At the 46th session of IMO's Marine Environment Protection Committee
(MEPC46) held from 23 April to 27 April 2001, amendments were made to the MARPOL convention as one of the countermeasures after the ERIKA accident. Present phasing out scheme of existing single hull tankers is further accelerated as given hereunder.

1 New Phasing out schedule in accordance with new MARPOL Regulation I/13G
Under new scheme given in the table attached, tankers are categorised as follows:
(a) "Category 1 oil tanker" means an oil tanker of 20,000 tons deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tons deadweight and above carrying oil other than the above, which does not comply with the requirements for new oil tankers as defined in regulation 1(26) of MARPOL Convention;
(b) "Category 2 oil tanker" means an oil tanker of 20,000 tons deadweight and above carrying crude oil, fuel oil, heavy diesel oil or lubricating oil as cargo, and of 30,000 tons deadweight and above carrying oil other than the above, which complies with the requirements for new oil tankers as defined in regulation 1(26) of MARPOL Convention;
(c) "Category 3 oil tanker" means an oil tanker of 5,000 tons deadweight and above but less than that specified in subparagraph (a) or (b) of this paragraph.
The phase our scheme for these tankers is re-developed as shown in the table below. Special attentions are to be made to the following points with regard to category 2 tankers and category 3 tankers:
(1) They are to be completely phased out in 2015, however, tankers with double bottoms or double side skins which may not comply with MARPOL Reg I/13F are allowed to operate until they reach 25 years of age by discretion of respective flag Administration, subject to the notification to be made to IMO;
(2) Other Category 2 tankers and Category 3 tankers which complying with Protective Location (PL) arrangements of ballast tanks or complying with Hydro-static Balance Loading (HBL) are allowed to operate until 2017 or until when the ship reaches 25 years, whichever the earlier, depending on the discretion of flag Administrations, subject to the notification to be made to IMO.
(3) Notwithstanding the measures given in (1) and (2) above, port States may reject entry of tankers in their jurisdiction to which the these measure are applied to.
In any case, for Category 1 oil tankers operating beyond 2005, and Category 2 oil tankers operating beyond 2010 are required to comply with CAS (Condition Assessment Scheme) given hereunder. However, accepting CAS is up to the discretion of each respective flag Administration. There could be a flag Administration which will not accept CAS for extending operational life. Such Administration are to inform IMO of its decision on this matter.