Recent experience within the last two weeks in the US suggests that surveyors acting on behalf of Dow Chemicals, when shipping Caustic Soda (50%) solution out of Point Comfort and Freeport,, Texas, are applying very strict standards of tank cleanliness and are frequently rejecting vessel's tanks in order to ship product at a quality higher than declared to ship's interests at the time of fixture.
This practice has resulted in several disputes with ships incurring extra cleaning costs, delay and in one case, cancellation of charter.
Products to be shipped from these supply ports were described as 'membrane', 'regular' and 'purified' caustic. All of these product descriptions are, in fact, chemically very similar and require no extra standard of tank preparation than would caustic soda available from elsewhere in the world.
a) In the case of epoxy coated tanks Owners should accurately declare the extent of coating break-down (rust) to charterers/shippers at the fixture stage and obtain an indication from cargo interests that cargo tank condition is satisfactory for the prospective shipment. In general coatings with break-down greater that 2% overall will be unacceptable to Dow but the standard required may well be less than this for those cargoes with the most stringent iron content specification. For these cargoes shippers surveyors will be looking for near perfect coatings with minimal defects.
b) If previous cargo was residual in nature or if cargo tanks are stained in any way, a thorough chemical wash is suggested, as Dow's surveyors will not tolerate the presence of even very minor traces of same. Shadow area residues/staining are also not acceptable even when such areas are a very small percentage of tank surface area. Caution is advised if vessel's tanks fall into the above general description as extra time/cost may have to be budgeted to reach the required standard of cleanliness
For further information contact :
Oil & Chemical Dept,
CWA Consultants Ltd.
Tel +44 171 245 6855
Fax +44 171 235 8192