295
1 INTRODUCTION
Transportandhandlingof hazardous chemicals and
chemical products has considerably increased over
the last 20 years, thus increasing the risk of major
pollutionaccidents.Worldwide,about2000chemicals
are transported by sea either in bulk or packaged
form.Onlyfewhundredchemicalsaretransportedin
bulk but these ma
ke up most of the volume of the
chemical seaborne trade (Purnell 2009). Chemical
releasesarethoughttobepotentiallymorehazardous
thanoil.Astomarinespills,chemicalsmayhaveboth
acuteandlongterm environmental effects,and may
notbeaseasilyrecoverableasoilspills.Inaddition,
public safety risks are more severe in chemical
releases(EMSA2007).
TheBalt
icSeaisoneofthebusiestsearoutesinthe
world15%oftheworld’scargomovesinit.In2010,
the international liquid bulk transports in the Baltic
Seaportscontainedaround 290milliontonnesofoil
andoilproducts,atleast 11 milliontonnesof liquid
chemicals, and 4 million tonnes of other liquid bulk
(Holma et al. 2011; Posti & Häkkinen 2012). In
addition,chemicalsaretra
nsportedinpackagedform,
but tonnes are not studied. Navigation in the Baltic
Review of Maritime Accidents Involving Chemicals
Special Focus on the Baltic Sea
J
.M.Häkkinen&A.I.Posti
UniversityofTurkuCentreforMaritimeStudies,Kotka,Finland
ABSTRACT:Transportandhandlingofhazardouschemicals andchemicalproductsaroundtheworld’s waters
andportshaveconsiderablyincreasedoverthelast20years.Thus,theriskofmajorpollutionaccidentshasalso
increased.Pastincidents/accidentsare,whenreportedindetail,firsthandsourcesofinformat
iononwhatmay
happen again. This paper provides an overview of the past tanker accidents in the Baltic Sea and chemical
relatedaccidentsinseasworldwide.Theaimistofindoutwhatcanbelearnedfrompastaccidents,especially
fromtheenvironmentalpointofview.Thestudyiscarriedoutasalit
eraturereviewandasastatisticalreview.
Thestudyrevealedthattheriskofachemicalaccidentishighestinseaswherethehighesttonnesofchemicals
are transported, the density of maritime traffic is highest and, of course, in the shipshore interface where
unloading/
loadingtakesplace.Incidentsinvolvingchemicalspillsarestatisticallymuchlesslikelytooccurthan
oilspills.However,chemicalcargoescanbemoredangeroustohumansandpropertybecausechemicalscanbe
morecombustible,poisonous,irritatingandreactive.Themostimportantdifferencebetweenachemicalandan
oilspillmayberelatedtoresponseact
ions.Incaseofachemicalaccident,theairqualityortheriskofexplosion
should be more carefully evaluated before any response actions are taken. In case of chemical spills, the
responseismorelimitedincomparisontooil.Actually,verylittleisknownabouttheact
ualmarinepollution
effectofmost ofhighlytransportedsubstances. Fromtheenvironmentalpointofview,thepreviousstudies
havehighlightedaccidents inwhichpesticideswerereleasedtowater,butalsosubstancesconsideredasnon
pollutants(vegetableoils)seemtohaveanegativeeffectonbiotainthewaterenvironment.
http://www.transnav.eu
the International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 8
Number 2
June 2014
DOI:10.12716/1001.08.02.16
296
Sea is challenging due to the relative shallowness,
narrownavigationroutes,andicecoverofthesea.Oil
and chemicals are a serious threat to the highly
sensitive Baltic Sea ecosystems. Recently, both the
numberandthevolumeofthetransportedcargohave
increased significantly in the Baltic Sea (HELCOM
2009), concomitantly raising the spill/ship collision
riskintheBalticSeaareas(Hänninenetal.2012).The
resultsofpreviousstudies(EMSA2010,Hänninen&
Rytkönen2006,Bogalecka&Popek2008,Mullaietal.
2009, Suominen & Suhonen 2007) indicate that both
thespillrisksandchemicalincidentsarenot
aswell
definedthanthoseconcerningoils.Theexpectedspill
frequencyandspillvolumescausedbyshipchemical
tankercollisionsintheGulfofFinland(GoF)collision
probabilityaremuchlessincaseofchemicaltankers
than in case of oil tankers (Sormunen et al. 2011,
Sormunenetal.2014).Nevertheless,
amongthewide
rangeofchemicalstransported,thepotencytocause
environmentaldamagecannotbeoverlooked.
At their best studies about historical chemical
accidents may offer valuable lessons about the
reasonsleadingto the accident, itsenvironmentalor
healthrelated consequences or even the costs of the
accident. First studies
concerning past maritime or
portrelated HNS accidents were already made two
decades ago (Rømer et al. 1993; 1995; Cristou 1999).
More recently, many excellent papers and reports
concerning maritime accidents have been written,
concentrating mainly on the probability and
environmental consequences of accidents (e.g.
Marchand 2002; Wern 2002) Response to
harmful
substances spilled at sea (Drogou et al. 2005; EMSA
2007; Mamaca et al. 2009). Oil accidents have been
studied more than other HNS accidents, but this is
simply because of the higher incident numbers and
larger spills (Burgherr 2007). One of the most
importantissuesstudiedisthedifference
inresponse
actions in the case of oil and chemical accidents
(Marchand2002;EMSA2007;Purnell2009).
The study and analysis of past accidents with
consequencestotheenvironmentandhumanscanbe
a source of valuable information and teach us
significant lessons in order for us to prevent future
shipping
accidents and chemical incidents. The
purpose of this study is to provide a review of the
pasttankeraccidentsintheBalticSea,andchemical
related accidents in seas worldwide, thus aiming at
finding out what can be learned from these past
accidents, including e.g. occurrence, causes, general
rules and
particular patterns for the accidents. The
study focuses mainly on chemicals transported in
liquefied form, but chemical accidents involving
substances in packaged form are also studied.
Conventionaloilandoilproductsare observed only
on a general level. The special scope inthe study is
putonenvironmentalimpactassessment.
2
MATERIALSANDMETHODS
The study was carried out in two stages. First, a
literature review on maritime accidents involving
hazardous substances and especially chemicals was
made to find out what kind of studies have
previouslybeenconductedonthetopic,andwhatare
the main results of these studies. Both
scientific
articlesandresearchreportsweretakenintoaccount.
Thestudiesweremainlysearchedbyusingnumerous
electronicarticledatabasesandawebsearchengine.
Second, a statistical review on maritime tanker
relatedaccidentsinthe BalticSeawascarriedoutto
findouttheamountandtypesoftankeraccidents
that
haveoccurredintheBalticSeainrecentyears,andto
examine what kind of pollution these accidents
caused and have caused since. All types of tankers
(e.g.oiltankers,oilproducttankers,chemicaltankers,
chemical product tankers and gas tankers) were
included in the review. An overview of
the tanker
accidents in the Baltic Sea was made by using
maritime accident reports provided by the Helsinki
Commission (HELCOM) and by the European
Maritime Safety Agency (EMSA). More detailed
information about maritime accidents involving a
tanker was searched using maritime accident
databases and reports provided by the authorities
and/or other
actors responsible for collecting
maritime accident data in each Baltic Sea country.
Moredetailedmaritimeaccidentinvestigationreports
on accidents were found from Denmark, Finland,
Germany, Latvia and Sweden; basic information
about accidents was found from Estonia and
Lithuania;andnomaritimeaccidentdatawasfound
fromPolandandRussia.
3 MARITIMEACCIDENTSINVOLVING
CHEMICALS
Therearefewmorerecentimpactassessmentstudies
for chemical spills in the scientific literature in
comparison to those for oil spills. Recently,there
have been some good papers and accident analyses
concerning chemicals and other hazardous materials
(conventional oil omitted), such as Cedre and
Transport
Canada 2012, EMSA 2007, HASREP 2005,
Mamacaetal. 2009, Marchand 2002 and Wern 2002.
In addition, the Centre of Documentation, Research
and Experimentation on Accidental Water Pollution
(Cedre) collect informationabout shipping accidents
involving HNS for an electric database by using
various data sources (Cedre 2012). None of those
aforementioned sources are, or even try to be,
exhaustive listings of all accidents involving
chemicals and other hazardous materials, but they
have gathered examples of wellknown accidents
withsomequalityinformation.Bycompilingaccident
data from aforementioned sources, 67 famous
tanker/bulk carrier accidents involving chemicals
and/or other hazardous materials were
detected.
These accidents frequently involved chemicals or
chemical groups like acids, gases, vegetable oils,
phenol, ammonia, caustic soda and acrylonitrile.
Using the same information sources, 46 accidents
involving packaged chemicals or other hazardous
materials were listed. In comparison to bulk
chemicals,itcanbeseenthatthevarietyofchemicals
involved in accidents is much higher in the case of
packagedchemicals.Inthissection,keyfindingsand
lessons to be learned from in relation to vessel
chemical accidents are discussed in more detail, the
analysisbeingbasedonoriginalkeystudies.
297
3.1 Overviewofmaritimechemicalaccidentsworldwide
One of the earliest scientific analyses of the past
maritimeaccidentswasmadebyRømeretal.(1993;
1995). Based on 151 marine accidents involving
dangerous goods, Rømer et al. (1993) calculated
accident frequencies for the different accident types
(collisions,groundings,fire/explosionsand
structural
damage). All types of accidents were rare, ranging
from 1 x 103 to 2 x 102. In their analysis, the
accidents involving oils were twice as frequent as
accidentsinvolvingchemicals.InRømeretal.(1995),
the consequences measured by the number of
fatalities from marine accidents
(n=1780) during the
transportof dangerous goods were investigated and
comparedwith those fromother modes of transport
(n=1001). Accidents concerning the marine transport
ofdangerous goodswerefoundtocomprisealarger
proportionofaccidentswithfatalitiesintherangeof
10–50 than other transport modes. Almost all
accidentswith
morethan40fatalitieswerecollisions
and accidents with more than 100 fatalities were
collisions between (oil)tankers and ferries.
Surprisingly, the cargo type, containment type,
geographicallocationortimeperiodhadnoeffectin
thisstudy(Rømeretal.1995).
Rømeretal.(1996)researched,onthebasisof1776
descriptions of water transport accidents involving
dangerous goods, the environmental problems
relatingtoreleasesofthiskind. Itwasfoundthatthe
most detailed descriptions of environmental
consequencesconcernedoil accidents,althoughmost
of the consequences were described as reversible
changes. It was shown that crude oil releases, on
average,are
approximatelyfivetimeslargerthanthe
releasesofoilproducts,andthatoilproductreleases
are approximately five times larger than those of
other chemicals. Only 2% of the 1776 accidents
described in the study contained information on
consequences to living organisms, and only 10%
contained any information on consequences
to
ecosystems. A relationship between the minimum
kilometres of shore polluted and the tonnes oil
released was found in oil accidents. Oil slicks were
shown to be five times their breadth in length.
Gravity scales used to describe and evaluate
environmental consequences were discussed in the
studyaswell.
Gunster et
al. (1993) studied petroleum and other
hazardouschemicalspillsinNewarkBay,USA,from
1982 to 1991. A record obtained from the United
StatesCoastGuard(USCG)included1453accidental
incidentsthathadresultedinthereleaseofmorethan
18 million US gallons of hazardous materials and
petroleum products
in the Newark Bay area. Most
accidents had occurred with fuel oils and gasoline.
The authors reviewed many environmental studies
andconcluded that with regards to the amountand
frequency of these spills, the elimination of entire
species and a reduction in biotic diversity have
typicallybeenobservedamongbenthiccommunities
aftermajorreleases.Manycompoundsarealsolong
livedintheenvironmentandtherebyposeachronic
threattoaquaticorganismslongaftertheacuteinitial
effectsofthespillhaveabated(Gunsteretal.1993).
Marchand(2002)presentedananalysisofchemical
incidents and accidents in the EU waters
and
elsewhere, and stated that 23 incidents had
information written down on related facts, such as
accident places and causes, chemical products
involved, response actions and environmental
impacts.Thestudycategorizedtheaccidentsintofive
groups according to how the substance involved
behaved after being spilled at sea: products as
packaged
form; dissolvers in bulk; floaters in bulk;
sinkers in bulk; and gases and evaporators in bulk.
Based on Marchand’s (2002) analysis, most of the
accidentshappenedinthetransi tphaseatsea,thatis,
while the vessel was moving. Only four accidents
happened in ports or in nearby zones. Most
of the
accidentshappenedwithbulkcarriers(62percentof
all the incidents), and less often with vessels
transportingchemicalsinpackagedform(38%).Bad
weather conditions and the resulting consequences
werethemaincauseoftheaccidents(in62percentof
all the cases). Marchand (2002) highlighted
several
issues concerning human health risks in the case of
maritimechemicalaccidents.Healsopointedoutthat
in most accident cases the risks affecting human
health come usually from reactive substances
(reactivitywithair,water orotherproducts)andtoxic
substances. The evaluation of the chemical risks can
be
verydifficultifashipiscarryingdiversechemicals
andsomeofthoseareunknownduring thefirsthours
aftertheaccident.Amorerecentstudy,Manacaetal.
(2009)weightedthesame chemicalrisksasMarchand
(2002).Certainsubstancessuchaschlorine,
epichlorohydrine, acrylonitrile, styrene, acids and
vinyl acetate are
transported in large quantities and
mayposeaveryseriousthreattohumanhealthbeing
highlyreactive,flammableandtoxic.BothMarchand
(2002) and Mamaca et al. (2009) pointed out that
consequences and hazards to the environment have
varied a lot, considering chemical tanker accidents.
Bothstudiesstatedthat,in
lightofaccidents,pesticide
productsareoneofthebiggestthreatsforthemarine
environment.Ifpesticides enterthemarine
environment, consequences for the nearshore biota,
and simultaneously for the people dependent on
these resources could be severe. On the other hand,
evensubstancesconsideredasnonpollutants,suchas
vegetable oils (in accidents like Lindenbank, Hawaii
1975;Kimya,UK1991;Allegra,France1997),canalso
have serious effects for marine species like birds,
musselsandmammals(Cedre2012,Marchand2002).
Bysurveying47ofthebestdocumentedmaritime
transportaccidentsinvolving chemicalsintheworld
from as early as
1947 to 2008, Mamaca et al. (2009)
gathered a clear overview of lessons to be learned.
Eventhoughthedatawastoonarrowforittobeused
inmakinganystatisticalfindings,thestudy presented
somegoodexamplesofmaritimechemicalaccidents.
32ofthoseaccidentsoccurredinEurope.The
listof
chemicals that were involved in the accidents more
than one time included sulphuric acid (3),
acrylonitrile (3), ammonium nitrate (2), and styrene
(2).Only10ofthe47accidentsoccurredinportsorin
nearbyzones.Moreover,66percentoftheaccidents
involved chemicals transported in bulk,
whereas 34
per cent involved hazardous materials in packaged
form.Primarycausesforthereviewedaccidents were
also studied. Impropermaneuver was most
frequentlythereasonfortheaccident(in22percent
ofallthecases),shipwreckcamesecond(20%),and
298
collision was third (13 %), closely followed by
groundingandfire(11%each).
Based on past accident analysis considering
packagedchemicals,Mamacaetal.(2009)pointedout
that,inlightofpackagedgoods,asaconsequenceof
high chemical diversity present on the vessel,
responders must know environmental fates
for
different chemicals individually as well as the
possible synergistic reactions between them. Even
though smaller volumes are transported, packaged
chemicals can also be extremely dangerous to
humans. This could be seen when fumes of
epichlorohydrine leaking from the damaged drums
ontheOostzee(Germany1989)seriouslyaffectedthe
ship´s
crewandcausedseveralcancercasesthatwere
diagnosedyearsafter(Mamacaetal.2009).However,
thesetypesofaccidentsinvolvingpackagedchemicals
have only a localized shortterm impact on marine
life. As to accidents caused by fire, there are
difficultiesinrespondingtothesituationifthevessel
is
transportinga widevarietyoftoxicproducts.Itis
importantyetdifficulttohaveafullydetailedlistof
the transported products for the use of assessing
possible dangers for rescue personnel and public.
Based on the analyses of the reviewed accidents,
Mamacaetal.(2009)showedthatthehighest
riskfor
humanhealth comesmainlyfromreactivesubstances
(reactivity with air, water or other products). They
also noted that many chemicals are not only
carcinogenic and marine pollutants, but can form a
moderatelytoxicgascloudwhichisoftencapableof
producing a flammable and/or explosive mix in the
air.
Acrylonitrileis a toxic, fla mmableandexplosive
chemical, and if it is exposed to heat, a highly toxic
gasfor humans (phosgene) is formed. Vinyl acetate,
in turn, is a flammable and polymerizable product
that in the case of Multi Tank Ascania incident (in
United Kingdom, in 1999) caused a
huge explosion.
Little is known about the actual marine pollution
effects of most of these substances. If hazardous
chemicalsandoilarecompared,itcanbesaidthatthe
dangerof coastlinepollutionisafargreaterconcern
foroilspillsthanitisforchemicalspills.Ontheother
hand,
thetoxiccloudsareamuchbiggerconcernin
thecaseofchemicalaccidents(Mamacaetal.2009).
IntheirHNSActionPlan,EMSA(2007)reviewed
pastincidentsinvolvingaHNSorachemical.About
100HNSincidentswereidentifiedfrom1986to2006.
These incidents included both those that
resulted in
spillandthosethatdidnot.EMSA(2007)statedthat
cautionshouldbeappliedtothedataconcerningthe
total sum of the incidents as well as the amount of
spills,because thereisvariabilityinthereportsfrom
different countries. Statistics showed that the
principle cause for both
release and nonrelease
incidentswerefounderingandweather(in22percent
ofalltheincidents),followedbyfireandexplosionin
cargo areas (20 %), collision (16 %) and grounding
(15%). Majority of the accidents involved single
cargoes (73 %), in which most of the material was
carried
in bulk form (63 %). Moreover, 50 % of all
studied incidents resulted in an HSN release. As to
these release accidents/incidents, most of them
happened in the Mediterranean Sea (40 %); some in
the North Sea (22 %) and Channel Areas (20 %),
whereas only 8 per cent occurred in
the Baltic Sea.
Thefounderingandweatherwasagaintheprinciple
causeofthesereleaseincidentsin 34 per centofthe
cases, followed by fire and explosion in cargo areas
(18 %), collision (14 %), and grounding (10 %). The
majority of the incidents resulting in HNS release
involved
single cargoes (78 %) of which 61 per cent
wasinbulkform(EMSA2007).
HASREP project listed major maritime chemical
spills(above70tonnes)intheEUwatersfrom1994
2004 (HASREP 2005). The project found 18 major
accidents altogether, and most of them happened in
France or Netherlands. Interestingly,
8 accidents
listed in HASREP (2005) were not mentioned in the
studyofMamacaetal.(2009).Theaverageoccurrence
of a major maritime chemical accident in the
European Union was nearly 2 incidents per year
(HASREP2005). By comparison, the statistical study
madebytheU.S.CoastGuard(USCG)
intheUnited
Statesover5yearspan(1992–1995)listed423spillsof
hazardoussubstancesfromshipsorportinstallations,
givinganaverageof85spillseachyear.The9most
frequentlyspilledproductsweresulfuricacid(86spill
cases), toluene (42), caustic soda (35), benzene (23),
styrene (20), acrylonitrile (18),
xylenes (18), vinyl
acetate(17)andphosphoricacid(12).Overhalfofthe
spillswerefromships(mainlycarrierbarges),andthe
rest from facilities (where the spill comes from the
facility itself or from a ship in dock). A
complementarystudymadeoveraperiodof13years
(1981–1994)
on the 10 most important port zones
reported 288 spills of hazardous substances,
representing on average, 22 incidents each year (US
Coast Guard 1999). Small spillages in Europe were
not recorded with a similar care because they were
notdetectedand/orthere wasalack of
communicationbetweenenvironmentalorganizations
and
competentauthorities(HASREP2005).
Cedre and Transport Canada (2012) analyzed a
totalof196accidentsthatoccurredacrosstheworld´s
seasbetween1917and2010.Thesubstancesthatwere
most frequently spilled and that had the greatest
quantitiesweresulphuricacid,vegetableoils,sodium
hydroxidesolutionsandnaphtha.Quitesurprisingly,
thestudyshowedthatstructuraldamage(18%)was
the main cause of accidents involving hazardous
materials,followedbysevereweatherconditions(16
%), collision (13 %), and grounding (11 %).
Loading/unloadingwasthecauseforonly7percent
oftheaccidents(CedreandTransportCanada2012).
3.2 Animaland
vegetableoils
Eventhoughvegetableoiltransportvolumeremains
200 times smaller than the volume of mineral oil
transport, it has increased dramatically (Bucas &
Saliot 2002). Thus, the threat of a vegetable oil spill
duetoashipaccidentoraccidentalspillispresently
increasing. Even though vegetable oils
are regarded
as nontoxic consumable products, they may be
hazardous to marine life when spilled in large
quantities into the marine environment. Bucas &
Saliot (2002) observed that there are 15 significant
cases of pollution by vegetable or animal oils that
have been reported during the past 40 years
worldwide.
Rapeseedoilwas involved in five cases,
soybeanoilandpalmoilinthreecaseseach,coconut
oil,fishoil andanchovyoilinonecaseeach, andin
299
two cases the product was unknown. The largest
amountofvegetableoilwasspilledinHawaiiin1975
when M.V. Lindenbank released 9500 tonnes of
vegetable oils to coral reef killing crustaceans,
mollusks and fishes. It also impacted green algae to
grow excessively as well as caused tens of birds
to
die.Similarly,thefishoilaccidenthadalsoaserious
effect on marine environment, killing lobsters, sea
urchins,fishesandbirds(Bucas&Saliot2002).
Based on past cases, Bucas & Saliot (2002)
described the environmental fate of vegetable oil
spills. The specific gravity of vegetable oils is
comprised
between0.9and0.97at20ºCelsius.After
spilledintothesea,theseoilsremainatthesurfaceof
theseaandspreadformingslicks.Thefurtherfateof
theseoilsdependsonthenatureoftheoil,theamount
spilled,theairandseatemperaturesetc.Inopenseas
or
inports,theconsequencesareoftenseverebecause
of local and tidal current movements. The slick can
easily spread over several square kilometers. Few
hours or days after a spill, the slick is usually no
longerregular.Apartoftheoilmaybemingledwith
sand,someofit
mayhavepolymerizedandsunk, and
intheopensea,mechanicaldispersionoftheoilslick
makes it more available to bacterial degradation.
Overallbiologicaldegradationcanbeachievedwithin
14 days, whereas it takes 25 days for a petroleum
product to degrade. If the accident happens in a
shallowbay,
thisbacterial degradationmayresultin
lack of oxygen in the water column (Bucas & Saliot
2002).
Bird loss is usually a major consequence of
vegetable oil spills. Slicks are often colorless with a
slightodor,andthustheyarenot easilydetectedby
birds. Several mechanisms lead birds to
death after
oiling:Forexample,thelossofinsulatingcapacityof
wettedfeathersmakesbirdsdiefromcold;thelossof
mobility makes them as easy catch; the loss of
buoyancyduetocoatedfeathersresultsindrowning;
thelaxativepropertiesoftheoilingestedduringself
cleaning cause lesions; and
the clog of nostrils and
throatcanresulttosuffocation.Astocrustaceans,the
invertebrates have died, for instance, from
asphyxiation of clogging of the digestive track.
Anoxia of the whole water column may also be the
causeofthesedeaths, andthereisalsoevidencethat
e.g. sunflower oil
can be assimilated on tissues of
mussels,asithashappenedinthecaseoftheKimya
accident (Bucas & Saliot 2002, Cedre 2012). Bucas &
Saliot (2002) stated that it is necessary to quickly
collect the oil after spillage by using usual methods
likeboomsandpumps.
3.3 Riskassessment
ofdifferentchemicals
Risk posed by maritime chemical spill depends also
on accident scenario and environmental conditions
besides inner properties of the spilled chemical.
Basically,accidentsinvolvingchemicaltankerscanbe
classifiedintofourgroups.Offshore,intheopensea
area,chemicalspillhasspacetohavealargereffect
or
to dissolve and be vaporized. This mitigates the
negative effects of the spill. On the other hand,
response actions can take a longer time and
environmentalconditionscanbechallenging,aswell.
The incident occurring closer to shoreline can be
easier or faster to reach, even if the impact to
the
environmentcanpotentiallybemoredisastrous.The
third scenario portrays a casualty that happens in a
closedseaarea,likeinaportorinaterminalarea.In
these cases, the spill is usually localized and
effectively restricted. However, even smaller spill
may elevate toxicitylevelsina
restricted area. Ports
are also situated near city centers, and there is an
elevatedriskforthehealthofthepublicandworkers
in the area. The fourth possibility is an accident
during winter in the presence of ice and snow
(Hänninen & Rytkönen 2006). The properties of the
chemicalsmay
changeincoldwater.Somechemicals
maybemoreviscousorevenbecomesolids,andthus,
easier to recover. On the other hand, hazardous
impactsofsome chemicalsmay multiplyinthecold
environment because the decomposition of the
chemicalsbecomesslower.Thus,chemicalsmaydrift
to larger areas. They
may also accumulate to the
adipose tissues in animals which decreases the
probability of an animal to survive beyond winter
(Riihimäkietal.2005).
The marinepollution hazards caused by
thousands of chemicals have been evaluated by, for
example, the Evaluation of Hazardous Substances
Working Group which has given GESAMP Hazard
Profileasaresult.Itindexesthesubstancesaccording
to their bioaccumulation; biodegradation; acute
toxicity;chronictoxicity;longtermhealtheffects;and
effects on marine wildlife and on benthic habitats.
Based on the GESAMP evaluation, the IMO has
formed 4 different hazard categories: X (major
hazard),Y(hazard)
andZ(minorhazard)andOSi.e.
othersubstances(nohazard)(IMO2007).Over80per
cent of all chemicals transported in maritime are
classified as belonging to the Y category (GESAMP
2002;IMO2007).ThisGESAMPcategorizationisvery
comprehensive, but different chemicals having very
differenttoxicitymechanisms,environmentalfate
and
other physicochemical properties may end up to
same MARPOL category. The GESAMP hazard
profile, although being an excellent firsthand guide
in a case of a marine accident, will not answer the
questionofwhichchemicalsbelongingtothesameY
category are the most dangerous ones from
an
environmentalperspective.
Many risk assessment and potential worst case
studiesexistto help find out whatimpacts different
chemicals might have if instantaneous spill were to
happen (Kirby & Law 2010). For example, Law &
Campell(1998)madeaworstcasescenarioofcirca10
tonnes insecticide spill (pirimiphosethyl),
and
concludedthatitmightseriouslydamagecrustacean
fisheriesinanareaof10,000km
2
witha recoverytime
of5years.Inthecaseofmarineaccidents,thegreatest
risktotheenvironmentisposedbychemicalswhich
have high solubility, stay in the water column, and
are bioavailable, persistent and toxic to organisms.
Basedontheanalysisofchemicalstransportedinthe
Baltic
Sea, Häkkinen et al. (2012) stated that
nonylphenolisthemosttoxicofthestudiedchemicals
anditisalsothemosthazardousinlightofmaritime
spills. The chemical is persistent, accumulative and
hasarelativelyhighsolubilitytowater.Nonylphenol
is actually transported in the form of nonylphenol
ethoxylates
but it is present as nonylphenol when
spilledtotheenvironment,andintheaforementioned
300
study the worst case scenario was evaluated. Other
very hazardous substances were sulphuric acid and
ammonia (Häkkinen et al. 2012). Similarly, the
HASREP (2005) project identified top 100 chemicals
whicharetransportedbetweenmajorEuropeanports
andinvolvedintradethroughtheEnglishChannelto
therestoftheWorld.
Theassessmentwasbasedboth
on tra nsport volumes and the GESAMP hazard
profile. The project highlighted chemicals such as
benzene, styrene, vegetable oil, xylene, methanol,
sulphuric acid, phenol, vinyl acetate, and
acrylonitrile. It was concluded that these chemicals
weretheonesthathavehighspillageprobabilitybut
may not result
in significant environmental impact.
Similarly, French McKay et al. (2006) applied a
predictivemodelingapproachforaselectedrangeof
chemicals that are transported by sea in bulk and
concludedthatphenolandformaldehydepresentthe
greatest risks to aquatic biota. Harold et al. (2011)
evaluated human health risks of transported
chemicals,basedontheGESAMPratingsfortoxicity
and irritancy. This gives more weight to chemicals
thatarefloaters;formgasclouds;orareirritableand
toxiclikechlorine(Haroldetal.2011).Itisclearthat
different weightings have a certain impact on the
difference in results in these
studies. However, the
chemicalsofrealconcernvarydependingonthesea
areaforwhichtheriskassessmentisconductedsince
theamountsandtypesofchemicalsdifferindifferent
seaareasasdomarineenvironmentandbiota(Kirby
&Law2010).
Theimpactsof areleaseoraspill depend
onthe
behaviorofthechemical orchemicalsinquestion. It
canbeconcludedthatthemostharmfulchemicalsfor
humanhealthhavequiteoppositepropertiestothose
thatare most hazardous for water biota. Forhuman
health, the most hazardous chemicals are those that
arevery reactive, formeither
very toxic or irritating
(orexplosive)gasclouds,andalsohavepossiblelong
term effects, such as carcinogenic effects. From the
environmental point of view, the most hazardous
chemicalsare thosethatsink,havea highsolubility,
possibly stay at the water column, are persistent,
bioavailable and very toxic and can
have possible
longtermeffects(FrenchMcKayetal.2006,Häkkinen
etal.2012,Haroldetal.2011).
3.4 Responseactionsincaseofmaritimechemicalspills
There are many excellent reviews (e.g. Marchand
2002, EMSA 2007, Purnell 2009), based on lessons
learnedfrompastaccidents,whichalsocontaindata
aboutresponseactionsincaseofchemicalspills.Even
ifresponseactionstakendifferineveryaccidentcase
according to special conditions and chemicals
involved, it is nevertheless possible to demonstrate
certain significant or specific elements valid in all
chemicalincidentsatsea(Marchand2002).
Firstly, like the information concerning the
ship
cargo, an evaluation of chemical risks is of primary
importancebeforeanyoperationaldecisionsaretobe
made,especiallyiftheshipiscarryingawidevariety
ofchemicals(Marchand2002).Followingthechemical
spillatsea, the responseauthorities must
immediatelytakemeasuresinorder tominimizethe
chemical exposure to the public as well as
contamination of the marine environment. The
primary factors which determine the severity and
extentoftheimpactoftheaccidentarerelatedtothe
chemicalandphysicalpropertiesofthechemicalsin
question. It should be noted that in the case of oil
spills, the hazard to human health is generally
consideredtobelow,andthemoretoxicandlighter
fractionsoftenevaporatebefore responseactions are
able to be started. However, in case of chemical
accidents, an initial assessment and monitoring of
potentialhazardsshouldbeundertakenfirstinorder
to
ensureasafe workingenvironment.Inthatstage,
theprimaryhazardsandfateofthechemicalinthat
marine environment are evaluated. The monitoring
techniques need to be designed to measure the key
parametersthatcouldgiverisetoahazard.Itshould
alsobenotedthatinsomecasesdoing
nothingmight
be the best option, as long it happens under
observation(Marchand 2002,Purnell2009).LeFloch
et al. (2010) stated that in case of an instantaneous
chemical spill, response usually follows three
accepted scenarios: 1) response is not possible,
because the spill occurred in a geographical
environment that
is incompatible with reasonable
response times, 2) response is not possible due to
reactivityofthesubstances(major,imminentdanger),
and 3) response is possible. Gases and evaporators,
very reactive substances, and explosives are the
biggestconcernforhumanhealthandsafety.Several
monitoring devices and dispersion models exist
which may
aid decision making and help protect
responders and the public. The floaters can be
monitoredbyusingthesametechniquesthatareused
for oil spills. Chemicals that prove to be the most
difficult to be monitored are sinkers and dissolvers
(suchasacrylonitrileinthecaseofAlessandroPrimo
in Italy in 1991), even if some techniques e.g.
electrochemical methods and acoustic techniques
exist(EMSA2007,Purnell2009).
Several international, regional and national
authorities have published operational guides to
describe the possible response options in case of a
chemical spill. For example Cedre and IMO have
mademanualsprovidinginformation
aboutdifferent
response techniques that can be used in case of
chemical spills (Cedre 2012, HELCOM 2002, IMO
2007). Usually response techniques depend on the
behavior of a chemical in the environment, and on
whether it is released or still contained in pa ckaged
form. In pra ctice, the response action varies
substantially.Techniquesthatareapplicableincaseof
oil accidents may be suitable for only some floating
chemicals. However, it should not be forgotten that
some floating chemicals can also potentially create
toxic and maybeexplosive vapor clouds (e.g. diesel,
xyleneandstyrene).Ifthishappens,thespark/static
free equipment should
be used. Moreover, foams or
sorbent materials can also be used near the spill
source. Risks associated with evaporators or gases,
such as ammonia and vinyl chloride, could be
diminished by diluting or using release methods
(Purnell 2009). In shallow water areas, neutralizers,
activated carbon, oxidizing or reducing agents,
complexing
agents, and ionexchangers canbe used.
Chemicals that are heavier than seawater, in turn,
maycontaminatelargeareasoftheseabed.Recovery
methodsthatareusedincludemechanical,hydraulic
orpneumaticdredges,buttherecoveryworkistime
301
consuming and expensive and results in large
quantities of contaminated material. Other option is
capping the contaminated sediment insitu (Purnell
2009).
As Marchand (2002) listed, the time involved in
responseoperationscanvaryfrom2–3months(Anna
Broere, Holland; Cason, Spain; Alessandro Primo,
Italy); to 8 months (Fenes, France); to 10 months
(Baham
as, Brazil); or to even several years as in the
case of the research carried out on a sunken cargo
(Sinbad, Holland). Cold weather and ice cover may
create further problems to response actions in the
Baltic Sea in the winter. The viscosity of chemicals
maychangeincold,andtheycanbemorepersistent.
Collect
ing techniques based on fluidlike masses are
nolongereffective,iffluidschangeandactmorelike
solid masses. Moreover, it is difficult for a recovery
fleettooperate,ifitissurroundedbyiceandsnow.If
chemicalshavespreadundertheicecover,detecting
the spill is more difficult
, and the use of dispersing
agents is ineffective. However, ice breakers may be
used to break the ice cover and to improve mixing
chemicals with larger water masses (Hänninen &
Rytkönen2006).
4 STATISTICALREVIEWONTANKER
ACCIDENTSINTHEBALTICSEA
4.1 AccidentstatisticsbyHELCOMandEMSA
The Helsinki Commission (HELCOM) has reported
tha
t during the years 1989–2010 approximately 1400
shipaccidentshappenedintheBalticSea.Mostofthe
accidents were groundings and collisions, followed
bypollutions,fires,machinerydamagesandtechnical
failures (Fig. 1). One in ten of the accidents are
definedasothertypesofaccidents(HELCOM2012).
Groundings44%
Collisions28%
Pollution7%
Fire6%
Machinerydamage
3%
Technicalfailure2%
Otheraccident10%
Figure1.VesselaccidentsintheBalticSeain1989–2010by
accidenttypes.(HELCOM2012)
According to HELCOM (2012), 1520 vessels in
totalhavebeeninvolvedintheaccidentsoccurredin
theBalticSeaduringtheyears1989–2010.Almosthalf
of the vessels were different types of cargo vessels
excluding tankers (Fig. 2). Large number of other
vessel types (e.g. pilot vessels, tugs, dredgers) was
also involved in the accidents. One in seven of the
accidentsinvolvedata
nkerandapassengervessel.
Cargovessels(excl.
tankers)47%
Tankers 14%
Passengervessels
14%
Othertypesof
vessel24%
Noinformation1%
Figure2.VesselaccidentsintheBalticSeain1989–2010by
vesseltypes.(HELCOM2012)
Tanker
accidents
withno
pollution86,7
%
Oil/oil
product
pollution
cases12,8%
Chemical
pollution
cases0,5%
Total numberoftankeraccidents:211
Amount ofpollutionintotal:appr.3100m3
Figure3.Tankeraccidentsandtheshareofpollutioncases
intheBaltic