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".

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.

It is advantageous to mix a liquid with a liquid instead of handling powdered dyes into a liquid.

The pure dyes found in modern liquid petroleum dyes are essentially 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 essentially 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 ultimately they are still lower cost per active molecule of dye chromphore 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).

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 fueling an aircraft with the wrong kind of fuel).

Fuel dye in the European UnionEdit

After August 2002, all European Union countries became obliged to add about 6 mg/L of Solvent Yellow 124, a dye with structure similar to Solvent Yellow 56, to all motor diesel 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%.

United Kingdom Edit

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, highly unlikely in a metropolitan area but much more likely in a rural area. Unauthorized use incurs heavy fines and/or confication of the vehicle, but despite this spot checks have occasionally found as many as one in five motorists using red diesel.[1] Red diesel can also be used in road vehicles which are registered as SORN with the DVLA provided they are only used on private land. There is also no need to tax a vehicle that is not used on a public road.

Carbon Offset Red Diesel

Carbon Offset Red Diesel is now available in the UK. It is an environmentally friendly alternative to regular red diesel. There is an extra cost incurred when purchasing Carbon Offset Red Diesel, however some 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 Carbon Offset Red Diesel.[2]

Poland Edit

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

Fuel dye in North AmericaEdit

In United States of America, the Environmental Protection Agency mandates use of a red dye to identify high-sulfur 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 C.F.R. 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.

Blue dyes are used for diesel designated for governmental and institutional vehicles, to detect theft.[citation needed]

Fuel launderingEdit

Processing fuel to remove the dye so it may be illicitly sold to motorists is a recognized criminal activity in Ireland and the United Kingdom. In Northern Ireland and the Republic of Ireland it has been a means of fund raising by illegal paramilitary organizations. In 2004, Northern Irish police discovered an illegal facility capable of removing the dye from 12 million litres of fuel per year.[3] In 2009, customs officials shut down a plant capable of removing the dye from 6.5 million litres of fuel per year.[4] In 2011, a plant capable of processing 30m litres was discovered.[5]

Dyes usedEdit

Some dyes required in some countries are listed here:

Country Fuel Dye
Flag of Australia.svg Australia Regular Unleaded Petrol Purple (or Bronze)
Premium Unleaded Petrol Yellow
Flag of Austria.svg Austria Heating oil any red dye
Flag of Canada.svg {{{name}}} Agricultural Fuel red/purple dye
Heating oil any red dye
Flag of Finland.svg Finland Heating oil Furfural and Solvent Yellow 124
Diesel for construction and agriculture Furfural and Solvent Yellow 124
Flag of France.svg France Gas oil Solvent Red 24
Marine diesel Solvent Blue 35
Flag of Estonia.svg Estonia Heating oil Automate Red NR or similar + Solvent Yellow 124
Agricultural diesel Automate Blue 8 GHF or similar + Solvent Yellow 124
Flag of Germany.svg Germany Heating oil Solvent Yellow 124 and similar
Flag of Greece.svg Greece Heating oil any red dye
Marine diesel any black dye
Flag of Ireland.svg Ireland Gas oil green dye
Kerosene Solvent Red 19 and similar
Flag of Italy.svg Italy Heating oil Solvent Red 161
Gas oil Solvent Green 32 or 33
Flag of the Netherlands.svg Netherlands Agricultural diesel any red dye and the additive Furfural
Flag of Norway.svg Norway Agricultural diesel any green dye
Flag of Portugal.svg Portugal Agricultural diesel Solvent Blue 35
Heating oil Solvent Red 19 and similar
Flag of Spain.svg Spain Agricultural diesel any red dye
Heating oil any blue dye
Flag of Sweden.svg Sweden Heating oil Solvent Blue 35, Solvent Blue 79, Solvent Blue 98
Flag of Thailand.svg Thailand Gasoline 95 yellow dye
Gasoline 91 red dye
Flag of the United Kingdom.svg United Kingdom Gas oil ("Red Diesel") Solvent Red 24, quinizarin
Rebated kerosene Coumarin
Flag of Europe.svg Europe many rebated Solvent Yellow 124 ("Euromarker")
Flag of the United States.svg United States low-tax fuels, high-sulfur fuels Solvent Red 26, 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


External linksEdit

Smallwikipedialogo This page uses some content from Wikipedia. The original article was at Fuel dyes. The list of authors can be seen in the page history. As with Tractor & Construction Plant Wiki, the text of Wikipedia is available under the Creative Commons by Attribution License and/or GNU Free Documentation License. Please check page history for when the original article was copied to Wikia

Community content is available under CC-BY-SA unless otherwise noted.