Polyisobutylene to be classified as category X in MARPOL Annex II
IMO’s 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.
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 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.
MARPOL Annex II lists four categories for noxious liquid substances carried in bulk:
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.
NGOS have called for review of legal discharge of PIB, asPolyisobutene had been suspected to cause the death of thousands of seabirds.
Polyisobutene (PIB) is a man-made substance (or group of substances) used, for example, in the manufacture of chewing gum, adhesive tape and sealants. In its raw state, it is generally colourless or light yellow, odourless, tasteless and cannot easily be identified. It is also not biodegradable. Global consumption of liquid PIB is forecast to increase by around 40% by 2017 to 1.2 million tonnes per year, most of which is transported by ship.
PIB is a hydrophobic substance, so on contact with water it coalesces into a waxy, glue-like formation, generally floating at or just underneath the surface. As such it is extremely hazardous to a range of seabird species which dive to find food (auks, such as guillemots, razorbills and puffins, as well as gannets, fulmars and shags are particularly vulnerable). The longer-term impacts of PIB releases on marine ecosystems are not well understood.
Polyisobutene (PIB) has been identified as the substance covering large numbers of seabirds that have washed up on beaches in Devon, Cornwall and Dorset.According to wildlife charities, hundreds of sea birds have been killed and many more injuredafter the PIB covered the birds became glue-like in seawater, preventing them fromswimming, flying or catching prey.
The ban has been also recommended by the Maritime and Coastguard Agency (MCA).
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