Aniline Yellow is a yellow

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 ...

and an aromatic amine. It is a derivative of azobenzene. It has the appearance of an orange powder. Aniline Yellow was the first

. it was first produced in 1861 by C. Mene. The second azo dye was Bismarck Brown in 1863. Aniline Yellow was commercialized in 1864 as the first commercial azo dye, a year after

Aniline Black Polyaniline (PANI) is a conducting polymer and organic semiconductor of the semi-flexible rod polymer family. The compound has been of interest since the 1980s because of its electrical conductivity and mechanical properties. Polyaniline is one of ...

. It is manufactured from aniline.

Uses

Aniline Yellow is used in

microscopy Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...

for vital staining, in

pyrotechnics Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. ...

for yellow colored smokes, in yellow pigments and inks including inks for inkjet printers. It is also used in insecticides, lacquers, varnishes, waxes, oil stains, and styrene resins. It is also an intermediate in synthesis of other dyes, e.g.

chrysoidine This is a list of dyes with Colour Index International generic names and numbers and CAS Registry numbers. Note * Synonyms should be treated with caution because they are often used inconsistently, see discussion page and external lin See also ...

indulines Induline is a dye of blue, bluish-red or black shades. Induline consists of a mixture of several intensely colored species, so the name is often indulines. It was one of the first synthetic dyes, discovered in 1863 by J. Dale and Heinrich Caro. The ...

, Solid Yellow, and Acid Yellow.

Toxic oil syndrome

Aniline Yellow was initially implicated in the 1981 Spanish Toxic Oil Syndrome (TOS), although further study suggested the cause was likely contaminated tomatoes. A Madrid-based company imported denaturated

rapeseed oil Close-up of canola blooms Canola flower Rapeseed oil is one of the oldest known vegetable oils. There are both edible and industrial forms produced from rapeseed, the seed of several cultivars of the plant family Brassicaceae. Historically, i ...

, dyed by aniline yellow to mark it as unsuitable for human consumption, to be used as a fuel in

steel mill A steel mill or steelworks is an industrial plant for the manufacture of steel. It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finish ...

s. However, the company distilled the oil to remove the dye, and sold it as a much more valuable

olive oil Olive oil is a liquid fat obtained from olives (the fruit of ''Olea europaea''; family Oleaceae), a traditional tree crop of the Mediterranean Basin, produced by pressing whole olives and extracting the oil. It is commonly used in cooking: f ...

for cooking. The result was a rash of pneumonia-type illnesses, with a second stage with lesions, weight loss,

paralysis Paralysis (also known as plegia) is a loss of motor function in one or more muscles. Paralysis can also be accompanied by a loss of feeling (sensory loss) in the affected area if there is sensory damage. In the United States, roughly 1 in 50 ...

, and muscle wasting. The net result was over 20,000 sick and 400 dead. The chemistry of the poisonous reaction is still subject of a debate.

References

{{Reflist Azo dyes Vital stains Solvent dyes Anilines