In the Pharmacopeial Forum 38/5 two proposals have been published about the revision of the two General Chapters on analytical balances.
It is planned to replace the title of General Chapter <41> "Weights and Balances" by "Balances" and also to revise General Chapter <1251> "Weighing on an Analytical Balance".
Chapter <1251> provides background information and advice regarding the qualification of analytical balances - also in concrete terms for OQ and PQ including possible tests. Unlike General Chapter <41>, Chapter <1251> isn't binding.
Regarding the fundamental approach for qualification it is referred to USP Chapter <1058> on Analytical Instrument Qualification.
In the future, the USP requirements on analytical balances will be slightly modified. The new USP requirements apply to all balances used for materials that must be "accurately weighed" (according to General Notices, 8.20).
Among other things the repeatability requirement has been changed from 0.1% to 0.10% in order to reflect current metrology practices.
A test weight should have a nominal mass between 5% and 100% of the balance's capacity.
Both the current USP requirements on Analytical Instrument Qualification and the concrete guidelines regarding handling and analytical instrument qualification will be important topics presented during ECA's Education Course "Analytical Instrument Qualification" from 20-22 February 2013 in Barcelona, Spain.
More details about these two USP General Chapters <41< and <1251> can be found in the online edition of the PF.