Solvent Red 26, also known as Oil Red EGN or C.I. 26120, is a purplish red synthetic azo dye. It is soluble in oils and insoluble in water. Its main use is as a standard

fuel dye 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 "w ...

in the US mandated by the US

IRS The Internal Revenue Service (IRS) is the revenue service for the United States federal government, which is responsible for collecting U.S. federal taxes and administering the Internal Revenue Code, the main body of the federal statutory tax ...

to distinguish low-taxed or tax exempt heating oil from automotive

diesel fuel Diesel fuel , also called diesel oil, is any liquid fuel specifically designed for use in a diesel engine, a type of internal combustion engine in which fuel ignition takes place without a spark as a result of compression of the inlet air and ...

, and by the

EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

to mark fuels with higher sulfur content; it is however increasingly replaced with

Solvent Red 164 Sudan III is a lysochrome (fat-soluble dye) diazo dye. It is structurally related to azobenzene. Uses It is used to color nonpolar substances such as oils, fats, waxes, greases, various hydrocarbon products, and acrylic emulsions. Its main ...

, a similar dye with longer

alkyl In organic chemistry, an alkyl group is an alkane missing one hydrogen. The term ''alkyl'' is intentionally unspecific to include many possible substitutions. An acyclic alkyl has the general formula of . A cycloalkyl is derived from a cycloa ...

chains, which is better soluble in

hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...

s.{{cite web , url=http://www.chevron.com/products/prodserv/fuels/bulletin/diesel/L2_3_9_rf.htm , title= L2_3_9_rf, website=www.chevron.com , archive-url=https://web.archive.org/web/20050510225159/http://www.chevron.com/products/prodserv/fuels/bulletin/diesel/L2_3_9_rf.htm , archive-date=May 10, 2005 The concentration required by IRS is a spectral equivalent of 3.9 pounds per 1000 barrels, or 11.13 mg/L, of Solvent Red 26 in solid form; the concentrations required by EPA are roughly 5 times lower.

References

Azo dyes Solvent dyes Fuel dyes 2-Naphthols

See also

References