Declaration 3 of the 17th CCQM (2011)

On the need for further consultation over the possible redefinition of the mole

The Consultative Committee for Amount of Substance – Metrology in Chemistry (CCQM),


  • the importance of both the mole and the kilogram to the chemical measurement community,


  • that Resolution 12 adopted by the General Conference on Weights and Measures (CGPM) at its 23rd meeting (2007) recommended that National Metrology Institutes and the International Bureau of Weights and Measures (BIPM) “initiate awareness campaigns to alert user communities to the possibility of redefinitions and that the technical and legislative implications of such redefinitions and their practical realizations be carefully discussed and considered,
  • Recommendation Q 1 of the CCQM (2009): On the possible redefinition of the mole and the kilogram,
  • Draft Resolution A on the possible future revision of the International System of Units adopted by the International Committee for Weights and Measures (CIPM) in 2010 and to be submitted to the CGPM at its 24th meeting (2011),
  • that there is limited documented evidence of increasing awareness in the relevant communities of the proposal to redefine the mole,

decides to

  • prepare a mise en pratique for the possible future redefinition of the mole for circulation by the end of May 2011,

recommends its members to

  • identify the most influential national and international bodies with responsibility for chemical measurements, and particularly the teaching and standardization of chemical measurements,
  • ensure that these bodies are kept informed about the proposal to re-define the mole as published on the website of the BIPM in Draft Resolution A,
  • determine whether these bodies anticipate significant difficulties with implementing such a definition as early as 2015, in the light of the new mise en pratique,
  • report the results of their consultation activities to the 18th Meeting of the CCQM planned for April 2012,

invites the BIPM Director to write to the President of the International Union of Pure and Applied Chemistry (IUPAC) to acknowledge the resolution in support of a new definition of the mole of the IUPAC Interdivisional Committee on Terminology, Nomenclature and Symbols (ICTNS) and the Executive Committee, inform her about the re-drafted mise en pratique for the mole and invite her to inform the BIPM about progress with the consultation over this redefinition amongst the member bodies of the IUPAC.

DOI : 10.59161/CCQM2011DECL3E

The reader should note that the official version of this Resolution is the French text

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