Blue 1
Synonyms: Brilliant Blue FCF, FD&C Blue No. 1, CI 42090, E133 (food use); insoluble variant: Blue 1 Lake (Aluminum Lake of CI 42090)
Functions (food/cosmetic/pharma): water-soluble colorant (bright blue), tonalizer, tracer; as a lake, an insoluble pigment for anhydrous/lipid systems
Definition
Blue 1 is a synthetic triarylmethane-type (commonly grouped with azo/triphenylmethane dyes) colorant supplied as the sodium salt, highly water-soluble and used to deliver an intense blue hue to beverages, confections, supplements, pharmaceuticals, and aqueous cosmetics. Blue 1 Lake is the corresponding aluminum lake pigment for oil/anhydrous applications.
Calories (energy value)
0 kcal per 100 g (synthetic colorant; no metabolizable energy).
Composition and structure
Colorant: Brilliant Blue FCF, sodium salt (CI 42090).
Purity: high, with strict heavy-metal limits (Pb, As, Cd, Hg) and tight controls on subsidiary colors.
Physical form: intense blue powder/granules; shade can shift slightly with pH/ionic strength.
Physicochemical properties (indicative)
Solubility: freely soluble in water; insoluble in oils.
λmax (UV–Vis): typically ~628–635 nm in water at neutral pH.
pH tolerance: stable across ~2–10; fading occurs with strong oxidants or reducing agents.
Light/heat stability: good in aqueous systems; complexation with metal ions may affect tone (use chelators if needed).
Compatibility: excellent in beverages, gels, syrups, shampoos, body washes; use Blue 1 Lake for anhydrous or oil phases.
Manufacturing overview (soluble form)
Synthesis of the chromophore from aromatic intermediates via controlled coupling/sulfonation steps.
Neutralization/salt formation (sodium salt).
Purification (filtration, washing, deionization) to minimize salts, by-products, and metals.
Drying and standardization (moisture, tinctorial strength); optional granulation for dust control/dosing.
(For Blue 1 Lake: co-precipitate the dye onto aluminum hydroxide → wash → dry → micronize/classify.)
Advantages and limitations
Advantages (soluble): pure, brilliant blue, easy aqueous dosing, broad pH stability.
Limitations: bleeding/migration in moist matrices; not suitable for lipid systems (use the Lake). Sensitive to strong redox conditions.
Application areas
Food (E133): beverages, ice pops, icings, confectionery, jellies, decorations, and the aqueous phase of baked goods.
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.
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.
- Pharmaceuticals: coated tablets/capsules, syrups; also used as a visual tracer.
Formulation guidelines
Pre-dissolve in water or glycerin; avoid clumping.
Employ chelators (e.g., EDTA, citrate) to mitigate metal-ion effects (haze/tone shifts).
Maintain pH 2–9 for optimum stability; avoid strong oxidants/reductants.
In high-electrolyte systems, check for haze and adjust ionic strength/chelators.
For anhydrous/oily products, pre-disperse Blue 1 Lake in a low-viscosity ester/oil and apply sufficient shear (three-roll/ball mill or high-shear mixer).
Safety and regulatory
EU (Cosmetics, Reg. 1223/2009): CI 42090 listed in Annex IV (approved colorants) with purity specs; generally allowed across categories within spec.
EU (Food): E133 authorized with category-specific limits and an ADI; observe local regulations.
USA (FDA): FD&C Blue No. 1 and its Aluminum Lakes are certifiable color additives; batch certification required. Some drug/cosmetic uses require label declaration.
Hypersensitivity: overall low incidence; rare reactions may occur in predisposed individuals.
Heavy metals: comply strictly with limits for Pb, As, Cd, Hg (and antimony for lakes).
Stability, storage, quality
Store cool, dry, and light-protected in sealed, opaque containers.
Shelf life: typically 36–60 months when properly stored.
QC controls: UV–Vis identity/strength (λmax, absorbance), tinctorial strength, solution pH, insolubles, trace metals.
Troubleshooting
Fading/discoloration: presence of oxidants/reductants or extreme pH—adjust formulation, add suitable antioxidants, and buffer pH.
Haze/precipitation in hard-water beverages: introduce chelators (EDTA/citrate) or reduce ionic load.
Migration in icings/creams: consider partial replacement with Blue 1 Lake in fat phases.
Conclusion
Blue 1 (CI 42090 / E133) is a workhorse water-soluble blue for aqueous foods, cosmetics, and pharmaceuticals, offering bright color and robust pH stability. The Lake form extends use to oily/anhydrous systems. With appropriate purity control, metal chelation, pH management, and Lake co-use where needed, it delivers clean, reproducible, and compliant color performance.
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:
- Erioglaucine A
- 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
Blue 1 
