safety data sheet

National Oil Spill 

Contingency Plan 

Chapter 7 – Dispersant Use

Contents 

Contents ................................................................................................................................................... 2 

Maritime New Zealand’s Position on Dispersants for Oil Spill Response ................................................ 3 

Maritime NZ approved dispersants ................................................................................................... 3 

Deciding whether to use dispersants ................................................................................................ 3 

Window of opportunity ...................................................................................................................... 3 

Areas where dispersant should not be applied ................................................................................. 3 

Dispersant effectiveness ................................................................................................................... 3 

Dispersant effectiveness in freshwater ..................................................................................... 4 

Effectiveness test results of Maritime NZ dispersant stocks ..................................................... 4 

Effectiveness test results of Maritime NZ dispersant stocks on NZ Crude Oils ........................ 5 

Dispersant Application .............................................................................................................................. 5 

Sea state ........................................................................................................................................... 5 

Calm conditions ......................................................................................................................... 5 

Rough conditions ...................................................................................................................... 5 

Dispersant application options .......................................................................................................... 6 

Backpacks ................................................................................................................................. 6 

Vessel-based ............................................................................................................................ 6 

Fixed-wind aircraft ..................................................................................................................... 6 

Helicopter .................................................................................................................................. 6 

Application rates ............................................................................................................................... 6 

Telling when dispersion has occurred ....................................................................................... 7 

Material Safety Data Sheets ..................................................................................................................... 9 

Slickgone LTSW ........................................................................................................................ 9 

Corexit 9527 ............................................................................................................................11 

Corexit 9500 ............................................................................................................................18 

OSR-LT ...................................................................................................................................25 

Tergo 2-005 .............................................................................................................................42 

National Marine Oil Spill Contingency Plan Page 2 of 45 

Chapter 7 – Dispersants Use Issue 7 June 2012

Maritime New Zealand’s Position on Dispersants for Oil Spill 

Response 

It is the policy of Maritime New Zealand that no marine oil spill response option should be ruled out or 

limited in advance. This is particularly true for dispersants. Chemical dispersants are an important 

option which should always be considered in the most effective ‘first stage’ of a response strategy. 

Maritime NZ approved dispersants 

Only dispersants approved for use in New Zealand marine waters in accordance with the marine 

protection rules Part 132 (1998) can be considered for use. 

Dispersants currently approved for use in New Zealand are listed at the rear of this Chapter. 

Deciding whether to use dispersants 

Maritime NZ has developed “Guidelines for the Use of Oil Dispersants in New Zealand”. The 

guidelines provide the decision-making framework to reach and document dispersant decisions. Any 

consideration of dispersant use should follow the procedures described in the Guidelines. 

The Guidelines include information on: 

assessing environmental risk, 

whether dispersant use is appropriate, 

notification, 

assessing likely oil dispersion, 

determining dispersant availability, 

safety, 

determining effectiveness of applications, and 

response termination. 

Window of opportunity 

The window of opportunity is the estimated time period available during which chemical dispersants 

will effectively disperse oil into the water column. The window of opportunity will vary with different oil 

types, the conditions prevailing during a spill, the types of dispersant available, and the method of 

application. 

Areas where dispersant should not be applied 

All New Zealand marine waters are classified as pre-approved for dispersant use under the New 

Zealand Marine Oil Spill Response Strategy. However, there may be areas where it is unacceptable 

for dispersant to be used based on the pre spill analysis of net environmental benefit. Some of these 

areas are identified in Annex 4 (Sensitive Areas and Coastal Information) of the Regional Plans. Other 

areas, for example around intake structures, may be identified during the response process when 

there is more certainty about the volume and nature of the oils and resources at risk. Although 

Regional Marine Oil Spill Contingency Plan may designate areas where dispersant should not be used 

the National On-Scene Commander may direct that dispersants be used in such areas if they consider 

a net environmental benefit will accrue. 

Dispersant effectiveness 

Section 5 of the Guidelines for the use of Oil Spill Dispersant (Stevens 2006) describes the general 

properties of oils and their likely dispersibilty. However estimates of effectiveness based solely on oil 

properties are unreliable and direct assessment of the spilt oil should be used wherever possible. 



Crude oil 

source 

Dispersant effectiveness in freshwater 

DISPERSANT SALT WATER FRESH WATER 

Gamlen OSD LT Yes Yes 

Tergo R40 Yes Yes 

Corexit 9500 Yes Not recommended 

Corexit 9527 Yes Not recommended 

Shell VDC Yes Not recommended 

The largest impact for regional and national marine oil spill response is the fact that neither Corexit 

9527 nor Shell VDC are recommended for use with fresh water. This effectively precludes both of 

these dispersants for use in fresh water environments. 

Effectiveness test results of Maritime NZ dispersant stocks 

The following table presents a summary of NZ laboratory effectiveness test results (WSL LR448 test 

protocol) undertaken at 15oC, on unweathered oil, at a dispersant to oil ratio (DOR) of 1:25. Shaded 

cells indicate effectiveness criteria which indicate that dispersion of fresh oil may be possible. 

Viscosity 

(mPas, 10s-1 

shear rate) 

Corexit 

9500 

Corexit 

9527 

Gamlen 

OSDLT 

Slickgone 

LTSW 

Tergo 

R40 

Wooly Butt 3 � � � � - - 

Murban 6 � � � � - - 

Kutubu 11 � � � � � - 

Barrow Island 12 � � � � � - 

Labuan 14 � � � � � - 

Arab Light 31 - � � � � - 

Kuwait 38 � � � � � - 

Oman 47 - � � � � - 

Oman Residue 2058 � � � � � - 

Residue - � � � � � - 

IFO-380 fuel oil 

source 

KeeLung, Taiwan 2908 � � � � � � 

Santos, Brazil 6294 � � � X � - 

Cristobel 8000 � � � X � - 

Tokyo 9155 � � � � � - 

Nagoya 12086 � � X X X - 

Singapore 13268 � � X � X � 

Rotterdam/Flushing 15200 � � X X X - 

Antwerp 90325 � X X X X - 

Notes: 

All testing conducted by Cawthron on unweathered oil at 15°C using the WSL LR 448 protocol 

modified with a 5 minute mixing period. N=2 

All dispersants applied at DOR of 1:25 as Type III dispersants 


Chapter 7 – Dispersants Use Issue 7 June 2012 

Tergo 

2005

- indicates not tested 

� Shading indicates 15% effectiveness criterion used to indicate likely field effectiveness 

Test method generally underestimates dispersant effectiveness on light crude oils and overestimates 

dispersant effectiveness on fuel oils 

Full test results avavilable in Cawthron Technical Reports 

Effectiveness test results of Maritime NZ dispersant stocks on NZ Crude Oils 

Crude oil 

source 

Water 

Temp 

Corex 

it 

9500 

Corex 

it 

9527 

Gam 

len 

OSD 

LT 

Slickg 

one 

LTSW 

Slickg 

one 

NS 

Tui Crude 15º X � X � X X 

10º X 

Tergo 

2005 

Comment 

Maari Crude 18.5º � X X X X X - The oil can be dispersed only 

at the earlier stage of its 

weathering, 

- Weathered oil, with its high 

pour point, is not favorable to 

chemical dispersion. 

Manaia 

Crude 

18º 

10º 

Kupe Condensate - Kupe Condensate has a relatively high pour point and high wax content. If 

the seawater temp is above the oil pour point, natural dispersion and 

evaporations rates are likely to be high. Chemical dispersion is generally 

undesirable because it will reduce evaporative losses and transfer the most 

toxic oil fractions into the water. 

- When sea temperature is below the pour point, or following weathering, 

spilt oil is likely to solidify relatively quickly or form a low toxicity waxy residue 

after the light ends evaporate. In either state, the effectiveness of chemical 

dispersants will be greatly limited as it will be difficult to apply them at the oilwater 

interface where they work. 

Maui Condensate Dispersant use not considered necessary due to rapid evaporation of vast 

majority of oil. 

Dispersant Application 

Sea state 

Calm conditions 

In very calm conditions there may be insufficient energy in the sea to create the small droplets 

required for effective dispersion of the oil. Consequently, care must be taken to ensure that either 

suitable agitation is provided to break up the treated oil or dispersant is not applied in these conditions. 

Rough conditions 

When the wind reaches Force 5 (17 – 21 knots) and above, the natural turbulence of the sea means 

that oil will be regularly covered by breaking waves. Under these conditions the application of 

dispersants can lead to excessive wastage as the water prevents dispersant reaching the oil. In 



addition fine droplets are blown away from the spray area. Thus in these conditions spraying is not 

recommended. 

Dispersant application options 

Backpacks 

Backpacks are light, portable and cheap, but have a small payload and low application rate. They can 

be useful for application from small boats for limited treatment in difficult to access areas such as 

around wharf piles. It is easy to exceed recommended dose rates using backpack applicators. 

Vessel-based 

Vessel-based systems can be fitted to many types of vessel, but the oil encounter rate is quite low. As 

slicks are not of uniform thickness, boats need to be directed by spotter aircraft to areas of thicker oil. 

Fixed-wind aircraft 

Fixed-wing aircraft based systems allow a rapid response and a high treatment rate. Small aircraft 

(e.g. crop spraying aircraft) have a small payload but are useful for near-shore waters. However they 

require adaptation and this takes time. Spray nozzles used for crop spraying may not be suitable for 

dispersant spraying and therefore have to be changed if they are unable to deliver droplets of 400µm 

– 1000µm. 

Helicopter 

Helicopter-based systems can operate from a base near the spill, and can be used on small spills in 

confined or inaccessible situations. The spray nozzles used for crop spraying may not be suitable for 

dispersant spraying and therefore have to be changed if they are unable to deliver droplets of 400µm - 

1000µm. 

Application rates 

The ratio of dispersant to oil required for effective dispersal varies between 1:5 and 1:30. Depending 

upon the type of oil and prevailing conditions. As a general guide, a dispersant starting ratio (dose 

rate) of between 1:20 and 1:30 is recommended. 

In calculating application rates an allowance must be made for losses of dispersant spray during its 

passage through the air to the sea surface. It is essential to reduce to a minimum those losses due to 

wind drift and air turbulence. Large droplets assist in this respect but in addition the aircraft should be 

flown as low as safety considerations allow. Typically an altitude of 5 – 15m should be used. 

Dispersant should be applied as droplets with a mean diameter in the range 600 – 800 m. 

1. Determine thickness of oil: 

As a general rule, most liquid oils spread to an average thickness of 0.1mm. 

2. Determine volume of oil in one hectare: 

volume = oil thickness (m) x 10,000 m2 

(0.1mm thickness = 1m3 or 1000 litres) 

3. Determine application rate: 

Application rate (litres/hectare) = volume / dose ratio 

Typical starting ratios of dispersant to oil are between 1:20 and 1:30. 

(for a dose ratio of 1:20 the appropriate application rate would be 1000/20 = 50 litres/hectare 

0.005 litres/m2) 

4. Determine application speed or discharge rate (depending on known variables): 

discharge rate (litres/sec) = application rate (litres/m2) x swath (m) x speed (m/s) 

speed (m/s) = discharge rate (litres/sec) 



Telling when dispersion has occurred 

application rate (litres/m2) x swath width (m) 

A visible subsurface plume of dispersed oil indicates that an application of dispersant is working. 

When no plume is visible in the water column, it is difficult to determine whether the dispersant is 

working, but does not definitively mean that the dispersant is not having an effect. 

Subsurface plumes of dispersed oil typically have a cloudy appearance, and can range in colour 

from brown to white. Some are not visible. When dispersant is working, oil remaining on the water 

surface also may change colour. 

In some cases, you may not be able to see a subsurface plume even when one is present. When 

the water is turbid, you may not be able to see a plume. Sometimes, remaining surface oil and 

sheen can mask oil dispersing under the slick, making it hard for you to see the plume. 

A subsurface plume may not form instantaneously once dispersant has been a[applied to slick. 

In some cases, such as when oil is emulsified, it can take several hours for a plume to form. In 

other cases, a visible plume may not form (you then may wish to use sampling to learn whether 

dispersion has occurred) 



New Zealand Approved Oil Spill Dispersants 

Prior to use in New Zealand marine waters, dispersants must be approved in accordance with the Marine Protection Rules Part 132: Dispersants and 

Demulsifiers (or previously approved under the Marine Pollution (Dispersants and Exceptions) Regulations 1975). 

Currently-approved dispersants are listed in the table below: 

Dispersant Dispersant Dispersant 

1100X Enersperse 1037 Shell Dispersant VDC 

1100WD Gamlen Oil Dispersant LT Slickgone LTSW 

A-B OSR LT Slickgone NS 

Atlas OSD Quell Oil C1 Solvex OSD 9 Concentrate 

Atpet 787 SD LT[X] Surflo-OW1 

Corexit 9500 Shell Dispersant Concentrate Tergo 200-5 

Corexit 9527 Shell Dispersant HEC Tergo Oil Spill Remover low toxic 

Corexit 9600 Shell Dispersant LTX Tergo Oil Spill Remover WSA 

Drew Ameroid Oil Spill Dispersant Shell Dispersant ND Tergo R40 

MNZ stockpiled Oil Spill Dispersants 

Company Contact Numbers Brand Comment 

Chemetal Industries Ltd 

PO Box 15783 New Lynn 

AUCKLAND. 

Address: 664 Rosebank Rd 

Avondale 

Ashland New Zealand 

119 Carbine Road 

Mt Wellington 

AUCKLAND 

Nalco-Exxon Chemicals Ltd 

PO Box 3137 

NEW PLYMOUTH 

Dasic International Ltd 

Winchester Hill, Romsey, 

Hants SO51 7YD, UK 

Ph: (09) 820 3888 

Fax: (09) 820 3979 

Lorraine du Plessis 

Mob 027 444 6970 

Peter Slijp 

Tel: (09) 276 6620 

Fax: (09) 276 6690 

Email: pslijp@drewnz.co.nz 

Tel: (06) 758 4428 

Fax: (06) 757 9648 

Gordon McGowan 

DDI 06 215 4299 

Tel: +44(0)1794512419 

Fax: +44(0)1794522346 

Tergo 2 – 005 

Gamlen Oil Dispersant LT 

Corexit 9500 

Corexit 9527 

Slickgone LTSW 

Slickgone NS (Available via 

AMSA stockpile) 


Chapter 7 – Dispersants Use Issue 7 June 2012 

This is carried in stock and can be manufactured on 

request as they carry raw ingredients. 

Can usually manufacture on request large batches (eg 20 

x 200 litre drums) 

Have no stocks in the country but can bring them in.

Material Safety Data Sheets 

Slickgone LTSW 





Corexit 9527 















Corexit 9500 















OSR-LT 



































Product Name 

SAFETY DATA SHEET 

Section 1: Chemical Product and Company Identification 

Tergo 2-005 

Synonyms Oil Spill dispersant Type 

III 

Recommended 

Use 

Date of 

Preparation 

Contact 

Details: 

Supplier Tergo Industries Ltd 

Address 664 Rosebank Rd, Avondale 

Dispersant for emergency Auckland 

response to oil spill New Zealand 

21 April 2009 Telephone No. +64 9 820-3888 

Section 2: Hazard Identification 

Hazard Classification 3.1D, 6.4A 

Hazards Statements Warning: 

Combustible Liquid 

Causes eye irritation. 

Precautionary 

Statements 

Emergency No. NZ 0800 POISON (0800 764 

766) 

AUS 131126 

Keep away from heat/sparks/open flame. 

Wear eye/face protection 

Store in well ventilated place 

If in eyes rinse cautiously with water for several minutes. Remove contact 

lense if present and easy to do so. Continue rinsing. 

Wash hands after handling. 

Section 3: Composition/Information On Ingredients 

Chemical C.A.S No. Proportion 

(low

Notes For Medical 

Personnel 

Remove contact lense if present and easy to do so. Continue 

rinsing. 

Skin Remove contaminated clothing. Flush affected area with 

running water Launder contaminated clothing before re-use. 

Inhalation Remove to fresh air. 

Treat symptomatically. If aspirated into the lungs during 

ingestion, 

or from vomiting, chemical pneumonitis or pulmonary 

oedema may occur. 

Section 5: Fire Fighting Measures 

Hazards Flammable after moderate preheating and therefore will support combustion 

under extreme conditions of a fire. 

Extinguishing Foam, dry chemical powder, Carbon dioxide, water spray or fog (large fires 

Media 

only) 

Protective Gear Fire fighters must use recommended protective equipment and self-contained 

breathing apparatus. Hazchem Code 3[Y] 

Section 6: Accidental Release Measures 

Small Spills Shut off ignition sources. Absorb spill with inert material and place in container for 

removal by approved waste management facility. 

Large Spills Remove all ignition sources. Wear protective gloves and safety glasses. Increase 

ventilation. Contain spill with sand, earth or vermiculite. Collect recoverable product 

into labelled containers for removal by approved waste management facility. 

Section 7: Handling and Storage 

Handling Use good occupational work practice. Wear recommended Personal 

Protective Equipment (PPE) and observe precautions in section two of this 

safety data sheet. 

Storage Site Store away from heat and open flames. Store at ambient temperatures. 

Keep containers tightly closed and in a well ventilated place. 

Packaging Where possible keep in manufacturer’s original container. If container 

deteriorates or decanting to smaller quantities the new packaging should be 

sturdy polyethylene /polypropylene 

Section 8: Exposure Controls/Personal Protection 

Workplace Exposure 

No value assigned by NZ OSH but 2000 mg/m 

Standards 

3 TWA recommended 

based on generic equivalents 

Engineering Controls In general, dilution ventilation is a satisfactory health hazard control 

for this substance. 

Personal Protective 

No special equipment needed when handling small quantities. In an 

Equipment 

industrial environment with large quantities involved, safety glasses, 

PVC gloves and safety footwear are recommended. 

Section 9: Physical and Chemical Properties 

Appearance: Clear to slightly hazy, amber liquid with characteristic 

hydrocarbon odour. 

Boiling Point (°C): 296 

Vapour Pressure (kPa @ 20°C) 200 

Water Solubility Miscible 

Plus other properties if applicable 



Section 10: Stability and Reactivity 

Stability Considered stable under normal conditions 

Conditions/Materials to Avoid Sources of heat and ignition, open flames. Strong oxidizing 

Hazardous Decomposition 

substances. 

Thermal decomposition will produce Carbon Dioxide, and 

Products 

Monoxide and oxides of sulphur 

Hazardous Polymerisation Will not occur 

Section 11: Toxicological Information 

Minimal toxicity and irritation potential. 

CAUTION: these values represent established data on individual components of the product and must 

be interpreted in conjunction with the proportion of that component in the product. 

Component % by 

wt 

Value End Point Route Species 

Hydrotreated light distillate 10-60 15000mg/kg LD50 Oral rat 

Carcinogenicity OSHA: NO IARC: NO NTP: NO 

Section 12: Ecological Information 

Species Exposure (hours) End Point Value 

Rock oyster 48 EC50 15 

Tiger Prawn 96 EC50 15 

Mysid Shrimp 96 LC50 >80 

Sea Urchin 72 EC50 15.96 

Section 13: Disposal Consideration 

Dispose in accordance with all applicable local regulations. Contact a licensed waste disposal facility 

to assure compliance 

Land (NZS 5433 Proper Shipping 

Name 

Nil 

and ADG) Class Nil 

UN No. Nil 

Packing Group n/a 

Hazchem Code n/a 

Sea (IMDG/IMO) Proper Shipping 

Name 

Nil 

Class Nil 

UN No. Nil 



Air (IATA) Proper Shipping 

Name 

Nil 

Class Nil 

UN No. Nil 



Section 14: Transport Information 

Section 15: Regulatory Information 

HSNO Approval HSR002490 



Code 

HSNO 

Classifications 

3.1D,6.4A 

HSNO Controls Trigger Quantity 

Approved Handler Not required 

Site location Certification Not Required 

Hazardous Atmosphere Zone Not required 

Signage Required 10,000L 

Emergency Plan & Secondary 

Containment 

10,000L 

Fire Extinguishers 500L 

Section 16: Other Information

safety data sheet

Create successful ePaper yourself

Delete template?

Save as template?