Carriage of the chemicals in bulk is enclosed by the regulations in SOLAS Chapter VII – Carriage of the dangerous goods & MARPOL Annex II – Regulations for the Control of Pollution by the Noxious Liquid Substances in the Bulk. Both the Conventions demand chemical tankers those are built after 1st July 1986 to follow with the International Code for the Construction & Equipment of Ships carrying Dangerous Chemicals in Bulk (IBC Code).
The IBC Code came up with an international standard for the safe carriage in bulk by sea of dangerous chemicals & noxious liquid substances listed in chapter 17 of the Code. To decrease the risks for the ships, their crews & the environment, the Code advises the design & construction standards of the ships & the equipment they should carry, with regard to the character of the products involved. In December 1985, by resolution MEPC.19(22), the Code was broaden to cover marine pollution aspects which applies to ships built after 1st July 1986.
In October 2004, IMO accepted revised MARPOL Annex II Regulations for the control of pollution by the noxious liquid substances in bulk. This comprise a 4 category categorization system for noxious & liquid substances & it enforced on 1st Jan. 2007.
Subsequent modification to the International Bulk Chemical Code (IBC Code) were also accepted in October 2004, give back the modification to MARPOL Annex II. The modification includes correction to the grouping of certain products associated to their properties as potential marine pollutants as well as revisions to ship type & carriage requirements following their assessment by the assessment of Hazardous Substances Working Group.
Ships concerning to the Code will be produced to one of the following standards:
- A type 1 ship is a chemical tanker considered to transport chapter 17 products with very extreme environmental & safety dangers which need maximum precautionary actions to prevent an escape of such cargo.
- A type 2 ship is a chemical tanker considered to transport chapter 17 products with extreme environmental & safety dangers which need significant precautionary actions to prevent an escape of such cargo.
- A type 3 ship is a chemical tanker considered to transport chapter 17 products with extreme environmental & safety dangers which need average degree of containing capacity to increase the survival ability in a damaged condition.
Thus, a type 1 ship is a chemical tanker considered for the transportation of products considered to present the maximum overall danger & type 2 & type 3 for products of lesser dangers. So, a type 1 ship will survive the most severe damage & its cargo tanks will be situated at the maximum advised distance inboard from the shell plating.
Code for Construction Equipment of the Ships Carrying Dangerous Chemicals in Bulk (BCH Code)
Under regulation 11 of Annex II to MARPOL 73/78, chemical tankers built before 1 July 1986 should follow with the conditions of the Code for the Construction & Equipment of Ships Carrying Dangerous Chemicals in Bulk (BCH Code) the precursor of the IBC Code. The BCH Code remains as a guidance under the 1974 SOLAS Convention.