1 The Marine Environment Protection Committee,
                           at its fifty-eighth session (6 to 10 October 2008), adopted, by resolutions MEPC.176(58) and MEPC.177(58), the revised MARPOL Annex
                           VI and the NOx Technical Code 2008.
                           
                        
                        
                        
                      
                     
                     
                     
                        
                        
                         
                           2 The purpose of the NOx Technical
                           Code 2008 is to provide mandatory procedures for the certification,
                           testing, and measurement procedures for the standards set forth in
                           regulation 13 of the revised MARPOL Annex VI. These procedures will
                           enable engine manufacturers, shipowners, and Administrations comply
                           with regulation 13 of the revised Annex VI.
                           
                        
                        
                        
                      
                     
                     
                     
                        
                        
                         
                           3 On 1 July 2010, the NOx Technical
                           Code 2008 is expected to enter into force. However, beyond this date,
                           there are circumstances applicable to Tier I certification and amendments
                           where the NOxTechnical Code (1997) should be applied.
                           
                        
                        
                        
                      
                     
                     
                     
                        
                        
                         
                           4 In order to assist Administrations regarding
                           the application of the appropriate version of the NOx Technical
                           Code with respect to Tier I engine certification and amendments, for
                           engines installed on ships constructed before 1 January 2011, MEPC
                           59 (13 to 17 July 2009) considered and approved a flow chart providing
                           guidance, which is attached as an annex to this circular and is recommended
                           to be considered by Administrations.