The International Maritime Organisation (IMO) Working Group on the Evaluation of Safety and Pollution Hazards of Chemicals (ESPH 19), meeting at IMO Headquarters from 21 to 25 October, has agreed to classify high-viscosity PIB (Polyisobutylene) as category X for carriage by ship, thereby prohibiting the discharge of cargo residues into the sea.
Previously, PIB was classified as category Y material but there was no differentiation between high or low viscosity grades. Low-viscosity PIB will remain as a category Y product.
PIB is an oil additive, often used to improve the performance of lubricating oil, and is found in products ranging from adhesives to sealants and chewing gum. It is very hazardous to seabirds, who dive underwater to feed and become covered in the sticky substance. This leads to immobilisation, hyperthermia, starvation and eventually death.
The categorization and carriage requirements for high-viscosity PIB will be included in the annual MEPC.2/Circular on the Provisional categorization of liquid substances, usually issued by the IMO on 17 December each year and will be put forward for inclusion in the next edition of the International Code for the Construction and Equipment of Ships carrying Dangerous Chemicals in Bulk (IBC Code) which 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 put forward on an annual basis so the next amendments would be considered during 2014, for inclusion in the IBC Code with an effective implementation date of 1 July 2016.
Category X under the International Convention for Prevention of Pollution from Ships Annex II Regulations for the control of pollution by noxious liquid substances in bulk includes noxious liquid substances which, if discharged into the sea from tank cleaning or deballasting operations, are deemed to present a major hazard to either marine resources or human health and, therefore, justify the prohibition of the discharge into the marine environment.
For substances under category X, a tank from which a substance in Category X has been unloaded, must be prewashed before the ship leaves the port of unloading. The resulting residues must be discharged to a reception facility until the concentration of the substance in the effluent is at or below 0.1% by weight.