CI 42090 is a chemical compound, a dye mainly used in cosmetics and is better known by the name Acid Blue 9 or Brilliant Blue FCF or FD&C Blue No. 1.

It appears as a powder or blue liquid.

The name defines the structure of the compound:

• CI stands for Colour Index, a reference database maintained by the Society of Dyers and Colourists and the American Association of Textile Chemists and Colourists. The Colour Index assigns unique numbers to each dye or pigment.
• 42090 is the specific Colour Index number assigned to a synthetic blue dye known as FD&C Blue No. 1 or Brilliant Blue FCF.

The synthesis process takes place in different steps:

• Production of basic compounds. The first stage begins with the production of basic compounds such as aniline, a benzene derivative, in reaction with other chemicals to produce a compound called sulphanilic acid.
• Diazotization. Sulphanilic acid is diazotised by converting an amine group of sulphanilic acid into a diazonium compound.
• Coupling. The diazonium compound is coupled with another compound, typically an H acid (8-amino-1-naphthol-3,6-disulphonic acid). This coupling reaction leads to the formation of the bright blue dye FCF.
• Purification. The dye is purified, typically through a washing and filtration process.

Cosmetics

It was admitted to the list of authorised colourants in cosmetic products by Directive 76/768/ECC.

It is used as a direct colouring agent in hair colouring products. Its concentration in the finished cosmetic product must not exceed 0.5%. It is also subject to cosmetic restrictions IV/63 and III/190.

Food

In the food industry, it is included in the list of colouring food additives under the number E133. In 1970 FAO/WHO Expert Committee on Food Additives established an acceptable daily intake (ADI) of 0-12.5 mg/kg body weight. The Scientific Committee on Food of the EEC recommended an ADI of 10 mg/kg body weight in 1983.

CI 42090 Acid Blue 9 studies

• Molecular Formula: C₃₇H₄₂N₄O₉S₃
• Molecular Weight: 782.942 g/mol
• UNII: 86R7G3C26F
• CAS: 2650-18-2  1334-07-2  29519-65-1  37307-55-4  37307-56-5  37307-78-1  51609-24-6  55819-29-9  86924-52-9  99149-43-6  511534-54-6
• EC Number: 220-168-0  223-339-8
• PubChem Substance ID 329769043
• MDL number MFCD00012141
• Colour Index Number 42090

Synonyms:

• FD&C Blue No. 1
• Acid Blue 9
• C.I. Acid Blue 9
• Erioglaucine
• E133
• Kiton Pure Blue L
• Pro-Jet Blue OAM
• Erioglaucine (VAN)
• Daiwa Blue 109H
• Japan Blue 205
• Eriosky Blue
• Amacid Blue FG Conc
• Duasyn Acid Blue AE
• Orient Water Blue 9
• Schultz No. 770
• Caswell No. 007A
• CI Direct Brown 78
• Edicol Supra Blue E6
• Vitasyn Blue AE 85
• AF Blue No. 1
• Alphazurine (indicator)
• Xylene Blue VSG
• Acid Sky Blue A
• Alphazurine FG
• Erioglaucine E
• Alphazurine FGND
• Neptune Blue WF
• Fenazo Blue XR
• Patent Blue AE
• Calcocid Blue EG
• Kiton Blue AR
• Neptune Blue BRA
• Patent Blue 2Y
• Tortrazine C extra
• Calcocid Blue 2G
• Water Blue 9
• Bucacid Azure Blue
• Hidacid Azure Blue
• Acid Blue AE-SF
• Bleu Brilliant FCF
• Brilliant Blue Lake
• Aizen Brilliant Blue FCF
• Maple Brilliant Blue FCF
• C.I. Direct Brown 78
• Triantine Light Brown 3RN
• Acilan Turquoise Blue AE
• Peacock Blue X-1756
• CI ACID BLUE 9
• CI Acid Blue 9, diammonium salt
• D and C Blue No. 4
• Duasyn Acid Blue AE-SF
• A.F. Blue No. 1
• C.I. Acid Blue 9, diammonium salt
• Dolkwal Brilliant Blue

Two clinical studies published in 1974 and 1978 reported positive reactions to Acid Blue 9 between 1% and 14% (1),

In vitro laboratory tests have classified this component as mildly irritating to the eyes (2).

For the complete and detailed analysis of other tests carried out, I refer to this official document (3).

Other studies

Biological Effects of Food Coloring in In Vivo and In Vitro Model Systems.
Merinas-Amo R, Martínez-Jurado M, Jurado-Güeto S, Alonso-Moraga Á, Merinas-Amo T.
Foods. 2019 May 24;8(5). pii: E176. doi: 10.3390/foods8050176.

Theoretical Risk Assessment of Dietary Exposure to Brilliant Blue FCF in Chinese Population.
Wang HL, Ding H, Cao P, Zhang JB, Wu D, Tian J.
Biomed Environ Sci. 2019 Feb;32(2):126-129. doi: 10.3967/bes2019.017.

Understanding the performance of a paper-based UV exposure sensor: The photodegradation mechanism of brilliant blue FCF in the presence of TiO2 photocatalysts in both the solid-state and solution.
Khiabani PS, Soeriyadi AH, Nam EV, Peterson JR, Webb JEA, Thordarson P, Donald WA, Gooding JJ.
Rapid Commun Mass Spectrom. 2019 Mar 22. doi: 10.1002/rcm.8442.

Simultaneous Extraction and Determination of Allura Red (E129) and Brilliant Blue FCF (E133) in Foodstuffs by Column Solid-Phase Spectrophotometry.
Bişgin AT.
J AOAC Int. 2018 Jun 12. doi: 10.5740/jaoacint.18-0073.

Determination of Brilliant Blue FCF by a Novel Solid-state ECL Quenching Sensor of Ru(bpy)32+-poly(sulfosalicylic acid)/GCE.
Chen X, Yin J, Zhang C, Lu N, Chen Z.
Anal Sci. 2017;33(10):1123-1128. doi: 10.2116/analsci.33.1123.

Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation.
Molica F, Nolli S, Fontana P, Kwak BR.
J Vis Exp. 2017 Apr 6;(122). doi: 10.3791/55525.

Advanced Oxidation of Tartrazine and Brilliant Blue with Pulsed Ultraviolet Light Emitting Diodes.
Scott R, Mudimbi P, Miller ME, Magnuson M, Willison S, Phillips R, Harper WF Jr.
Water Environ Res. 2017 Jan 1;89(1):24-31. doi: 10.2175/106143016X14733681696167

Use of Brilliant Blue FCF during vein graft preparation inhibits intimal hyperplasia.
Osgood MJ, Sexton K, Voskresensky I, Hocking K, Song J, Komalavilas P, Brophy C, Cheung-Flynn J.
J Vasc Surg. 2016 Aug;64(2):471-478. doi: 10.1016/j.jvs.2015.02.028.

References____________________________________________________________

(1) H Mikkelsen, J C Larsen, F Tarding. Hypersensitivity reactions to food colours with special reference to the natural colour Annatto Extract (Butter Colour). Archives of Toxicology, Suppl. 1 141-143 (1978).

(2) Cosmital SA. Assessment of the Eye Irritation Potential of Blue 1 (WR 23312) in the Hen’s Egg Test on the Chorioallantoic Membrane (HET-CAM). Final Report. Study No.HC 141. Marly, Switzerland. Sponsored by Wella AG Darmstadt. 2002.

(3) OPINION OF THE SCIENTIFIC COMMITTEE ON COSMETIC PRODUCTS AND NON-FOOD

PRODUCTS INTENDED FOR CONSUMERS - SCCNFP/0787/04 - CONCERNING  ACID BLUE 9 -

23 April 2004