Request to Use an Alternate GWP for

Perfluorotriamyl Amine (PTAA) (CAS Number: 338-84-1)

Summary: 

This document describes analysis conducted by 3M to determine a Global Warming Potential 

(GWP) for HFE-7500. The format of this report is consistent with submittals to EPA for the 

use of Provisional GWPs. The Mandatory Reporting Rule requires facilities to monitor and 

report CO2-equivalent F-GHG process vent emissions, if those emissions exceed a threshold 

of 10,000 metric tons CO2-equivalent per year. [1] Estimated CO2-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 individual F-GHG, and specifies that these 

values are to be used for the purpose of computing CO2-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 clear scientific evidence exists to support 

such a lower value. 

Table A–1 does not list a GWP for perfluorotriamyl amine (PTAA). As described in greater 

detail in a subsequent section, the atmospheric lifetime of perfluorotriamyl amine has been 

estimated as 2000 years; the radiative forcing has been estimated using a QSAR and the 

GWP of perfluorotriamyl amine has been estimated as 8900 relative to CO2 with a 100-year 

integration time horizon. 

Evidence Supporting Request: 

F-GHG Identity: perfluorotriamyl amine (PTAA) 

Chemical Formula: C15F33N

CAS Number: 338-84-1 

Estimated GWP: 8900 relative to CO2 with a 100-year integration time horizon 

Data and analysis: Molina et al. have measured kinetic rate constants for the vapor phase 

reaction of perfluorotriethyl amine with OH and O(1D) [3], and have estimated the 

atmospheric lifetime as >2000 years. The atmospheric lifetime of perfluorotriamyl amine 

was estimated as 2000 years based on the physical/chemical similarity with respect to the 

mode of atmospheric degradation between of perfluorotriethyl amine and perfluortriamyl 

amine. Both compounds are in the same class of compounds, namely perfluorinated amines 

and differ only in perfluorinated alkyl chain length. 

Radiative forcing was estimated using a QSAR model developed by 3M specifically for 

perfluorinated amines using measured data for perfluorinated amines as a QSAR model 

input. In one QSAR the estimated forcing of PTAA ((C5F11)3N) was estimated from the 

radiative forcing of PTPA (0.71 Wm-2ppbV-1) plus the forcing of 12 perfluoropropane C-F 

bonds (12 × 0.03 = 0.36 Wm-2ppbV-1) to yield a radiative forcing 1.1 Wm-2ppbV-1. In the 

second QSAR the radiative forcing was estimated from radiative forcing of PTBA (1.05 Wm2

ppbV-1) plus the forcing of 6 perfluoropropane C-F bonds (6 × 0.03 = 0.18 Wm-2ppbV-1) to 
yield a radiative forcing of 1.2 Wm-2ppbV-1. The average of these two radiative forcing 

estimates and rounding to two significant figures gives a radiative forcing of 1.2 Wm-2ppbV-1

for PTAA. 

Using these data in the equation referenced by the IPCC [4] to determine the GWP of a given 

substance, a GWP of 8900 relative to CO2 with a 100-year integration time horizon was 

established. 

1. "Mandatory Reporting of Greenhouse Gases: Additional Sources of Fluorinated GHGs; 

Final Rule", Federal Register 75:230 (December 1, 2010) p.74774. 

2. "Table A-1 to Subpart A of Part 98—Global Warming Potentials": 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. IPCC, 2007: Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution 

of Working Group II to the Fourth Assessment. Report of the Intergovernmental Panel on 

Climate Change, M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. 

Hanson, Eds., Cambridge University Press, Cambridge, UK, 976pp