Solvent Red 26, also known as Oil Red EGN or C.I. 26120, is a purplish red synthetic

azo dye Azo dyes are organic compounds bearing the functional group R−N=N−R′, in which R and R′ are usually aryl and substituted aryl groups. They are a commercially important family of azo compounds, i.e. compounds containing the C-N=N ...

. It is soluble in oils and insoluble in water. Its main use is as a standard fuel dye in the US mandated by the US IRS to distinguish low-taxed or tax exempt

heating oil Heating oil is any petroleum product or other oil used for heating; a fuel oil. Most commonly, it refers to low viscosity grades of fuel oil used for furnaces or boilers use for home heating and in other buildings. Home heating oil is often a ...

from automotive diesel fuel, 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 Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

content; it is however increasingly replaced with Solvent Red 164, a similar dye with longer alkyl chains, which is better soluble in hydrocarbons.{{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