### Global Warming Potential

Perfluorotripropyl amine (PTPA) (CAS Number: 338-83 -0)

Summary: This document describes analysis conducted by 3M t o determine a Global Warming Potential (GWP) for Perfluorotripropyl Amine (PTPA) . The format of this report is consistent with submittals to EPA for the use of Pr ovisional GWP’s. The Mandatory Reporting Rule requires facilities to monitor and r eport 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 t he 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 individual F-GHG, and specifies that these value s are to be used for the purpose of computing CO 2 -equivalent emissions. [2] Default GWP’s can be use d for any fluorinatedGHG not listed in Table A-1. The regulation allows a facility to request a lower provisional GWP when clear scientific evidence exists to suppor t such a lower value. Table A–1 does not list a GWP for perfluorotripropy l amine. As described in greater detail in a subsequent section, the atmospheric lifetime o f perfluorotripropyl amine has been estimated as 2000 years; the infrared spectrum of p erfluorotripropyl amine has been accurately measured and the GWP of perfluorotriprop yl amine has been estimated as 8690 relative to CO 2 with a 100-year integration time horizon.

Evidence Supporting Request: F-GHG Identity: perfluorotripropyl amine (PTPA)

Chemical Formula: C 9 F 21 N

CAS Number: 338-83-0

Estimated GWP: 8690 relative to CO 2 with a 100-year integration time horizon Data and analysis: Tang has measured kinetic rate constants for the vapor p hase reaction of perfluorotriethyl amine with OH and O 3 [3], and have estimated the atmospheric lifetime as >2000 years. The atmospheric lifetime of perfluoro tripropyl amine was estimated as 2000 years based on the physical/chemical similarity wit h respect to the mode of atmospheric degradation between of perfluorotriethyl amine and perfluorotripropyl amine. Both compounds are in the same class of compounds, namel y perfluorinated amines and differ only in perfluorinated alkyl chain length. Infrared spectra were measured for perfluorotriprop ylamine using methodology recommended by Pinnock et al . [4] and referenced by the IPCC [5]. (see Figure 1 ) Radiative forcing calculations were performed using the appro ximation method developed by Pinnock et al. [4]. The radiative forcing was also estimated usin g a QSAR developed for perfluorinated amines. The average of the two valu es was 0.71 Wm -2 ppbv -1 and the difference between the two values was < 1%. Using the average radiative forcing in theequation referenced by the IPCC [5] to determine th e GWP of a given substance, a GWP of

8690 relative to CO 2 with a 100-year integration time horizon was establ ished.

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. Tang, Yi, Atmospheric Fate of Various Fluorocarbons . Master’s Thesis, Massachusetts Institute of Technology, 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. IPCC, 2007: Climate Change 2007: Impacts, Adapta tion 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



### Figure 1. FTIR Reference Spectra of PTPA.

0 .05 .1 .15 .2

4500 4000 3500 3000 2500 2000 1500 1000

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

File # 1 : 28PT PA 5/18/2009 3:38 PM Res=None

Perfluorotripropylamine 28.1 ppmM, 25.7 C, 1 atm, 1 28 scans, inst.T, 5/18/09, avg 28PTPAa, 28PT PAb