Yellow 5 lake or FD&C Yellow No. 5 lake is a synthetic azo dye, nitrogen-based. It is also known as E102 in the European food coloring list.

The name describes the structure of the molecule.

• FD&C indicates that the color is approved by the United States Food and Drug Administration (FDA) for use in foods, drugs, and cosmetics.
• Yellow No. 5 refers to a particular yellow color, also known as Tartrazine, which is a synthetic dye derived from coal tar.
• Lake indicates that the color has been combined with a substance (often a calcium or aluminum salt) to make it water-insoluble, often used in products that are not meant to dissolve immediately in water.

Yellow 5 Lake
Synonyms: Tartrazine Lake, FD&C Yellow No. 5 Aluminum Lake, CI 19140:1 / :2 / :3 (lakes on different substrates); aqueous analogue: Tartrazine, CI 19140, E102
Functions (cosmetic/food): insoluble colorant (pigment), opacifier, bright yellow tonalizer for anhydrous and lipid systems

Definition
Yellow 5 Lake is the laked (insolubilized) form of Tartrazine, an azo yellow dye converted into a water- and oil-insoluble pigment by precipitating the dye onto an inorganic substrate (typically aluminum hydroxide/oxide from aluminum salts). Unlike water-soluble Tartrazine (CI 19140, E102), the lake disperses as particles and gives clean, stable color in lipsticks, pressed powders, fat-based coatings, and other anhydrous systems.

Calories (energy value)
0 kcal per 100 g (inorganic/organic-supported pigment; no metabolizable energy).

Composition and structure

• Color phase: azo dye Tartrazine (typical loading in the lake ~10–40%, grade-dependent).

• Substrate: aluminum hydroxide/oxide (sometimes with phosphates/aluminum salts) anchoring the dye anions.

• Additives: trace anticaking or surface modifiers per manufacturer.

• Physical form: fine powder (customizable PSD; typical D50 from a few to tens of μm).

Physicochemical properties (indicative)

• Solubility: insoluble in water and oils; forms suspensions/dispersions.

• Opacity: good hiding power in anhydrous bases; in emulsions, performance depends on wetting/dispersants.

• Stability: generally more light/heat stable than the soluble dye; sensitive to highly alkaline pH (>~9) and strong reducing agents.

• Compatibility: broad with waxes, oils, esters, mineral fillers; check interactions with strong chelators and divalent salts.

Manufacturing process (general lake synthesis)

1. Dye solution preparation: dissolve Tartrazine in water at controlled pH/ionic strength.

2. Substrate generation: form aluminum hydroxide in situ (aluminum salt + base) or charge a slurry of hydrated alumina.

3. Laking (co-precipitation/adsorption): add the dye solution to the substrate slurry under controlled pH, temperature, agitation to promote ionic anchoring of the dye onto alumina.

4. Maturation: hold to stabilize adsorption and surface charge.

5. Filtration & washing: remove free salts and unbound dye to spec.

6. Drying & milling: gentle drying then jet-milling/classification to reach target particle-size distribution and dispersibility.

7. Quality control: shade/strength, heavy metals (Pb, As, Cd, Hg) at ultra-low levels, moisture, migration/purity per cosmetic–pharmacopeial and (if applicable) food specs.

Advantages vs water-soluble Tartrazine

• Insolubility prevents bleeding/migration in oily/solvent or low-water systems.

• Processability in lipsticks, pressed powders, nail enamels, fat-based coatings.

• Lower sensitivity to incidental water and moderate pH swings in anhydrous formats.

Application areas

• Cosmetics: lipsticks/lip balms, eye shadows and pressed/loose powders, blush/bronzer, nail polish, sticks; sometimes in soaps and bath bombs (with proper dispersion).

• Food (where permitted as E102 aluminum lake): confectionery coatings, dragees, icings, fat fillings, decorations—preferred when coloring the fat phase or low-aw matrices.

Formulation guidelines

• Pre-disperse the lake in a low-viscosity oil/ester (e.g., MCTs, light esters) with suitable wetting/dispersing agents; avoid agglomeration.

• Apply adequate shear (three-roll mill/ball mill or high-shear mixers) for pressed powders and pigmented emulsions.

• Binders: in powders, combine with magnesium stearate, silicas, modified starches for glide and payoff; in lipsticks, tune waxes (beeswax/candelilla/carnauba) for structure.

• pH: avoid >~9 and reducing environments that can alter the azo chromophore.

• Color design: blend with Red/Blue lakes or iron oxides to reach mustard/ochre/golden hues.

Safety and regulatory

• EU (Cosmetics): CI 19140 (Tartrazine) and its lakes are listed in Annex IV of Reg. 1223/2009 (approved colorants) with purity specs; generally allowed across categories within spec.

• USA (FDA): FD&C Yellow No. 5 and Aluminum Lakes are certifiable color additives (batch certification required). Label declaration is required in drugs/some products due to potential hypersensitivity.

• Food: Tartrazine (E102) has an ADI; in the EU foods containing it require the warning “may have an adverse effect on activity and attention in children.” Use of aluminum lakes is permitted only in specified categories—check local limits.

• Hypersensitivity: rare cases of urticaria/bronchial hyperreactivity, more likely in salicylate-sensitive/asthmatic individuals—ensure appropriate labeling.

• Heavy metals: comply strictly with limits for Pb, As, Cd, Hg and antimony.

The problem associated with azo dyes (monoazo or diazo) is photocatalytic degradation (1) leading to eventual oxidation and subsequent formation of impurities such as aromatic amines (2) some of which have carcinogenic activity.

Stability, storage, quality

• Light/heat: good stability; prefer opaque packaging.

• Humidity: keep dry to prevent caking (still insoluble).

• Shelf life: typically 36–60 months if stored cool, dry, sealed.

• QC: monitor shade, tinctorial strength, PSD (D10/D50/D90), Al content, residual water-soluble dye, and trace metals.

Troubleshooting

• Speckling/agglomerates: improve wetting (lower-viscosity esters, gradual addition under high shear) or pre-micronize.

• Shade drift between lots: harmonize dispersion method and pigment load; use spectrophotometric control (ΔE).

• Unexpected bleeding: uncommon with lakes; if observed, review plasticizers/solvents and reduce residual water-soluble fractions.

Conclusion
Yellow 5 Lake delivers a clean, bright, and stable yellow in oily/anhydrous and powder systems. Its insolubility prevents migration and improves wear versus the soluble dye, making it a workhorse colorant for lip products, face powders, nail enamels, and (where permitted) fat-based food coatings. Selecting the right grade (strength, particle size), designing a robust dispersion, and meeting regulatory purity ensure consistent, safe, and reproducible color performance.

References_____________________________________________________________________

(1) Li M, He W, Liu Y, Wu H, Wamer WG, Lo YM, Yin JJ. FD&C Yellow No. 5 (tartrazine) degradation via reactive oxygen species triggered by TiO2 and Au/TiO2 nanoparticles exposed to simulated sunlight. J Agric Food Chem. 2014 Dec 10;62(49):12052-60. doi: 10.1021/jf5045052. Epub 2014 Nov 24. PMID: 25393426.

Abstract. When exposed to light, TiO2 nanoparticles (NPs) become photoactivated and create electron/hole pairs as well as reactive oxygen species (ROS). We examined the ROS production and degradation of a widely used azo dye, FD&C Yellow No. 5 (tartrazine), triggered by photoactivated TiO2 NPs. Degradation was found to follow pseudo-first order reaction kinetics where the rate constant increased with TiO2 NP concentration. Depositing Au on the surface of TiO2 largely enhanced electron transfer and ROS generation, which consequently accelerated dye degradation. Alkaline conditions promoted ROS generation and dye degradation. Results from electron spin resonance spin-trap spectroscopy suggested that at pH 7.4, both hydroxyl radical (•OH) and singlet oxygen ((1)O2) were responsible for dye discoloration, whereas at pH 5, the consumption of (1)O2 became dominant. Implications for dye degradation in foods and other consumer products that contain both TiO2 and FD&C Yellow No. 5 as ingredients are discussed.

(2) Belai N, White SR. Determination of Unsulfonated Aromatic Amines in FD&C Yellow No. 5 and FD&C Yellow No. 6 by Liquid Chromatography-Triple Quadrupole Mass Spectrometry. J AOAC Int. 2019 Mar 1;102(2):580-589. doi: 10.5740/jaoacint.18-0165. 

Abstract. Background: This paper describes a simple and sensitive ultra-HPLC-triple quadrupole MS (LC-MS/MS) method for the determination of six unsulfonated aromatic amines in the color additives FD&C Yellow No. 5 (Y5) and FD&C Yellow No. 6 (Y6). The six amines determined by this method are aniline (ANL), benzidine (BNZ), 4-aminobiphenyl (4ABP), 4-aminoazobenzene (4AAB), 2-aminobiphenyl (2ABP), and 4-aminobenzonitrile (4ABN). Objective: This method is intended for use in batch certification of the color additives by the U.S. Food and Drug Administration (FDA) to ensure that each lot meets published specifications for coloring foods, drugs, and cosmetics. Methods: A modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) procedure is used for extraction of the amines. Quantitative determination was performed in electrospray positive ionization and multiple-reaction monitoring modes. Results: Validation of the method demonstrated overall recovery of 101-115% and precision of 1.74-9.78% for all analytes. Excellent regression coefficients were obtained, with values >0.999. Conclusions: The validated method was successfully used for the analyses of 30 Y5 and Y6 samples and provided results that are consistent with results from the current method used by FDA, with greater sensitivity and low matrix effects. Highlights: The validation results demonstrate that the new LC-MS/MS method is applicable for use in routine batch certification.