Global Warming Potential

Perfluorotributyl Amine (PTBA) (CAS Number: 1064698-37-8)

Summary: 

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

(GWP) for Perfluorotributyl Amine (PTBA). The format of this report is consistent with 

submittals to EPA for the use of Provisional GWP’s. 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 GWP’s can be used 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 support such a lower value. 

Table A–1 does not list a GWP for PTBA. As described in greater detail in a subsequent 

section, the atmospheric lifetime of PTBA has been estimated as 400 years [3]; the radiative 

forcing of PTBA has been estimated as 1.05 W/m2/ppbv [3] and the GWP of PTBA has been 

estimated as 9020 relative to CO2 with a 100-year integration time horizon. 

Evidence Supporting Request: 

F-GHG Identity: perfluorotributyl amine (PTBA) 

Chemical Formula: C12F27N

CAS Number: 1064698-37-8 

Estimated GWP: 9020 relative to CO2 with a 100-year integration time horizon 

Data and analysis: Atmospheric and Environmental Research (AER) measured the kinetic 

rate constants for the vapor phase reaction of PTBA with •OH and O(1D) [3], significant 

degradation was not observed. Given the configuration of the experimental apparatus and the 

performance of the analytical equipment, the longest atmospheric lifetime that could be 

observed in their experimental system was >390 years. Based on this observation the 

atmospheric lifetime was estimated as 400 years. The authors did note some degradation of 

PTBA in control experiments and hypothesized that direct photolysis may have occurred at a 

wavelengths near 222 nm. Thus the actual atmospheric lifetime of PTBA may be further 

limited by direct photolysis mechanism. 

Radiative forcing: Band by band absorption cross-sections were obtained from averaged IR 

spectra. Radiative forcing was calculated by a consultant using an internal model (AER 1-D 

RC) [3] and used to calculate a direct, equilibrium surface temperature response (∆T) 

assuming a 1 ppbV introduction. The IR spectrum for PTBA from that report is provided in 

Figure 1. The corresponding value relative to CFC-11 on a per-molecule basis was reported 

as 4.20. This value converted to a radiative forcing using the known value for CFC-11 (0.25 

W/m2/ppbv) reported in [4]. Radiative forcing for PTBA is 1.05 W/m2/ppbV. 
Using these data in the equation referenced by the IPCC [4] to determine the GWP of a given 

substance, a GWP of 9020 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. Ko, M.K.W. and D.T. Chang, Estimates of the Global Warming Potential of Proposed 

Chemical Compounds. 1992, Atmospheric and Environmental Research, Inc.: Cambridge, 

MA 

5. 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 

Figure 1. FTIR Reference Spectrum for perfluorotributylamine (PTBA)