Nitrogen trifluoride: the new mandatory Kyoto Protocol greenhouse gas

Big news in the realm of greenhouse gas accounting and reporting, folks: the UNFCCC, within the context of the Kyoto Protocol, has wisely decided to include nitrogen trifluoride (NF3) in the second Kyoto compliance period, which begins this year and ends in either 2017 or 2020. Following suit, the WBCSD/WRI’s GHG Protocol is amending all of its standards (corporate, product and Scope 3) to also cover NF3. Luckily for clients using Our Impacts, Ecometrica’s powerful and CDP-accredited greenhouse gas accounting solution, the capacity to measure and report emissions from this new seventh Kyoto gas has already been fully integrated.

Nitrogen trifluoride is an inorganic nitrogen-fluorine compound that acts as a replacement for PFCs, specifically hexafluoroethane (C2F6). It is used most frequently in the electronics industry during various processes including plasma etching, cleaning chambers in which silicon chips are made, and semi-conductor and LCD panel manufacture. Additionally, it has several important applications within the photovoltaic and chemical laser industries. Its 100-year global warming potential of 17,200 is second only to sulphur hexafluoride among the gases covered by the Kyoto Protocol, meaning that it is highly effective at trapping atmospheric heat, and it has a lifetime of 740 years.

The move to include nitrogen trifluoride is the result of research conducted by the IPCC, initially, into gases that were either less significant in terms of atmospheric concentration at the time of the adoption of the Kyoto Protocol or were developed afterwards. Nitrogen trifluoride is a perfect example of this first type of gas. Though the use of NF3 in the semiconductor industry began as far back as the late 1980s, C2F6 was the more traditional etchant and was not, at that time, monitored under the Kyoto Protocol. The result was that hexafluoroethane was used preferentially, and nitrogen trifluoride was much more peripheral.

However, since the adoption of the protocol, many companies within the above industries have switched over to using NF3 and, correspondingly, its usage and subsequent atmospheric concentrations have increased dramatically, especially in the last decade. This trend, coupled together with the fact that the release rate, based on recent studies, is likely significantly higher than the original estimates of between 2% and 5%, meant that NF3 was officially on the radar. As a result of its chemical properties and the significant increase in its usage, the IPCC published an updated version of Table 2.14 from the 4th Assessment Report in 2008 that included, among other additional gases, NF3. Technical information on these new species was compiled in 2010 by the Ad hoc Working Group on Further Commitments from Annex I Parties under the Kyoto Protocol (AWG-KP) and, using this information and feedback from multiple stakeholders, the decision to include it in the second compliance period was made.

Following in the UNFCCC’s footsteps, the WBCSD/WRI announced last month that it would be updating its corporate, product and Scope 3 accounting standards to require the measurement and reporting of nitrogen trifluoride. The choice is logical, since it will preserve consistency between national and organizational emissions accounting. Given the typical uses of NF3, the change is unlikely to affect most non-industrial companies and organizations, but it’s worth your while to review the processes within your organization to ensure that your future assessments are in compliance. The open comment period on the proposed update ended July 29, and the amendment is likely to be officially adopted by the end of August. The updated guidance will apply to all new inventories prepared for the next year of reporting that are seeking compliance with a WBCSD/WRI standard.

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