Bahamas
1998
Brazil
Rest of the world
Bulk
HNS Spilt
Sulphuric acid 95%Liquid
H2SO4
Amount Spilt (T)1700
CAS Number7664-93-9
-
D
Physical Behaviour (SEBC code)
-
Y
Pollution Category (MARPOL Annex 2)
-
8
Class according to IMDG code
-
-
Subsidiary Risk Class according to IMDG code
-
Classification as Marine Pollutant
-
ii, iii
HNS Classification (2010 HNS Convention)
Fate and weathering facts observed/reported
Internal damage to the ship required immediate release of the acid into the Rio Grande Channel. This discharge was controlled, with release to the environment only during ebb tide at a minimum discharge velocity of 20 cm.s–1, and with continuous monitoring of the water pH in the channel. Part of the cargo was recovered (12,000 T). With regard to the release of heavy metals due to the corrosion of the ship's structure, various analysis were carried out and indicated that the concentration levels of the mixture on board, except iron compounds - FeS and Fe (OH)3 - remained within the limits accepted by the Brazilian regulations. The ship was then towed to international waters. Chemical monitoring of the pH showed some impact on the environment with direct and indirect reactivation of toxic metals absorbed in port sediment. The soft bottom macrobenthic invertebrate assemblage recovered six months after the sulphuric acid spill.