300 



Addendum to Footnote'* 



The delegations of Denmark, Fiance, Federal Republic of Germany, Nether- 

 lands, Norway, Sweden and the United Kingdom are of the opinion that the 

 treatment proposed for the black oil (i)ersistent) group in Regulation 9 is not 

 appropriate for the white oil (non-persistent) group, the actual hazards of which 

 have not been adequately evaluated. 



(a) Black oils because of their persistence can travel on the surface of the 

 water for some distance under the action of winds and currents. The controls of 

 effluents in Regulation (60 litres i>er mile) ensure that crude oil tank washing 

 and other discharges do not pollute and the 50 mile requirement for these efflu- 

 ents provides a very large margin for the protection of shallow areas and beaches 

 in the area if the stipulated discharge criteria are inadvertently exceeded. 



(b) White oils even when discharged in substantial quantity in the open sea 

 have very short lived persistence as evidenced by the recent tests by the United 

 Kingdom off Milford Haven (PCMP/4/33). These tests involved the discharge 

 of gas oil and gasoline at rates and concentrations which would never be reached 

 in operational practice (the rates were as high as 50m^ and 30m' per mile re- 

 spectively). The heavy gas oil, the least volatile of the white oil group, produced 

 only trace indications 2iA hours after the discharge when only a small quantity 

 (between 2% and 12% of the original discharge) remaine<l in the sea at a con- 

 centration below 0.5 ppm in tlie sub-surface layers. A similar test with gasoline, 

 with its higher evaporative rate, produced no discernible traces either on the 

 surface or in the water coliunn in 60 minutes from the discharge, the discharge, 

 in this time, having vaporised completely. The residues in the water are con- 

 sidered to be no more harmful probably than sulistances in Annex II. Category C. 



(c) Retention procedures appropriate for the carriage of crude oils are not 

 applicable for white oils since it is inadvisable to mix retained product residues 

 with subsequent cargoes. 



Nevertheless it is believed that some sensible control should be imposed upon 

 white oil discharge to the sea in order to prevent malpractice and to ensure that 

 no pollution of the sea is produced when such discharge takes place by regulating 

 the discharge in a way which will aid its natural evaimration and dispersal. 



The basis on which controls wiiich the delegations consider wou'd produce no 

 pollution of the sea could, it is suggested, be produced by developing the following 

 concepts : 



(1) Ships on final discharge of white oil cargoes shall strip the cargo tanks and 

 drain lines ashore to the maximum extent practicalile. 



(2) Lines shall not be flushed direct to sea but flushed back to appropriate 

 cargo tanks. 



(3) Discharge to the sea of line flushings and/or tank wash water from cargo 

 tanks shall only commence when there is water in the tank bottom of at least 

 [Moo] of the tank volume. 



(4) Such discharge to the sea should be at the minimum rate practicable by 

 the ship's pumping arrangements. 



(5) Such discharge shall only be made when the tanker is at least [ ] 



miles from the nearest land, is in a given depth of water, and is proceeding en 

 route at a specified minimum speed. 



A preliminary division of the oils listed in Appendix to this Annex into Class I 

 (persistent or black oils) and Class II (non-persistent or white oils) is attached 

 for further consideration. 



The delegations mentioned consider that the above procedure is more consistent 

 with the proi)Osals in Annex II for generally similar but. in some cast^, more 

 toxic sulKStances than the petroleum products referred to here. If there is doubt 

 as to the adequacy of the above procedure it is suggested that a representative 

 selection of white oil products be put forw^ard to GESAMP for expert assessment 

 of the comparative hazards. 



Appendix 



list of oils in category i 



Crude oils: Reconstituted crude. 



Diesel Fuels: Marine diesel oils. 



Residual Fuel Oils: No. 4 fuel. No. 5 fuel. No. 6 fuel, and Bunker "C". 



Asphalts: Coatings, and road oils. 



Lubricating Oils: Automotive, industrial, cutting oils, and transformer oils. 



Lubricating Oil Blend Stocks: Bright stocks, lubricating oil distillates, solvent 



1* See footnote p. 273. 



