# Commission Delegated Regulation (EU) 2019/331 of 19 December 2018 determining transitional Union-wide rules for harmonised free allocation of emission allowances pursuant to Article 10a of Directive 2003/87/EC of the European Parliament and of the Council (Text with EEA relevance), Division 1: Where data for a specific data set are not available for each sub-installation, the operator shall propose an appropriate method for determining the required data for each individual sub-installation, except for cases referred to in the second and third subparagraphs of Article 10(3). For this purpose, either of the following principles shall be applied depending on which principle yields more accurate results:

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

(a)where different products are produced one after the other in the same production line, inputs, outputs and corresponding emissions shall be attributed sequentially based on the usage time per year for each sub-installation;
(b)inputs, outputs and corresponding emissions shall be attributed based on the mass or volume of individual products produced or estimates based on the ratio of free reaction enthalpies of the chemical reactions involved or based on another suitable distribution key that is corroborated by a sound scientific methodology.

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Source: https://www.legislation.gov.uk/eur/2019/331/annex/VII/division/3/division/3.2/division/1 (the official version)
Page: https://openlegislation.uk/eu-regulation-2019-331/annex-VII/division-3/division-3.2/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.