Request to Use an Alternate GWP for

Perfluoropropyl vinyl ether (CAS Number: 1623-05-8)

Summary:

EPA recently promulgated a mandatory reporting regulation for Fluorinated Greenhouse 

Gases (F-GHG). The regulation 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 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] A 

default GWP value of 2,000 is to be used for any F-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 perfluoropropyl vinyl ether. Perfluoropropyl vinyl 

ether is a short-lived fluorinated vinyl ether. The default GWP value of 2,000 is 

inappropriate for such gases and a substantial body of evidence in the peer-reviewed 

scientific literature has established that the GWPs of fluorinated vinyl ethers are modest. 

The atmospheric lifetime of perfluoropropyl vinyl ether has been estimated as 8.077 days

using the AOPWIN module of EPA’s EPI SuiteTM v4.10 exposure assessment modeling 

tool; the infrared spectrum of perfluoropropyl vinyl ether has been accurately estimated 

using ab initio quantum chemical methods recommended in the peer-reviewed scientific 

literature and the GWP of perfluoropropyl vinyl ether has been estimated as 3 relative to 

CO2 with a 100-year integration time horizon. DuPont is requesting a provisional 

GWP of 3 be assigned for perfluoropropyl vinyl ether.

Evidence Supporting Request:

F-GHG Identity: Perfluoropropyl vinyl ether

Chemical Formula: C5OF10

CAS Number: 1623-05-8

Estimated GWP: 3 relative to CO2 with a 100-year integration time horizon 

Data and analysis: A global and yearly averaged atmospheric lifetime for 

perfluoropropyl vinyl ether of 8.077 days was estimated using the AOPWIN module of 

EPA’s EPI SuiteTM v4.10 exposure assessment modeling tool. [3] 

For comparison, Mashino et al. have measured kinetic rate constants for the vapor phase 

reaction of the chemically very similar perfluoromethyl vinyl ether with OH. [4] OH 

radicals react with perfluoromethyl vinyl ether with a rate constant of (2.6 ± 0.3) × 10−12

cm3 molecule−1s

−1 at 296 K in 700 Torr of air. The global and yearly averaged

atmospheric lifetime of perfluoromethyl vinyl ether was estimated by scaling to the 
known lifetime of methyl chloroform. This approach gives an atmospheric lifetime of 

perfluoromethyl vinyl ether with respect to reaction with OH of 0.023 years (8 days). 

Thus the lifetime of 8.077 days obtained for perfluoropropyl vinyl ether using AOPWIN 

is reasonable. Infrared cross-sections of perfluoropropyl vinyl ether were obtained using 

ab initio quantum chemical methods recommended in the peer-reviewed scientific 

literature. [5-6] Radiative forcing calculations were performed using the approximation 

method developed by Pinnock et al. [7] Using this approach, a GWP for 

perfluoropropyl vinyl ether of 3 relative to CO2 with a 100-year integration time horizon 

was established. 

The methods used in determining this GWP value are essentially identical to those used 

for the values obtained for the gases listed in Table A-1: (1) the kinetic rate constants for 

reaction with critical atmospheric oxidants were measured and an atmospheric lifetime 

was determined; (2) the infrared absorption spectrum of the substance was measured; and 

(3) the atmospheric lifetime and infrared absorption spectrum were incorporated into a 

radiative transfer model to estimate the contribution of the substance to greenhouse 

forcing. 

Based on this publication in the peer-reviewed literature, DuPont requests that a 

provisional GWP of 3 be assigned for perfluoropropyl vinyl ether.

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. EPI SuiteTM v4.10, EPA Office of Pollution Prevention & Toxics and Syracuse 

Research Corporation (2000-2008).

4. Mashino, M., et al., Atmospheric Degradation of CF3OCFCF2: Kinetics and 

Mechanism of Its Reaction with OH Radicals and Cl Atoms. The Journal of 

Physical Chemistry A, 2000. 104(13): p. 2925-2930.

5. Blowers, P. and K. Hollingshead, Estimations of Global Warming Potentials from 

Computational Chemistry Calculations for CH2F2 and Other Fluorinated Methyl 

Species Verified by Comparison to Experiment. The Journal of Physical 

Chemistry A, 2009. 113(20): p. 5942-5950.

6. Halls, M.D. and H.B. Schlegel, Comparison of the performance of local, 

gradient-corrected, and hybrid density functional models in predicting infrared 

intensities. The Journal of Chemical Physics, 1998. 109(24): p. 10587-10593.

7. Pinnock, S., et al., Radiative forcing of climate by hydrochlorofluorocarbons and 

hydrofluorocarbons. Journal of Geophysical Research, 1995. 100(D11): p. 23227-

23238.