Unified Interpretations


Unified Interpretations are adopted resolutions on matters arising from implementing the requirements of IMO Conventions or Recommendations. Such adopted resolutions can involve uniform interpretations of Convention Regulations or IMO Resolutions on those matters which in the Convention are left to the satisfaction of the Administration or vaguely worded.

Interpretations are circulated to Administrations concerned or are sent to IMO for information, as appropriate.


  1. IACS, as an international Non-Governmental Organization having observer status at IMO, works in co-operation with IMO in order to endeavour that regulations developed at IMO are clear, unambiguous and can easily be applied without the need of interpretations.
  2. However, interpretations may still be needed in cases where IMO regulations contain only functional requirements, allow alternative solutions to prescriptive requirements, are left to the satisfaction of Administrations or are generally or vaguely worded.
  3. The following Unified Interpretations (UIs) have been developed by IACS to assist the unified implementation of IMO regulations falling in the above-mentioned cases. It should be noted that the development of IACS Unified Interpretations (UIs) is not aiming at introducing additional requirements but at achieving uniform application of IMO regulations.
  4. IACS UIs are to be applied by IACS Societies to ships whose flag Administrations have not issued definite instructions on the interpretation of the IMO regulations concerned, in the course of statutory certification on behalf of those flag Administrations.

The technical backgrounds (development histories) of Unified Interpretations since 2004 can be found by following this link.

A list of the IACS working groups responsible for each Unified Interpretation may be found here.

UI SC73 Rev2 CLN

UI SC73 Fire protection of weather decks Reg. II-2/20.4 and 20.6) - Rev.2 Nov 2005

UI SC74 Deleted

UI SC74 Fire protection arrangements in cargo spaces including special category spaces Deleted in Nov 2005 because of SOLAS 2000 Amendments

UI SC75 Rev1 CLN

UI SC75 Fire protection arrangements in cargo spaces (Reg. II-2/ - Rev.1 Nov 2005

UI SC76 New

UI SC76 Engine bearing temperature monitors (Chapter II-1, Regulation 47.2 [1981]) 

UI SC77 Deleted

UI SC77 Cargo tanks overflow control system use of spill valves Deleted in Nov 2005 because of SOLAS 2000 Amendments.

UI SC78 Deleted

UI SC78 Fire safety measures for tankers Deleted in Nov 2005 because of SOLAS 2000 Amendments

UI SC79 Rev4 CLN

UI SC79 Certified Safe Type Electrical Equipment for Ships Carrying Dangerous Goods (Chapter II-2, Regulation 19.3.2)-  Rev.4 October 2015 Clean

UI SC80 Deleted

UI SC80 Fire-Extinguishing Arrangement for Paint Lockers Deleted in Nov 2005 because of SOLAS 2000 Amendments.

UI SC81 Rev1 CLN

UI SC81 Drainage of enclosed spaces situated on the bulkhead deck (Chapter II-1, Regulation 35-, Res. MSC.194(80)) - Rev.1 February 2010 Clean

UI SC82 Deleted

UI SC82 Protection against noise (Chapter II-1, Regulation 36) Deleted 1 July 2014.

UI SC83 New

UI SXC83 Continuity of the Supply when Transformers Constitutes an Essential Part of the Electrical Supply System (Chapter II-1, Regulation 41.1.5) 

UI SC84 Rev2 CLN

UI SC84 Purpose Built Container Space (Reg. II-2/ - Rev.2 Nov 2005

UI SC85 Rev1 CLN

UI SC85 Ro-Ro Space (Reg. II-2/ - Rev.1 Nov 2005

UI SC86 Rev1 CLN

UI SC86 Weather Decks (Reg. II-2/19, Table 19.1) - Rev.1 Nov 2005

UI SC87 Rev1 CLN

UI SC87 Certification of Carriage of Solid Dangerous Bulk Cargoes (Reg. II-2/19.3 and 19.4) - Rev.1 Nov 2005

UI SC88 Deleted

UI SC88 Fire Water Supply Capacity Deleted in Nov 2005 because of SOLAS 2000 Amendments.

UI SC89 Rev3 CLN

UI SC89 Ventilation of Cargo Spaces (Reg. II-2/19.3.4) 0 Rev3 February 2011 Clean

UI SC90 Rev1 CLN

UI SC90 Bilge Drainage (Reg. II-2/19.3.5) - Rev.1 Nov 2005

UI SC91 Rev1 CLN

UI SC91 Personal Protection - Protective Clothing (Reg. II-2/ - Rev.1 Dec 2005

UI SC92 Rev1 CLN

UI SC92 Personal Protection - Self-Contained Breathing Apparatus (Reg. II-2/ - Rev.1 Nov 2005

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