23 October 2013: The International Maritime Organization (IMO) announced an agreement to classify high-viscosity Polyisobutylene (PIB) as Category X for carriage by ships, prohibiting the discharge of cargo residues into the sea. The agreement was reached at the 19th meeting of IMO’s Working Group on the Evaluation of Safety and Pollution Hazards of Chemicals (ESPH 19), which convened from 21-25 October 2013, in London, UK.

According to the IMO, chemicals in Category X are deemed to present a major hazard to either marine resources or human health if discharged into the sea from tank cleaning or deballasting operations. Therefore, the discharge of such substances is prohibited.

The IMO says the PIB categorization and carriage requirements for high-viscosity PIB will be proposed for inclusion in the next edition of the International Code for the Construction and Equipment of Ships carrying Dangerous Chemicals in Bulk (IBC Code). The IBC Code lists chemicals and their hazards and gives both the ship type required to carry that product as well as the environmental hazard rating. Amendments to the IBC Code are considered annually, and will likely be considered next in 2014, bringing the PIB classification into effect in July 2016. [IMO Press Release]