# Directive 2006/40/EC of the European Parliament and of the Council of 17 May 2006 relating to emissions from air-conditioning systems in motor vehicles and amending Council Directive 70/156/EEC (Text with EEA relevance), Part 2: Method of calculating the total global warming potential (GWP) for a preparation

Extent: E+W+S+N.I.

The total GWP for a preparation is a weighted average, derived from the sum of the weight fractions of the individual substances multiplied by their GWPs.
Σ (Substance X % × GWP) + (Substance Y % × GWP) + … (Substance N % × GWP)
where % is the contribution by weight with a weight tolerance of +/- 1 %.
For example: applying the formula to a theoretical blend of gases consisting of 23 % HFC-32; 25 % HFC-125 and 52 % HFC-134a;
Σ (23 % × 550) + (25 % × 3 400) + (52 % × 1 300)
→ Total GWP = 1 652,5.

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Source: https://www.legislation.gov.uk/eudr/2006/40/annex/part/2 (the official version)
Page: https://openlegislation.uk/eu-directive-2006-40/annex/part-2
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.