THE LOSS OF THE CHEMICAL TANKER IEVOLI SUN IN THE ENGLISH CHANNEL, OCTOBER 2000
by Robin Law 1, Carole Kelly 1, Peter Matthiessen 1 and John Aldridge 2
Table 1: Chemical, toxicological and ecotoxicological properties of styrene.
Start Point
Introduction
In October 2000, the chemical tanker Ievoli Sun travelling from Southampton to Genoa began taking
in water due to bad weather in the English Channel. She was taken in tow by a French tug, but sank
24 hours later 11 miles northwest of Alderney.
Ths ship’s cargo consisted of:
4,000 t styrene
1,000 t iso-propyl alcohol (IPA)
1,000 t methyl ethyl ketone (MEK)
bunkers of 180 t intermediate fuel oil (IFO180) and 53 t of gasoil.
Under a bilateral agreement the French authorities took primary responsibility for salvage, although
the vessel sank in UK waters. In such instances, CEFAS provides advice to DEFRA and the FSA on
the behaviour, fate and effects of oils and chemicals, and their potential impact on both fish and
shellfish stocks and human consumers.
•
•
•
•
35km
CAS registry number
Specific gravity
Boiling point
Solubility in water
Vapour pressure
Volatisation t1/2
Ozonolysis/hydrolysis t1/2
Biodegradability in lake and groundwater
Log K OW
Bioaccumulation factor
Accute toxicity to aquatic organisms
(mainly freshwater data)
Predicted chronic no-effect
concentration for aquatic organisms
Oral LD50 in the mouse
WHO No-observed-advers effect
level (NOAEL)
Tainting threshold in water for fish
Taste threshold
Odour threshold
‘Tentative’ EQS values (UK):
31/10/2000
9H30
ENGLISH CHANNEL
Vessel sank
ALDERNEY
30/10/2000
8H00
30/10/2000
22H00
Cap
de la Hague
Cherbourg
GUERNSEY
30/10/2000
16H47
Start of tow
JERSEY
The English Channel, showing where the Ievoli Sun
was abandoned on the morning of 30 October,
where she was taken under tow by the evening of
the same day, and where she sank on the morning
of 31 October 2000.
Toxicity of chemicals - behaviour
IPA and MEK are volatile solvents, but are miscible and will become rapidly dispersed and diluted
within the water column. Styrene is also volatile but is almost insoluble in water, and has a lower
density than seawater. After release styrene will rapidly rise to the sea surface and evaporate. All
three chemicals are of low to moderate toxicity to aquatic life and are not persistent, with a very
low bio-accumulation potential in marine animals.
Styrene, however, can taint fish and shellfish, and is also considered a possible human carcinogen.
There is some evidence that it may have endocrine disrupting properties. The chemical and
ecotoxicological properties of Styrene are summarised in Table 1.
Bunker fuels: gasoil is toxic to marine life, but will rapidly disperse in seawater and/or evaporate
from the sea surface. IFO180 is more persistent and would form a surface slick but should be
100-42-5
0.909
145-146°C
> 300 mgl-1 at 20°C
4.5 mm Hg at 20°C
1-14 hours
3.5-9 hours
t1/2 in water > 20-30 days
2.95 - 3.05
Low, 13-70 in fish
2 to 726 mgl-1 depending upon species
41 µgl-1 (hardly any data)
316 mg/kg body weight-1
7.7 mg/kg body weight
250 µgl-1 in yellow perch
94 µgl-1
3.2-2600 µgl-1 in water
Annual average 50 µgl-1
Maximum allowable concentation 500 µgl-1
Contamination of shellfish
Cargo removal from ship
Crabs recovered from pots within the 3 mile navigational exclusion zone around the Ievoli Sun were
recovered and analysed by CEFAS and IFREMER. Styrene was confirmed to be present in their tissues,
at concentrations from 7 to 500 µg kg-1 wet weight. Such concentrations pose a negligible risk to
human consumers. Also, as styrene is rapidly eliminated from tissues, these concentrations
represented “worst-case” conditions, and further tainting of fish and shellfish beyond the exclusion
zone was unlikely.
The cargo was removed from the ship in April-June 2001. The styrene and IFO180 were recovered,
and the MEK and IPA released to the sea in a controlled manner as they presented little threat.
DATA01#1941 RT: 5.08 AV: 1 SB: 870 4.06-4.95, 5.37-6.58 NL: 5.26E4
T: + c Full ms [ 30.00-350.00]
104.1
78.1
100
95
90
85
80
75
70
65
60
55
50
50.0
50.0
103.1
77.1
45
40
51.0
35
49.8
49.8
50.0
30
25
20
15
49.6
49.4
(a)
0
30
40
50
56.1
60
102.2
79.1
73.1
70
105.1
81.1 85.1 89.1
80
90
96.2 97.8
100
110.2
117.1
110
49.4
49.2
49.0
49.0
-2.8
-2.6
-2.4
-2.2
LONGITUDE
-2.0
-1.8
-1.6
-3.0
(b)
GC/MS spectra confirming the identity of styrene in one of the three
samples of crabs taken from within the navigational exclusion zone.
Wreck investigation
-2.8
-2.6
-2.4
-2.2
LONGITUDE
-2.0
-1.8
-1.6
Initial assessment - modelling slick movement
Modelling showed that the combination of winds and tide would keep surface slicks to the north
of Alderney, and that there was no immediate likelihood of them approaching land. Our initial
assessment was that the spill posed no major threat to either marine life or human consumers.
Although toxicity and contamination may be seen within the immediate vicinity of the wreck,
it was likely to be both very localised and short-lived.
Styrene leakage from the vessel (identified by overflights) consisted of small surface slicks of
approximately 1 t, which rapidly evaporated from the sea surface. Northerly winds resulted in
chemical smells being reported on Alderney and a monitoring station was set up on the island.
On-site monitoring was carried out by the counter-pollution vessel Neuwerk. About 1,000 t of
styrene was believed lost during the incident.
2
38.0 41.0
64.1
m/z
Predictive computer modelling of the movement of styrene on the sea surface, generated by an
oceanographic particle-tracking model using real wind and tide conditions.
(a) 0600h on 30 October; (b) 1800h on 30 October.
1
31.1
49.0
74.1
63.1
62.1
52.1
39.0
5
49.2
-3.0
32.0
10
LATITUDE
LATITUDE
49.6
Remotely Operated Vehicles (ROVs) were used to survey the vessel on the seabed. Following these
surveys, the leaks observed in the vessel’s hull were sealed, and salvage operations awaited better
weather in spring 2001.
Conclusions
1,000 t of styrene were lost from the vessel, leading to slight contamination of shellfish in the
• Over
immediate area.
t styrene and IFO180 were recovered from the wreck on the seabed, and the remaining cargo
• 3,000
was released in a controlled manner.
assessments of the likely impact of the incident made were fully borne out by subsequent
• Initial
events.
Acknowledgements
Work carried out by CEFAS following oil and chemical incidents at sea is funded by the Department
for Environment, Food and Rural Affairs and the Food Standards Agency. All photographs are
reproduced with the permission of the Ministère de l’Equipment, des Transports et du Logement.
Further information
www.equipement.gouv.fr/ievoli.sun
The Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Burnham Laboratory, Remembrance Avenue, Burnham on Crouch, Essex CM0 8HA, UK.
The Centre for Environment, Fisheries and Aquaculture Science (CEFAS), Lowestoft Laboratory, Lowestoft, Suffolk NR33 OHT, UK.
http://www.cefas.co.uk
© Crown Copyright 2001