Fuel dye

From Wikipedia, the free encyclopedia
(Redirected from Fuel dyes)
Plastic jerrycan containing 'red' diesel.

Fuel dyes are dyes added to fuels, as in some countries it is required by law to dye a low-tax fuel to deter its use in applications intended for higher-taxed ones. Untaxed fuels are referred to as "dyed", while taxed ones are called "clear" or "white".

Aviation gasoline is dyed, both for tax reasons (avgas is typically taxed to support aviation infrastructure) as well as safety (due to the consequences of fuelling an aircraft with the wrong kind of fuel).

Types of dyes[edit]

The dyes used have to be soluble in the fuels they are added to and therefore in hydrocarbon-based nonpolar solvents ("solvent dyes"). Red dyes are often various diazo dyes, e.g., Solvent Red 19, Solvent Red 24, and Solvent Red 26. Anthraquinone dyes are used for green and blue shades, e.g., Solvent Green 33, Solvent Blue 35 and Solvent Blue 26.

The pure dyes found in modern liquid petroleum dyes are longer alkyl side chain forms of traditional dyes and normally multiple chain length variations of the chromophore are found within a typical commercial liquid petroleum dye. For instance, Sudan Red 462 is a form of Solvent Red 19, with the ethyl side chain replaced by either a 2-ethylhexyl or a tridecyl side chain. The longer branched side chains improve solubility dramatically, but in some cases the high solubility prevents the dye being isolated as a crystal, except at very low temperatures. The high-solubility liquid dyes originated with Morton International and BASF (ACNA Italy) as the primary inventors. For instance, Morton International created Solvent Blue 98 as a high solubility form of Solvent Blue 35. BASF created Solvent Blue 79 as its high solubility form of Solvent Blue 35. In some cases it is possible, with normal solvents—e.g., xylene—to prepare stable (to -20C) solutions at 65% "solids" content. The original powder dye form of the chromophore would not be soluble beyond 2% in xylene.

Only a few refineries worldwide still use powder dyes for colouring fuels, as although they are lower cost per active molecule of dye chromophore than the modified forms, they have significant handling issues and health and safety issues that inherently arise from the handling of azo dyes (reds/yellows/green mixes). It is advantageous to mix a liquid with a liquid instead of handling powdered dyes into a liquid.

Fuel dye in Europe[edit]

After August 2002, all European Union countries became obliged to add about 6 mg/L (0.034 oz/bbl) of Solvent Yellow 124, a dye with structure similar to Solvent Yellow 56, to heating fuel. This dye can be easily hydrolyzed with acids, splitting off the acetal group responsible for its solubility in nonpolar solvents, and yielding a water-soluble form. Like a similar methyl orange dye, it changes color to red in acidic pH. It can be easily detected in the fuel at levels as low as 0.3 ppm by extraction to a diluted hydrochloric acid, allowing detection of the red diesel added into motor diesel in amounts as low as 2–3%. The European Union has announced that a new and better marker has been found to replace Solvent Yellow 124.[1][2][3] On 14th February 2022 the EU Commission published their decision dated 17th January 2022 naming the new marker as "ACCUTRACE(TM) Plus" ButoxyBenzene with a transition date ending 18 January 2024 [4]

United Kingdom[edit]

Motor Spirit (Regulation) Act 1948
Act of Parliament
Long titleAn Act to create certain offences in connection with the supply and use of motor spirit, and for purposes connected therewith.
Citation11 & 12 Geo. 6. c. 34
Royal assent28 May 1948
Petrol station in England, with 'red diesel' available for a lower price, but only for "off road use", i.e. agricultural machinery and similar.
Fuel pumps in Ireland, with green gas oil and red kerosene, and notices that it is an offence to use marked fuels in a motor vehicle.

In the United Kingdom, "red diesel" is dyed gas oil for registered agricultural or construction vehicles such as tractors, excavators, cranes and some other non-road applications such as boats. Red diesel carries a significantly reduced tax levy compared to un-dyed diesel fuel used in ordinary road vehicles. As red diesel is widely available in the UK, the authorities regularly carry out roadside checks. Unauthorised use incurs heavy fines but despite this, spot checks have occasionally found as many as one in five motorists using red diesel.[5]

Red diesel can also be used in road vehicles which are registered as off road with the DVLA provided they are only used on private land. On 14 July 2014, the European Commission announced it was referring the United Kingdom to the European Court of Justice over the use of red diesel in propelling private pleasure craft on water. It believed the UK was not properly applying EU regulations for the fiscal marking of fuels.[6]

On 18 November 2014, a new measure to combat fuel laundering was set to result in the illegal trade being "virtually eliminated" in the United Kingdom, according to HM Revenue and Customs. A new dye was introduced in April 2015 in the United Kingdom and the Republic of Ireland.[7]

Carbon offset red diesel[edit]

Carbon offset red diesel is, as of 2014, available in the UK. It is marketed as an environmentally friendly alternative to regular red diesel. There is an extra cost incurred when purchasing carbon offset red diesel; however, some[clarification needed] suppliers of the fuel are donating the extra cost to projects aimed at lowering carbon emissions, meaning they make no extra profit from the sale of the fuel.[8]


Diesel (black) and dyed fuel oil (MPÖ; red) dispensers at a St1 petrol station in Tornio, Finland.

Low-tax dyed fuel oil (Finnish: polttoöljy; Swedish: brännolja; always abbreviated on nozzles as MPÖ) is available in many rural petrol stations in Finland, primarily intended for certain types of non-road vehicles such as tractors and driveable construction vehicles. Until 2002, furfural was used to dye fuel oil in Finland, when it was replaced with Solvent Yellow 124. Since 2008, boats and pleasure craft are no longer legally allowed to use low-tax fuel oil; instead, taxable diesel must be used for fuel.


Currently there are no naked-eye visible dyes in car fuels sold in Poland. Previously, during the time of Communist Party rule, the state-owned CPN fuel monopoly dyed leaded gasolines (marketed as "ethilins") in the following colors: 78 – blue, 86 – green, 94 – yellow, 98 – red. Diesel fuel, although unleaded, was also dyed a brown color.

Fuel dye in North America[edit]

In the United States of America, the Environmental Protection Agency mandates use of a red dye to identify fuels for off-road use. Solvent Red 26 is used in the United States as a standard, though it is often replaced with Solvent Red 164, which is similar to Solvent Red 26 but with longer alkyl chains. The Internal Revenue Service regulation 26 CFR 48.4082-1 mandates use of the same red dyes, in fivefold concentration, for tax-exempt diesel fuels such as heating oil; their argument for the higher dye content is to allow detection even when diluted with "legal" fuel. Detection of red-dyed fuel in the fuel system of an on-road vehicle will incur substantial penalties.

Fuel laundering[edit]

Organised crime gangs may "launder" low-price dyed fuel, removing the dye and selling it illegally to unsuspecting motorists at the higher price of undyed fuel. Paramilitary groups connected to political unrest in Northern Ireland have established laundering plants on both sides of the Irish border. In 2004, Northern Irish police discovered an illegal facility capable of removing the dye from 12 million L (2.6 million imp gal; 3.2 million US gal) per year.[9] In 2009, customs officials shut down a plant capable of removing the dye from 6.5 million litres of fuel per year.[10] In 2011, a plant capable of processing 30 million litres was discovered.[11]

Fuel theft[edit]

Fuel is being dyed by companies such as Bord na Móna in Ireland in an effort to combat the widespread theft of fuel.[12]

Dyes used by country[edit]

Some dyes required in some countries are listed here:

Country Fuel Dye
 Australia Regular unleaded petrol undyed – clear to yellow (was purple or brown up to 2013, was red/orange until 2015)[13][14]
Premium unleaded petrol undyed – clear to yellow[14]
 Austria Heating oil any red dye and Solvent Yellow 124
 Canada Off-road fuel (agriculture, construction, mining etc.) red/purple dye
Marine gasoline any red dye
Heating oil any red dye
 Finland Heating oil Solvent Yellow 124
Diesel for construction and agriculture Solvent Yellow 124
 France Diesel (off-road) Solvent Red 24 and Solvent Yellow 124[15]
Heating oil Solvent Red 24 and Solvent Yellow 124[16]
Kerosene as heating fuel Solvent Yellow 124[17]
Marine diesel Solvent Blue 35
 Latvia Solvent Yellow 124. SIA "Straujupīte" for diesel labeling is using no more than 0.2% of sulfur content.[18]

Diesel is labeled by adding one of the coloring matters to 1000 liters of oil products:

  • (N-ethyl-1- (4-fenilazofenilazo) naphthyl-2-amine – at least 5.0 grams;
Agricultural diesel[19] fiscal marker – Solvent Yellow 124, CAS Nr.34432-92-3 – at least 6.0 grams, and no more than 9.0 grams, per 1000 L
Solvent Blue 35, CAS no. 17354-14-2, or any other equivalent blue coloring – at least 7.0 grams per 1000 L[20]
 Estonia Heating oil Automate Red NR or similar
Agricultural diesel Automate Blue 8 GHF or similar
 Germany Heating oil Solvent Yellow 124 + 4.1 gr/litre Solvent Red 19 or 5.3 gr tolyazotolyazo-ethylhexylbetanaphthylamine or 6.1 gr tolyazotolyazo-tridecylbetanaphthylamine and similar
 Greece Heating oil any red dye
Marine diesel any black dye
 Hungary Heating oil Ferrocene
 India Subsidised Kerosene Blue dye
 Indonesia Pertalite (RON 90) Green dye
PERTAMAX (RON 92) Blue dye
PERTAMAX Turbo (RON 98) Red dye
 Ireland Gas oil green dye = Solvent Yellow 124 and Anthraquinone Blue dye equivalent to Solvent Blue 35 and ACCUTRACE S10 ((3-(sec-butyl)-4-(decyloxy)phenyl)methanetriyl)tribenzene]][21]
Kerosene Solvent Red 19, Solvent Yellow 124 and ACCUTRACE S10 ((3-(sec-butyl)-4-(decyloxy)phenyl)methanetriyl)tribenzene[21]
 Italy Heating oil Solvent Red 161
Gas oil Solvent Green 32 or 33 and Solvent Yellow 124
 Netherlands Agricultural diesel any red dye and Solvent Yellow 124 (the additive Furfural is obsolete)
 Norway Agricultural diesel any green dye
 Portugal Agricultural diesel Solvent Blue 35
Heating oil Solvent Red 19 and similar
 Spain Agricultural diesel any red dye + Solvent Yellow 124: Orden PRE/1724/2002 of 5 July.
Heating oil any blue dye + Solvent Yellow 124: Orden PRE/1724/2002 of 5 July.
 Sweden Heating oil Solvent Blue 35, Solvent Blue 79, Solvent Blue 98 and Solvent Yellow 124
 Thailand Gasoline 95 yellow dye
Gasoline 91 red dye
 United Kingdom Gas oil ("red diesel") Solvent Red 24, quinizarin, Solvent Yellow 124 and ((3-(sec-butyl)-4-(decyloxy)phenyl)methanetriyl)tribenzene[22]
Rebated kerosene Coumarin, Solvent Yellow 124 and ((3-(sec-butyl)-4-(decyloxy)phenyl)methanetriyl)tribenzene[22]
 Europe many rebated Solvent Yellow 124 ("Euromarker") Transition commenced to replace this by ButoxyBenzene from 18 January 2024
 United States low-tax fuels, high-sulfur fuels Solvent Red 26 3.9 lbs per 1000 barrels (11 mg/L), Solvent Red 164
Worldwide Aviation gasoline 80/87 red dye
Aviation gasoline 82UL purple dye
Aviation gasoline 100LL blue dye
Aviation gasoline 100/130 green dye

See also[edit]


  1. ^ "New and better Euromarker for labelling of gas oil and kerosene". European Commission. 17 July 2017.
  2. ^ "Evaluation of the performance of the short-listed candidate markers regarding the technical requirements: Call for expression of interest to present products suitable for use as a marker in gas oils and kerosene". European Commission. 6 July 2017.
  3. ^ "Archived copy" (PDF). Archived from the original (PDF) on 17 April 2018. Retrieved 3 August 2017.{{cite web}}: CS1 maint: archived copy as title (link)
  4. ^ "C/2022/74, Commission Implementing Decision (EU) 2022/197 of 17 January 2022 establishing a common fiscal marker for gas oils and kerosene (Notified under document C(2022) 74)". 17 January 2022.
  5. ^ "Thousands using illegal car fuel". BBC News. 3 November 2007. Retrieved 16 April 2008.
  6. ^ "EC to take UK to court over red diesel". Royal Yachting Association. 14 July 2014. Retrieved 1 August 2014.
  7. ^ "HMRC: New diesel dye 'should eliminate fuel laundering'". BBC News. 18 November 2014.
  8. ^ "Carbon Offset Red Diesel". Crown Oil Ltd. 2014.
  9. ^ "Blackmarket Britain: Fake Fuel". BBC News. 9 June 2004. Retrieved 16 April 2008.
  10. ^ "Illegal fuel plant largest in NI". BBC News. 1 December 2009. Retrieved 1 December 2009.
  11. ^ "UK's biggest fuel laundering plant found in Crossmaglen". BBC News. 16 March 2011. Retrieved 17 March 2011.
  12. ^ "Bord na Móna to dye fuel to fight theft". Irish Times. 11 December 2012. Retrieved 6 June 2015.
  13. ^ "The colour of Australian unleaded petrol is changing to red/orange" (PDF) (Press release). Australian Institute of Petroleum. 28 September 2012. Archived from the original (PDF) on 9 April 2013. Retrieved 22 November 2012.
  14. ^ a b "The Colour of Australian Unleaded Petrol is Changing" (PDF). Australian Institute of Petroleum. Retrieved 28 March 2020.
  15. ^ "Article 3 - Arrêté du 10 novembre 2011 fixant pour le gazole, les gaz de pétrole liquéfiés et les émulsions d'eau dans du gazole des conditions d'emploi ouvrant droit à l'application du régime fiscal privilégié institué par l'article 265 du code des douanes en matière de taxe intérieure de consommation". 30 June 2021. Retrieved 29 January 2023.
  16. ^ "Article 2 - Arrêté du 15 juillet 2010 relatif aux caractéristiques du fioul domestique". 10 December 2010. Retrieved 29 January 2023.
  17. ^ "Article 3 - Arrêté du 18 juillet 2002 fixant pour le white-spirit et le pétrole lampant utilisés comme combustible de chauffage les conditions d'emploi ouvrant droit à l'application du régime fiscal privilégié institué par l'article 265 (tableau B) du code des douanes en matière de taxe intérieure de consommation et fixant les mesures auxquelles doivent se conformer les importateurs et les distributeurs desdits produits". 18 July 2002. Retrieved 29 January 2023.
  18. ^ "Marked fuel - Straujupite.lv - degvielas vairumtirdzniecība". Archived from the original on 3 April 2017. Retrieved 2 April 2017.
  19. ^ "Agro fuel - Straujupite.lv - degvielas vairumtirdzniecība". Archived from the original on 3 April 2017. Retrieved 2 April 2017.
  20. ^ "Par akcīzes nodokli". Likumi.lv (in Latvian). Retrieved 2 April 2017.
  21. ^ a b Gorringe, Jason (22 December 2014). "Ireland To Use New Marker For Lower Duty Fuels". Tax-News.com.
  22. ^ a b "Revenue and Customs Brief 4 (2015): introduction of a new rebated fuel marker from 1 April 2015". Gov.uk.

External links[edit]