MEMORANDUM 

 

To: Erin Birgfeld 

Cc: Bella Maranion 

From: Sarah Percy, Mark Wagner 

Date: September 10, 2003 

Re: Re-evaluation of a C-6 Oxyfluorocarbon (trade name Novec 1230) and References 

Deliverable under EPA Contract Number 68-D-00-266, Work Assignment 2-05 Task 03 

Based on analysis developed by ICF’s subcontractor, Dr. Don Wuebbles, please find a 

revised discussion of the atmospheric lifetime and Global Warming Potential (GWP) for 

C-6 oxyfluorocarbon. This memorandum presents a review of the literature that 

supported the GWP and ALT evaluation conducted in January of 2003. Additionally, a 

revised assessment of the GWP based on the mass of C-6 oxyfluorcarbon and CO2 is 

provided. Please contact Mark Wagner at (202) 862-1155 if you have any questions. 

Summary 

Based on an analysis of the C-6 oxyfluorocarbon, derived using the IPCC recommended 

approach for such assessments, it was determined that the chemical has an atmospheric 

lifetime of up to two weeks and a GWP of between 0.6 and 1.8. 

Discussion of Results 

The previous examination of the C-6 oxyfluorocarbon, trade name Novec 1230 

(CF3CF2C=OCFCF3CF3), was conducted in October 2002 without the review of any 

literature that could directly aid in the determination of the atmospheric lifetime or 

radiative forcing on climate associated with this compound. Using the IPCC approach, it 

was concluded that absorption of solar radiation for photodissociation of the 

oxyfluorocarbon would likely be in the 250-350 nm region, implying a lifetime of days 

up to as much as a year, with the lifetime most likely much shorter than a year. Based on 

this, the concluded 100-year integration GWP for the C-6 oxyfluorocarbon would range 

from a value of 6, based on the reaction products producing six carbon dioxide 

molecules, up to 100, accounting for a lifetime as long as one year. 

In January 2003, three additional papers on C-6 oxyfluorocarbon photolysis were 

reviewed. The first of these, and the most credible, Taniguchi et al. (2003), published in 

the Journal of Physical Chemistry A, deals with the reaction of the C-6 oxyfluorocarbon 

in the atmosphere and associated reaction products. This paper concludes that photolysis 

is the significant reaction. Taniguchi et al. found that the photolysis quantum yield for the 

C-6 oxyfluorocarbon is significantly less than unity. The paper concludes that the 

atmospheric lifetime due to photolysis will be 1-2 weeks, and suggests the need for 
further study. However, the authors also suggest that one of the products, CF3COF, 

would be water soluble and subject to rainout. This means as many as two of the carbons 

could get washed out and not become carbon dioxide in the atmosphere. The other four 

carbons would likely result in atmospheric carbon dioxide. In addition, whatever C-6 

oxyfluorocarbon, and therefore CF3COF, is transported into the free troposphere outside 

of cloud regions may also result in atmospheric carbon dioxide. The net result is that 4+ 

carbons in the C-6 oxyfluorocarbon would eventually result in carbon dioxide in the 

atmosphere. 

The second paper, Guschin et al. (1999), makes a rough estimate of the atmospheric 

lifetime of the C-6 oxyfluorocarbon by comparing its ultraviolet and visible absorption 

spectra to acetaldehyde, and suggests that this comparison implies an atmospheric 

lifetime for the C-6 oxyfluorocarbon of 5 days. However, this is only a crude estimate 

and does not take into account the quantum yields measured in the much later work by 

Taniguchi et al. This implied 5-day lifetime was then used in a paper entitled, Global 

Warming Potentials of 3M Novec 1230 Fire Protection Fluid, author unknown, to 

estimate a100-year integrated GWP of 1.0. Additionally, this paper assigns a radiative 

forcing of 0.50 Wm-2 ppbv-1. 

The evaluation of the radiative forcing is based on the approach used by Pinnock et al. 

(1995). However, Pinnock et al. assumes a constant mixing ratio for the substance in both 

the troposphere and stratosphere, which would most certainly not be the case for the C-6 

oxyfluorocarbon. This assumption is not valid for C-6 oxyfluorocarbon and the radiative 

forcing would likely be smaller. This implies a much smaller GWP except that the 

assumed lifetime is too small based on the analysis of Taniguchi et al. 

In conclusion, the new information found in the literature suggests that the original GWP 

estimate should be revised. The direct GWP for a 100-year integration, calculated using 

the IPCC approach (originally developed by Dr. Don Wuebbles), would likely have a 

value of 1 or less. This is based on the atmospheric lifetime of up to two weeks (instead 

of 5 days), but with the radiative forcing likely much less than 0.50 Wm-2 ppbv-1, because 

of the expected rapid fall off in mixing ratio of the C-6 oxyfluorocarbon with altitude. In 

addition, however, one must consider and add in the GWPs of any reaction products that 

are sufficiently long-lived. As stated above, 4+ CO2 molecules will be produced and enter 

into the atmosphere as a result of the photodissociation of the C-6 oxyfluorocarbon. By 

definition, the GWP of each of these is 1. Therefore, depending on the exact value of the 

direct GWP of the C-6 oxyfluorocarbon and the amount of CF3COF actually rained out, 

the total GWP for the C-6 oxyfluorocarbon and its products will be greater than 4 to as 

high as 7. In accordance with its definition, the GWP has been further revised and 

evaluated to account for mass1

. Multiplying the direct and indirect GWP’s by the ratio of 

CO2 mass to C-6 oxyfluorocarbon mass results in a 100 year GWP for C-6 

oxyfluorcarbon between 0.6 and 1.8. The total GWP is comprised of a direct value of 

less than 1 but greater than zero plus an indirect GWP of 0.56 to 0.84, based on 4 to 6 

carbons available for conversion to CO2. 

 

1

 The definition of GWP can be found at 

<http://yosemite.epa.gov/oar/globalwarming.nsf/content/EmissionsNationalGlobalWarmingPotentials.htm> 
Finally, although it has not yet been adopted by IPCC, the direct GWP for short-lived 

gases like this C-6 oxyfluorocarbon would depend on where and when the emissions 

occurred. Thus, the direct GWPs, just like ODPs for short-lived gases (e.g., see 

Wuebbles, et al., 2001), would depend on what region or at which latitude the emissions 

occurred. This, however, should have a very minimal effect for the C-6 oxyfluorocarbon, 

in question. 

References 

Guschin, A. G.; Molina, L.T.; and Molina, M.J. (1999). Atmospheric Chemistry of L15381, L-15566 and L-14703 and Integrated Band Strengths of L-14374, L-14375, L14752, L-13453 and L-14703. Report prepared for 3M Specialty Chemicals Division 

Laboratory, St. Paul, Minnesota. 

Pinnock, S.; Hurley, M.D.; Shine, K.P.; Wallington, T.J.; Smyth, T.J. (1995). Radiative 

forcing by hydrochlorofluorocarbons and hydrofluorocarbons. J. Geophys. Res., 100, 

23227-23238. 

Taniguchi, N.; Wallington, T.J.; Hurley, M.D.; Guschin, A.G.; Molina, L.T. (2003). 

Atmospheric Chemistry of C2F5C(O)CF(CF3)2: Photolysis and Reaction with Cl 

Atoms, OH Radicals, and Ozone. J. Phys. Chem. A., 107(15); 2674-2679. 

Wuebbles, D. J.; Patten, K.O.; Johnson, M.T.; and Kotamarthi, R. (2001). The new 

methodology for Ozone Depletion Potentials of short-lived compounds: n-propyl 

bromide as an example. J. Geophys. Res., 106, 14551-14571.