on the findings of a screening assessment of potential human health and environmental risks posed by the substitute in specific applications.  EPA has already screened a large number of substitutes in many end-use applications within all of the major ODS-using sectors, including: refrigeration and air conditioning, solvent cleaning, foam blowing, aerosols, fire suppression, adhesives, coatings and inks, and sterilization. The results of these risk screens are presented in a series of Background Documents that are available in EPA's docket.

The purpose of this risk screen is to supplement EPA's Background Document on the fire and explosion suppression sector (EPA 1994) (hereinafter referred to as the Background Document). This risk screen evaluates the potential use of C7 Fluoroketone (also referred to as FK-6-1-14 or C7 FK) as a substitute for Halon 1211 to be used as a streaming agent in portable fire extinguishers. The proposed substitute is anticipated to be used for Classes A (ordinary combustibles), B (flammable liquids and gases), and C (electrical) fires, pending UL approval. The reader is referred to the Background Document for the methodologies and assumptions used to conduct the risk screen. Table 1 presents the composition of the proposed substitute. 
                         Table 1. Composition of C7 FK
                                  Constituent
                               Chemical Formula
                                  CAS Number
                               Percent of Total
                                (by weight)[a]
        3-Pentanone,1,1,1,2,4,5,5,5-octafluoro-2,4-bis(trifluoromethyl)
                                    C7F14O
                                   813-44-5
                                    55-65%
       3-Hexanone,1,1,1,2,4,4,5,5,6,6,6-undecafluoro-2-(trifluoromethyl)
                                    C7F14O
                                   813-45-6
                                    35-45%

The potential risks associated with use of substitutes in streaming agents for portable fire extinguishers have been examined at length in the Background Document.  The reader is referred to this reference for a detailed discussion of the methodologies used to conduct this risk screen.  Occupational exposure modeling was performed to ensure that use of the proposed substitute did not pose unacceptable risk to workers during equipment manufacture.  Modeling was performed at the end-use to ensure that potential releases of the proposed substitute did not pose unacceptable risk to fire fighters and other end-users in locations where the fire extinguishers are in use.  Lastly, general population exposure modeling was performed to ensure that the proposed substitute would not pose unacceptable risk to the population at large.  

Section 2 of this report summarizes the results of the risk screen for the proposed substitute.  The remainder of the risk screen is organized into the following sections:

         * Section 3: Atmospheric Assessment
         * Section 4: Potential Health Effects
         * Section 5: Occupational Exposure Assessment
         * Section 6: End-Use Exposure Assessment
         * Section 7: General Population Exposure Assessment
         * Section 8: Volatile Organic Compound Assessment
         * Section 9: References
2. 	SUMMARY OF RESULTS
Use of C7 FK in portable fire extinguishers is not expected to pose a significant risk to atmospheric integrity or to the health of the general population, and is therefore recommended for SNAP approval for the proposed end use.  Given that proper training will be given to personnel and that appropriate personal protective equipment (PPE) (Occupational Safety & Health Administration [OSHA] Category D or higher) and proper procedures according to the MSDS (including provisions of adequate ventilation) will be used during manufacturing, end-use, and disposal, no risk to workers, end-users, or the general population is anticipated. In addition, this risk screen indicates that the use of the proposed substitute will be less harmful to the atmosphere than the continued use of Halon 1211, HCFC-123, or HFC-236fa. For applications of this and all other fire suppression equipment, ICF recommends that use be in accordance with the latest edition of the National Fire Protection Association (NFPA) 10 Standard for Portable Fire Extinguishers.  
3. 	ATMOSPHERIC ASSESSMENT
This section presents an assessment of the potential risks to atmospheric integrity posed by the use of C7 FK as a streaming agent.  The ODP, GWP, and ALT of the proposed substitute and replacements are presented in Table 2. The proposed substitute is substantially less harmful to the ozone layer and has less climate impact than Halon 1211. In addition, its low GWP relative to HCFCs and HFCs will provide environmental benefit compared to other available options in streaming applications.  
 Table 2.  Atmospheric Impacts of C7 FK Compared to Halon 1211 and Other Intended Non-ODS Replacements
                                Streaming Agent
                                      ODP
                                      GWP
                                  ALT (years)
                                     C7 FK
                                     0[a]
                                     1[a]
                                   7 days[a]
                                  Halon 1211
                                    7.1[b]
                                   1,890[b]
                                     16[b]
                                   HFC-236fa
                                       0
                                   9,650[c]
                                    240[c]
                                   HCFC-123
                                    0.02[b]
                                     77[b]
                                    1.3[b]
   a  3M SNAP Submission 2010  
   [b] Available at: http://www.epa.gov/ozone/ods.html.
   [c] Available at: http://www.epa.gov/ozone/geninfo/gwps.html 	 		
4. 	POTENTIAL HEALTH EFFECTS
According to the MSDS, exposure to C7 FK above the exposure guideline may result in potentially harmful health effects. Inhalation of C7 FK could cause respiratory tract irritation and symptoms may include cough, sneezing, nasal discharge, headache, hoarseness, and nose and throat pain. If thermal decomposition of the compound occurs, inhalation of the decomposition products may also be harmful. If over exposure due to inhalation of C7 FK above the exposure guideline occurs, person(s) should be immediately removed and exposed to fresh air and medical attention should be sought if the above mentioned symptoms develop. Contact with the eyes and/or skin during product use is not expected to result in significant irritation. Ingestion of C7 FK is not expected to cause health effects, and there is no anticipated need for first aid if ingestion of C7 FK occurs (3M 2011b). EPA's review of the environmental and human health impacts of this proposed substitute is contained in the public docket for this decision.
 When good industrial hygiene practices and the PPE and engineering control (e.g., ventilation) recommendations outlined in the MSDS for C7 FK, as summarized in Sections 5 and 6 of this risk screen, are followed, these potential health effects are unlikely to occur.
 5.	OCCUPATIONAL EXPOSURE ASSESSMENT
C7 FK is manufactured in a closed system. According to the submitter, workers may be exposed to C7 FK during the manufacture of the product during direct line filling of drums/containers, as well as during installation of the fire extinguishing systems (e.g., accidental discharge). The potential for personnel exposure during manufacture and installation and maintenance are examined in this section. ICF's estimated acceptable exposure limit (AEL) for C7 FK is 225 ppm (3368 mg/m[3]) averaged over an 8-hour time period (8-hour TWA) (ICF 2011). The AEL was derived using an interspecies uncertainty factor of 3 and an uncertainty factor of 3 to compensate for uncertainty in the database  -  i.e., use of a 28-day, rather than a 90-day subchronic or 2-year chronic study to develop the 8-hour AEL. The reader is referred to Appendix A for a detailed explanation of the development of the AEL.  The substitute's manufacturer also recommends an AEL of 225 ppm (8-hr TWA) for C7 FK.	
5.1	Occupational Exposure during Manufacture

For small to moderate spills of C7 FK (< 100 kg), it is recommended that the area in which the spill occurs be cleared of personnel until ambient concentrations return to acceptable levels. The submitter modeled two scenarios to determine the appropriate reentry time in case of a spill. In both scenarios, the ventilation rate was fixed at 6 air changes per hour (ACH) and 4.5 kg of C7 FK was released to simulate a small leak (see Table 3) (3M 2011a).

                        Table 3. C7 FK Spill Monitoring
                             Scenario Room Volume
                              Peak Concentration
                                 Reentry Time
                                   100 m[3]
                                   2,200 ppm
                                    28 min
                                   1000 m[3]
                                    225 ppm
                                   Immediate

It is recommended that each manufacturing facility has the appropriate staff and resources to design the appropriate working environment and adhere to reentry time guidance following a leak of the substance. The submitter concludes that factory production of the C7 FK using the same procedures as for C6 FK would result in short term worker exposure of less than 1 ppm for C7 FK. In addition, personal protective equipment (PPE), as suggested in the MSDS, is recommended for workers dealing with C7 FK in industrial settings where ventilation is inadequate to control exposure below the recommended exposure guideline.  For manufacture of fire extinguisher systems, the amount of proposed substitute released during leak testing has been estimated to be less than 30 grams per year (3M 2011a).
5.2	Occupational Exposure during Installation and Maintenance
To address the potential employee exposure to C7 FK for larger amounts of the proposed substitute, the submitter provided surrogate air monitoring studies for a C6 fluorinated ketone (C6 FK or Novec(TM) 1230) analog. Air concentrations found during the air monitoring studies with C6 FK (described below) would be a conservative estimate of air concentrations of C7 FK, due to the higher boiling point and lower vapor pressure of C7 FK (see Table 4) (3M Novec(TM) 1230 SNAP Submission, 2001). 

     Table 4. Boiling Point and Vapor Pressure for C7 FK and C6 FK Analog
Parameter
                           C7 FK Proposed Substitute
                                 C6 FK Analog
Boiling Point
                                     74 C
                                     49 C
Vapor Pressure
                              125 mmHg (at 20 C)
                              244 mmHg (at 20 C)

According to the submitter, monitoring was conducted in two scenarios to determine the concentration of C6 FK during packaging, servicing, and disposal operations, which are reflective of manufacturing conditions for either draining the reactor or draining to drums post purification as part of the filling process for fire extinguishing units. The first scenario was tote filling, and monitoring was conducted without local exhaust which resulted in an area TWA concentration of 60 ppm. The peak instantaneous concentration for this scenario was 300 ppm, which is above the recommended AEL of 225 ppm over an 8 hour period; however, this scenario was modeled without the use of local exhaust. The second scenario, drum filling, was performed with local exhaust and resulted in personal TWA exposure of 1.3 ppm. Table 5 shows the additional results of the air monitoring.  

                     Table 5. C6 FK Air Monitoring Results
Scenario
                              Peak Concentration
                            Area TWA Concentration
Tote Filling -- no local exhaust
                                    300 ppm
                                    60 ppm
Drum Filling--with local exhaust
                                   11.7 ppm
                                    1.3 ppm

While the analysis performed by the submitter is intended for manufacturing and packaging of C7 FK for distribution, it is likely that similar exposure scenarios would exist during filling of streaming systems containing C7 FK.  As such, certain precautions should be taken regarding the peak exposure values that may result if a spill occurs during filling and maintenance of these systems. Based on the submitter's analysis, it is recommended to have adequate ventilation, such as that provided by local exhaust fans, in establishments where filling and maintenance activities for streaming systems are carried out. Filling operations should be performed in areas with additional exposure controls, including reduced fill drop height, slower fill rate, and smaller containers. The manufacturer has recommended use of OSHA Category D or higher PPE, such as safety goggles with side shields and neoprene, nitrile rubber, or polymer laminate gloves, for workers dealing with C7 FK in industrial settings. In addition, all spills should be cleaned up immediately in accordance with good industrial hygiene practices and the MSDS for C7 FK, and training for safe handling procedures should be provided to all employees that would be likely to handle the containers of C7 FK or portable extinguishing units filled with the material. 

6.	END-USE EXPOSURE ASSESSMENT
C7 FK is expected to be used as a streaming agent in portable fire extinguishers for the industrial, commercial, and military sectors. It is not intended for residential or direct consumer use. C7 FK is designed as a clean extinguishing agent that discharges as a vapor and can be removed through normal ventilation. 

According to OSHA (Hazard Communication Standard 29 CFR 1910.1200(f)(1)), all portable fire extinguishers must have a label identifying the material and issuing appropriate hazard warnings. Following discharge of a portable fire extinguishing unit containing C7 FK, fire fighters and other end-users are expected to follow the warnings on the label. If the extinguisher is discharged, it is expected that the room would be evacuated until ventilation systems reduce airborne concentrations of the C7 FK agent below the recommended occupational exposure limit. 

To give guidance to fire fighters and other end-users and to assess exposure and toxicity concerns associated with use of a proposed Halon 1211 substitute as a streaming agent, the submitter modeled two scenarios to determine the appropriate ventilation and reentry time after complete discharge of a C7 FK portable extinguishing unit. The submitter compared the results of both scenarios to the 8-hour AEL for C7 FK (225 ppm) and reentry times were established. In both scenarios, the ventilation rate was fixed at 6 air changes per hour (ACH) and 10 lbs (4.5 kg) of C7 FK, the full charge of a C7 FK extinguisher, was discharged (3M 2011a). The peak concentrations in both scenarios were greater than the AEL and recommended reentry times were established when the room concentration returned to levels below the AEL (see Table 6).

                      Table 6. C7 FK Discharge Monitoring
                             Scenario Room Volume
                              Peak Concentration
                                 Reentry Time
                                Exposure Limit
                                   100 m[3]
                                   3,000 ppm
                                    26 min
                              225 ppm (8-hr AEL)
                                   1000 m[3]
                                    300 ppm
                                     3 min
                                       

These reentry times were established using the 8-hour AEL. If the peak concentrations in the room for the two modeled scenarios were compared to a 5-minute acute AEL (21,600 ppm), reentry would be permitted much earlier. 

Though PPE is not required for incidental exposures that may occur during normal discharge of a portable unit due to C7 FK's low acute toxicity, the use of PPE is recommended for fire fighters using C7 FK in accordance with the MSDS for C7 FK, including full protective equipment (Bunker Gear) and a self-contained breathing apparatus (SCBA) to protect against the effects of thermal decomposition products of C7 FK (3M 2011b). In addition, use of C7 FK is subject to the requirements of other organizations including NFPA, Underwriters Laboratories, and OSHA. 
7.	GENERAL POPULATION EXPOSURE ASSESSMENT
C7 FK is not expected to cause a significant risk to human health in the general population when used as a streaming agent in portable fire extinguishers, and it is not intended for residential or direct consumer use. The following sections discuss the potential effects of C7 FK on ambient air, surface water, and as solid waste. 

7.1 	Ambient Air
C7 FK is expected to degrade via direct photolysis. The formation of breakdown products is not considered to be a toxicological concern, and their formation is expected to contribute only miniscule amounts to ambient air or rainwater.  Thus, use of C7 FK as a streaming agent is not expected to pose a risk to the general population.
7.2 	Surface Water
As discussed in the Background Document, the physicochemical properties of the majority of halon substitutes make it unlikely that the substitutes would be released to surface water as a result of use.  In the case of C7 FK, the proposed substitute is insoluble in water and has a very high Henry's Law Constant, meaning the compound readily volatilizes. Thus, it is expected that all of the constituents would rapidly vaporize during expulsion from the container and therefore would not be likely to settle or to lead to surface water contamination (3M 2010b). 
7.3 	Solid Waste
As discussed above, C7 FK will vaporize upon discharge.  Therefore, use of this agent is not expected to generate solid waste. To the extent that solid materials are used in post-activation clean-up procedures, clean-up residues should be disposed of in accordance with the C7 FK MSDS. 
8. 	VOLATILE ORGANIC COMPOUND ASSESSMENT
C7 FK has not been exempted as a VOC under the CAA (40 CFR 51.000). VOC emissions should be sufficiently controlled through standard industry practices. VOC emissions from the production of portable extinguishers charged with C7 FK are controlled through standard industry practices, and as such, emissions from manufacture of units are likely to be minimal.  Using release estimates from the Vintaging Model, the annual release rate (including discharge, leak, and training release rates) for portable extinguishers was calculated to be approximately 3.5% of extinguisher charge size. Assuming this release rate, an assessment was performed to compare the annual VOC emissions from use of C7 FK in portable extinguishers in one year to other anthropogenic sources of VOC emissions. Assuming the portion for streaming agent applications of the submitter's maximum allowable annual production, only approximately 1.0x10[-3] percent of the annual VOC emissions caused by fires,  or only about 3.8x10[-][5] percent of all annual anthropogenic VOC emission sources would be released from the charged portable extinguishers.  Moreover, even if the entire portion for streaming agent applications of the allowable quantity of C7 FK produced by the submitter in one year was all released to the atmosphere (extremely unlikely), the resulting VOC emissions would be approximately equal to 3.0x10[-][2] percent of annual VOC emissions caused by fires, or only about 1.1x10[-][3] percent of all annual anthropogenic VOC emissions.  As these emissions are several orders of magnitude less than other anthropogenic emissions, the environmental impacts of these VOCs are not considered a significant risk.

9.	REFERENCES						
3M 2001.  SNAP Submission to EPA for Novec 1230.  January 3, 2001.

3M 2010a. SNAP Addendum to EPA for C7 FK. February 22, 2010.

3M 2010b. P-10-135  -  C7 FK (Fluoroketone) teleconference EPA/3M Summary. November 22, 2010.

3M 2011a. Response to Incomplete SNAP submission for Fluoroketone. February 17, 2011.

3M 2011b. Safety Data Sheet  -  L-20154 Development Material. Issued August 11, 2011.

Alexeeff, George V., John D. Budroe, James F. Collins, Richard H.F. Lam, David C. Lewis, Michael J. Lipsett, Melanie A. Marty, and Thomas R. Parker. 1999. "Determination of Acute Reference Exposure Levels for Airborne Toxicants." Office of Environmental Health Hazard Assessment. March 1999.

EPA 1994. "Risk Screen on the Use of Substitutes for Class I Ozone-depleting Substances:  Fire Extinguishing and Protection (Halon Substitutes)," U.S. Environmental Protection Agency, March 1994.
EPA 2008. 2005 National Emissions Inventory Data & Documentation. Inventory Data: 42 Category Summaries. Last updated 6 July 2010. Accessed 20 September 11. Available online at <http://www.epa.gov/ttn/chief/net/2005inventory.html#inventorydata>.
EPA 2009.  Volatile Organic Compounds  -  National Summary of VOC Emissions.  Last updated 04 November 2009.  Accessed 16 May 2011. Available at <http://www.epa.gov/air/emissions/voc.htm>.
EPA 2011. The National Emissions Inventory. 2008 National Inventory Data. Last updated 19 July 11. Accessed 20 September 11. Available online at <http://www.epa.gov/ttn/chief/net/2008inventory.html>.
ICF 2011.  Determination of an Acceptable Exposure Limit for C7 Fluoroketone.  May 2011.  

	

 

      

                                       
                                  Appendix A
              Determination of an AEL for C7 Fluoroketone (C7 FK)
                                       
Recommended AEL: 		225 ppm (8-hour)				
	
Basis and Endpoints: 		NOAEL 3000 ppm for male rats 

Study: 	Sub acute (29-day) Inhalation Toxicity Study with MTDID 10800 in Rats

Protocol:	6 hours/day, 5 days/week for 4 weeks (whole body exposure)

Concentrations:			0; 3,000; 7,500; 15,000 ppm 

NOAEL:	3,000 ppm (males) (excluding peroxisomal proliferation) 

Uncertainty Factor:	10 (3 - interspecies extrapolation; 3  -  use of a sub-acute study)

AEL 	225 ppm (= 3,000 * 6 hours (exposure of rats)/8 hours (workday))* (1/10)

Derivation of a preliminary AEL for C7 FK relies on the reported NOAEL of 3,000 ppm for male Wistar rats from the 29-day inhalation study at exposure doses of 0, 3,000, 7,500, and 15,000 ppm (Muijser and Staal, 2008).  The only exposure-related effects of note in male rats were peroxisomal proliferation in liver cells at all exposure concentrations, and a significant increase in hepatocellular hypertrophy, as well as significant increases in the number of total white blood cells, lymphocytes, and neutrophils at 7,500 and 15,000 ppm.  No other effects in males were found by histological examination.  All the reported effects were found to be reversed in a separate group of recovery males who were held for 13-days post exposure.  No exposure-related effects were noted in female rats at any concentration; thus the NOAEL for females was identified as 15,000 ppm.  Peroxisomal proliferation is common in male rats which have been exposed to certain toxicants, and the effect has been debated within the risk assessment community with regard to predicting liver toxicity in humans (Keshava and Caldwell 2006; Melnick 2001).  The study authors discounted the peroxisomal proliferation, and identified a NOAEL of 3,000 ppm based on other mild responses at the mid- and high concentrations.  ICF agrees with this decision, particularly given the reversibility of the effects and given the similarity in the toxicity of C7 FK with the structurally similar C6 FK.

 Compensation for 6 hour/day exposure for 5 days/week is accomplished by multiplying the AEL of 3,000 ppm by a factor of 0.75 (6 hour study exposure/ 8 hour typical worker exposure) to obtain a Human Equivalent Concentration (HEC) of 2,250 ppm. An interspecies uncertainty factor of 3 is used to account for the pharmacodynamic differences between rats and humans. An additional uncertainty factor of 3 is recommended to compensate for use of a 29-day, rather than 90-day subchronic or 2-year chronic, study to develop the 8-hour AEL. The supporting toxicological data for C6 fluorinated ketone (C6 FK), which is structurally similar to C7 FK, precludes the need for an additional UF for the quality of the database.  Division of the HEC by 10 (multiplicative value of uncertainty factors) produces a derived AEL for C7 fluorinated ketone of 225 ppm.  
References

Keshava N and JC Caldwell (2006) Key issues in the role of peroxisome proliferator-activated receptor agonism and cell signaling in trichloroethylene toxicity.  Environ Health Perspect 114(9):1464-1470.
Melnick RL (2001) Is peroxisome proliferation an obligatory precursor step in the carcinogenicity of di(2-ethylhexyl)phthalate (DEHP)? Environ Health Perspect 109(5):437-442.

Muijser H. and Staal YCM. (2008) Sub-acute (29-day) inhalation toxicity study with MTDID 10800 in rats. TNO Quality of Life, The Netherlands, for 3M Company, St Paul, MN 17 December