### Global Warming Potential

1,1,1,2,2,3,4,5,5,5-decafluoro-3-methoxy-4-trifluor omethyl-pentane

(HFE-7300) (CAS Number: 132182-92-4) Summary:

This document describes analysis conducted by 3M to determine a Global Warming Potential (GWP) for HFE-7300. The format of this report is c onsistent with submittals to EPA for the use of Provisional GWPs. The Mandatory Reporting R ule requires facilities to monitor and report CO 2 -equivalent F-GHG process vent emissions, if those emissions exceed a threshold of 10,000 metric tons CO 2 -equivalent per year. [1] Estimated CO 2 -equivalent emissions are obtained by multiplying the F-GHG mass emissions by the Global Warming Potential (GWP) for the individual fluorinated gases that comprise the flow. EPA has provided a table of 100- year time horizon GWP values for about 70 individua l F-GHG, and specifies that these values are to be used for the purpose of computing CO 2 -equivalent emissions. [2] Default GWPs can be used for any fluorinated-GHG not listed in Table A-1. The regulation allows a facility to request a lower provisional GWP when cl ear scientific evidence exists to support
such a lower value.

Table A–1 does not list a GWP for 1,1,1,2,2,3,4,5,5 ,5-decafluoro-3-methoxy-4- trifluoromethyl-pentane (HFE-7300). As described in greater detail in a subsequent se ction, the atmospheric lifetime of 1,1,1,2,2,3,4,5,5,5-dec afluoro-3-methoxy-4-trifluoromethylpentane has been determined to be 3.8 years based u pon laboratory measurements. The radiative forcing of 1,1,1,2,2,3,4,5,5,5-decafluoro -3-methoxy-4-trifluoromethyl-pentane has been calculated from a quantitative infrared spectr um and the GWP of 1,1,1,2,2,3,4,5,5,5- decafluoro-3-methoxy-4-trifluoromethyl-pentane has been estimated as 310 relative to CO 2 with a 100-year integration time horizon.

Evidence Supporting Estimated GWP:

F-GHG Identity: 1,1,1,2,2,3,4,5,5,5-decafluoro-3-me thoxy-4-trifluoromethyl-pentane (HFE-7300)

Chemical Formula: CF 3 CF 2 CF(OCH 3 )CF(CF3) 2

CAS Number: 132182-92-4

Estimated GWP: 310 relative to CO 2 with a 100-year integration time horizon

Data and analysis: Guschin et al. have measured kinetic rate constants for the vapor phase reaction of 1,1,1,2,2,3,4,5,5,5-decafluoro-3-methox y-4-trifluoromethyl-pentane with OH using a relative rate technique [3], resulting in an atmospheric lifetime calculate d at 3.8 years.

Quantitative infrared spectra were measured for HFE -7300, an example of which is shown in Figure 1. The instantaneous forcing was calculated from these spectra using the approximation method developed by Pinnock et al. [4] as 0.52 Wm -2 ppbv -1 . This calculation assumes that there is a constant concentration prof ile of the compound at all altitudes. To correct for this, the value was multiplied by a sca ling factor as suggested by Sihra et al. [5] to
account for the uneven vertical distribution of thi s compound in the atmosphere, resulting in a final radiative forcing value of 0.44 Wm -2 ppbv -1

.Using these data in the equation referenced by the IPCC [6] to determine the GWP of a given

substance, a GWP of 310 relative to CO 2 with a 100-year integration time horizon was
established.

1. "Mandatory Reporting of Greenhouse Gases: Additiona l Sources of Fluorinated GHGs;
Final Rule" , Federal Register 75:230 (December 1, 2010) p.7477 4.

2. "Table A-1 to Subpart A of Part 98—Global Warming P otentials" : Table A-1 in 40 CFR part 98, subpart A.

3. 

### Guschin, A.G., Molina, L.T. and Molina, M.J., Atmospheric Chemistry of Some Fluoroethers (L-14787) , Massachusetts Institute of Technology, report pre pared for 3M Company, May 1998, Cambridge, MA.

4. Pinnock, S., et al., Radiative forcing of climate by hydrochlorofluoroca rbons and hydrofluorocarbons. Journal of Geophysical Research, 1995. 100 (D11): p. 23227-23238.

5. Sihra, K., et al., Updated radiative forcing estimates of 65 halocarbo ns and nonmethane hydrocarbons , Journal of Geophysical Research, 2001. 106 (D17): p. 20493-20505.

6. IPCC, 2007: Climate Change 2007: Impacts, Adapt ation and Vulnerability. Contribution of Working Group II to the Fourth Assessment. Repor t of the Intergovernmental Panel on Climate Change, M.L. Parry, O.F. Canziani, J.P. Pal utikof, P.J. van der Linden and C.E. Hanson, Eds., Cambridge University Press, Cambridge , UK, 976pp.

### Figure1. FTIR Reference Spectrum of HFE-7300 0 .05 .1 .15

4500 4000 3500 3000 2500 2000 1500 1000

Absorbance / Wavenumber (cm-1) Paged X-Zoom CURSOR

File # 4 : 29HFE7300 6/4/2009 3:32 PM Res=None

HFE-7300 29.1 ppmM, 26.7 C, 1 atm, 128 scans, inst. T, 6/4/09, avg 29HFE7300a, 29HFE7300b